Search

Gastrointestinal tumors account for five of the top 10 causes of mortality from all cancers (colorectal, liver, stomach, esophageal and pancreatic cancer). Mammalian target of rapamycin (mTOR) signaling is commonly dysregulated in various human cancers. As a core component of the mTOR complex 2 (mTORC2), Rictor is a key effector molecule of the PI3K/Akt pathway. A high alteration rate of Rictor has been observed in gastrointestinal tumors, and such Rictor alterations are often associated with resistance to chemotherapy and related adverse clinical outcomes. However, the exact roles of Rictor in gastrointestinal tumors remain elusive. The aim of the present study was to critically discuss the following: i) Mutation and biological characteristics of Rictor in tumors with a detailed overview of Rictor in cell proliferation, angiogenesis, apoptosis, autophagy and drug resistance; ii) the role of Rictor in tumors of the digestive system, particularly colorectal, hepatobiliary, gastric, esophageal and pancreatic cancer and cholangiocarcinoma; and iii) the current status and prospects of targeted therapy for Rictor by inhibiting Akt activation. Despite the growing realization of the importance of Rictor/mTORC2 in cancer, the underlying mechanistic details remain poorly understood; this needs to change in order for the development of efficient targeted therapies and re‑sensitization of therapy‑resistant cancers to be made possible.

The use of small molecule kinase inhibitors, which target specific enzymes that are overactive in cancer cells, has revolutionized cancer patient treatment. To treat some types of breast cancer, CDK4/6 inhibitors, such as palbociclib, have been developed that target the phosphorylation of the retinoblastoma tumor suppressor gene. Acquired resistance to CDK4/6 inhibitors may be due to activation of the AKT pro‑survival signaling pathway that stimulates several processes, such as growth, metastasis and changes in metabolism that support rapid cell proliferation. The aim of the present study was to investigate whether targeting ATP citrate lyase (ACLY), a downstream target of AKT, may combine with CDK4/6 inhibition to inhibit tumorigenesis. The present study determined that ACLY is activated in breast and pancreatic cancer cells in response to palbociclib treatment and AKT mediates this effect. Inhibition of ACLY using bempedoic acid used in combination with palbociclib reduced cell viability in a panel of breast and pancreatic cancer cell lines. This effect was also observed using breast cancer cells grown in 3D cell culture. Mechanistically, palbociclib inhibited cell proliferation, whereas bempedoic acid stimulated apoptosis. Finally, using Transwell invasion assays and immunoblotting, the present study demonstrated that ACLY inhibition blocked cell invasion, when used alone or in combination with palbociclib. These data may yield useful information that could guide the development of future therapies aimed at the reduction of acquired resistance observed clinically.

Icariin (ICA) is one of the main bioactive monomer belonging to the flavonoid glycosides that has been widely studied in multiple diseases, including lung cancer. Although ICA has shown anticancer effects, its specific molecular mechanism of action remains to be elucidated. In the present study, the expression of microRNA (miR)‑205‑5p and Phosphatase and tensin homolog deleted on chromosome ten (PTEN) in human lung cancer and bronchial cells were analyzed. Cell viability, colony formation, migration, invasion, apoptosis and cell cycle distribution were investigated in vitro . In addition, the function of ICA on tumor growth was determined using a xenotransplantation model. The results showed that ICA decreased the viability of lung cancer cells. In addition, miR‑205‑5p was upregulated in lung cancer tissues but downregulated following ICA treatment, while PTEN showed a significantly lower expression in lung cancer cells. miR‑205‑5p could increase cancer cell proliferation, migration, invasion and cell cycle progression while suppressing cell apoptosis. Importantly, rescue experiment results showed that ICA could target the miR‑205‑5p/PTEN axis to affect the PI3K/Akt signaling, thereby suppressing the malignant cell phenotype of lung cancer. Finally, animal experiments confirmed that ICA could inhibit lung cancer growth in vivo. Taken together, our findings suggest that miR‑205‑5p is a key gene targeted by ICA to inhibit lung cancer progression.

Hepatocellular carcinoma (HCC) is a malignant tumor with a high metastatic rate. Recent studies have shown that the mitosis‑associated spindle‑assembly checkpoint regulatory protein spindle pole body component 25 homolog (SPC25) promotes HCC progression, although the underlying mechanism has yet to be fully elucidated. The aim of the present study was to investigate the mechanism through which SPC25 may promote HCC progression in greater detail. First, the expression of SPC25 was analyzed in publicly available databases to explore the association between SPC25 and HCC metastasis. Western blotting was subsequently performed to examine the level of SPC25 expression in different HCC cell lines. SPC25 was then silenced in HCCLM3 and Huh7 cells, and the effects of SPC25 silencing were investigated using cell proliferation, wound‑healing, Transwell migration assays and an in vivo mouse model. Finally, the mechanism of SPC25 action with respect to the promotion of HCC metastasis was explored using microarray analysis and rescue experiments. The results obtained demonstrated that SPC25 is highly expressed in HCC, and this high level of expression is associated with poor prognosis and metastasis. Moreover, SPC25 silencing led to a marked inhibition of the invasion and migration of HCC cells both in vitro and in vivo . The gene‑expression profiling and mechanistic experiments suggest that SPC25 preferentially influences the expression of genes associated with extracellular matrix (ECM)‑integrin interactions, including integrin subunit β4 (ITGB4), an upstream element of the integrin pathway. ITGB4 upregulation partly reversed the decline in cell invasion and migration capacities that resulted from SPC25 silencing. Furthermore, deleting both SPC25 and ITGB4 caused a decrease in the phosphorylation of focal adhesion kinase (FAK), phosphoinositide 3‑kinase (PI3K) and AKT, which are downstream elements of the integrin pathway. Taken together, the results of the present study demonstrated the important role of SPC25 as a prognostic indicator and as a promoter of metastasis in HCC, and the underlying mechanism of its action has been partially elucidated, suggesting that SPC25 could be used as a biomarker and as a target for therapeutic intervention in the treatment of HCC.

Prostate cancer (PCa) is an androgen‑dependent disease. Androgen receptor (AR) has a crucial role in the development and progression of PCa. Recently, several microRNAs (miRNAs/miRs) involved in AR regulation have been associated with castration‑resistant prostate cancer (CRPC), the terminal stage of PCa. Nevertheless, the precise mechanism remains unclear. The present study aimed to identify a novel miR‑149 regulatory network and potential therapeutic target for CRPC. It was found that ectopic expression of miR‑149 mimic could inhibit AR expression, repress epithelial‑mesenchymal transition, induce cell cycle arrest and apoptosis in CRPC cell line C4‑2, whereas the miR‑149 inhibitor exerted the opposite effects. Furthermore, it was also revealed that miR‑149 could reduce the functional activity of the PI3K/Akt1 signaling pathway by targeting Akt1 protein, the key regulatory factor of the PI3K/Akt1 signaling pathway. Knockdown of Akt1 by short hairpin RNA increased apoptosis, reduced proliferation, and restrained migration and invasion in CRPC cells, with the effect of AR inhibition. In conclusion, these results revealed that miR‑149 acts as a tumor suppressor in CRPC cell line C4‑2 and restrains its progression through the AR signaling pathway by targeting Akt1. The miR‑149/Akt1/AR regulatory pathway may represent a novel PCa therapeutic target.

The main purpose of the present study was to elucidate the role of sperm‑associated antigen 6 (SPAG6) in the occurrence and development of Burkitt lymphoma (BL) and explore the underlying molecular mechanisms. A correlation was observed between the expression of SPAG6 and the prognosis of patients with lymphoma using The Cancer Genome Atlas (TCGA) database analysis. It was demonstrated that the levels of SPAG6 in BL cells were higher compared with that in IM‑9 cells by reverse transcription‑PCR and western blot assays. Moreover, silencing of SPAG6 significantly decreased proliferation and increased apoptosis of Daudi and Raji cells, whereas SPAG6 overexpression exerted the opposite effects on CA46 and NAMALWA cells. When investigating the possible mechanism, it was first observed that the level of phosphatase and tensin homolog (PTEN) protein was significantly increased, while that of phosphorylated (p‑)AKT protein was markedly reduced in the SPAG6‑knockdown group compared with the blank control group in Daudi and Raji cells by western blot analysis. It was further ascertained whether the phosphoinositide 3‑kinase (PI3K)/PTEN/protein kinase B (AKT) pathway mediates the effects of SPAG6 on cell proliferation and apoptosis, and the results demonstrated that silencing of SPAG6 suppressed the viability of Daudi and Raji cells, whereas PTEN knockdown using siRNA or SF1670 (a specific PTEN inhibitor) reversed the inhibitory effect on cell proliferation and the promoting effect on cell apoptosis induced by SPAG6 depletion in vitro as well as in vivo. These data revealed that SPAG6 may promote the proliferation and inhibit the apoptosis of BL cells via the PTEN/PI3K/AKT pathway. The results of the present study suggest that SPAG6 may play a key role in the progression of BL and may be of value as a predictive prognostic biomarker in patients with BL.

The high activation of protein kinase B (AKT)/nuclear factor‑κB (NF‑κB) signaling has often been associated with the induction of non‑small cell lung cancer (NSCLC) cell survival and resistance to cisplatin, which is one of the most widely used chemotherapeutic drugs in the treatment of NSCLC. The inhibition of AKT/NF‑κB can potentially be used as a molecular target for cancer therapy. Eurycomalactone (ECL), a quassinoid from Eurycoma longifolia Jack, has previously been revealed to exhibit strong cytotoxic activity against the human NSCLC A549 cell line, and can inhibit NF‑κB activity in TNF‑α‑activated 293 cells stably transfected with an NF‑κB luciferase reporter. The present study was the first to investigate whether ECL inhibits the activation of AKT/NF‑κB signaling, induces apoptosis and enhances chemosensitivity to cisplatin in human NSCLC cells. The anticancer activity of ECL was evaluated in two NSCLC cell lines, A549 and Calu‑1. ECL decreased the viability and colony formation ability of both cell lines by inducing cell cycle arrest and apoptosis through the activation of pro‑apoptotic caspase‑3 and poly (ADP‑ribose) polymerase, as well as the reduction of anti‑apoptotic proteins Bcl‑xL and survivin. In addition, ECL treatment suppressed the levels of AKT (phospho Ser473) and NF‑κB (phospho Ser536). Notably, ECL significantly enhanced cisplatin sensitivity in both assessed NSCLC cell lines. The combination treatment of cisplatin and ECL promoted cell apoptosis more effectively than cisplatin alone, as revealed by the increased cleaved caspase‑3, but decreased Bcl‑xL and survivin levels. Exposure to cisplatin alone induced the levels of phosphorylated‑AKT and phosphorylated‑NF‑κB, whereas co‑treatment with ECL inhibited the cisplatin‑induced phosphorylation of AKT and NF‑κB, leading to an increased sensitization effect on cisplatin‑induced apoptosis. In conclusion, ECL exhibited an anticancer effect and sensitized NSCLC cells to cisplatin through the inactivation of AKT/NF‑κB signaling. This finding provides a rationale for the combined use of chemotherapy drugs with ECL to improve their efficacy in NSCLC treatment.

Membranous obstruction of the inferior vena cava (MOVC) has the highest incidence rate among the different types of Budd‑Chiari syndrome (BCS) in China. The inferior vena cava septum of patients with MOVC contains capillaries and the two surfaces of the membrane are composed of vascular endothelial tissue. Membrane formation occurs due to endothelial damage. MicroRNAs (miRNAs/miRs) have been verified to be involved in the pathogenesis and progression of various human diseases. A previous study by our group suggested that miR‑3133 was downregulated in the serum of patients with MOVC. In the present study, the possible mechanistic implication of miR‑3133 in MOVC‑associated processes was further explored. It was observed that miR‑3133 overexpression inhibited, whereas miR‑3133 knockdown enhanced the proliferation and tube formation of human umbilical vein endothelial cells (HUVECs) using the CCK‑8 and tube formation assays. JUNB, a member of activator protein 1 and an important upstream transcriptional molecule of vascular endothelial growth factor (VEGF), was proven to be a direct target gene of miR‑3133 using a bioinformatics prediction and luciferase reporter assay. Meanwhile, the mRNA and protein expression of JUNB and VEGF was determined by PCR, ELISA and western blot analyses. Of note, miR‑3133 overexpression downregulated, while miR‑3133 knockdown elevated the expression of JUNB and VEGF significantly. Furthermore, it was demonstrated that JUNB upregulated the expression and secretion of VEGF to promote HUVEC proliferation and angiogenesis. miR‑3133 was able to inhibit the effect of JUNB overexpression to promote cell proliferation, angiogenesis and the expression of VEGF. In conclusion, the present study demonstrated that miR‑3133 regulated endothelial cell proliferation and angiogenesis through the JUNB/VEGF pathway, which may provide an approach for inhibiting diaphragm formation of the inferior vena cava in MOVC.

Chemotherapy is one of the most commonly used treatments for patients with advanced colon cancer, yet the toxicity of chemotherapy agents, such as 5‑fluorouracil (5‑FU), limits the effectiveness of chemotherapy. Ginsenoside Rg3 (Rg3) is an active ingredient isolated from ginseng. Rg3 has been shown to display anticancer effects on a variety of malignancies. Yet, whether Rg3 synergizes the effect of 5‑FU to inhibit the growth of human colon cancer remains unknown. The present study was designed to ascertain whether Rg3 is able to enhance the anti‑colon cancer effect of 5‑FU. The results revealed that combined treatment of Rg3 and 5‑FU significantly enhanced the inhibition of the proliferation, colony formation, invasion and migration of human colon cancer cells (SW620 and LOVO) in vitro. We also found that combined treatment of Rg3 and 5‑FU significantly enhanced the apoptosis of colon cancer cells by activating the Apaf1/caspase 9/caspase 3 pathway and arrested the cell cycle of the colon cancer cells in G0/G1 by promoting the expression of Cyclin D1, CDK2 and CDK4. In addition, the PI3K/AKT signaling pathway in colon cancer cells was suppressed by Rg3 and 5‑FU. In vivo, Rg3 synergized the effect of 5‑FU to inhibit the growth of human colon cancer xenografts in nude mice. Similarly, combined treatment of Rg3 and 5‑FU altered the expression of colon cancer protein in vivo and in vitro. Collectively, the present study demonstrated that ginsenoside Rg3 enhances the anticancer effect of 5‑FU in colon cancer cells via the PI3K/AKT pathway.

Prostate cancer (PCa) is a malignancy with the highest morbidity rate in 105 countries worldwide and was a major cause of cancer‑associated death in men in 2018. Accumulating evidence suggests that microRNAs (miRNAs/miRs) have important functions in the carcinogenesis of PCa, and may provide novel treatment targets. Previous studies have indicated that miR‑16‑5p is associated with PCa. However, the relevance and importance of miR‑16‑5p in PCa carcinogenesis are still not completely understood. In the current study, we aimed to investigate the role and mechanism of miR‑16‑5p in PCa carcinogenesis. The results showed that miR‑16‑5p was markedly downregulated in PCa cells, and MTS assay, colony formation, flow cytometric analyses demonstrated that miR‑16‑5p inhibited PCa cell survival, regulated cell cycle distribution and induced apoptosis. Moreover, luciferase reporter assay and western blot analysis showed that miR‑16‑5p directly targets AKT3 (AKT serine/threonine kinase 3), which is associated with PCa carcinogenesis, and the effects of the downregulation of AKT3 were similar to the effects of upregulation of miR‑16‑5p in PC‑3 cells. In conclusion, our data clarify that miR‑16‑5p has anticancer functions in PCa cells, and our findings provide experimental evidence to highlight the potential value of miR‑targeting treatment strategies for PCa.

The dysregulation of transcription factors contributes to the unlimited proliferation of cancer cells. Transglutaminase 3 (TGM3) has been demonstrated to play a crucial role in physiology and pathology. However, the potential role of TGM3 in colorectal cancer (CRC) remains unknown. In the present study, reverse transcription‑quantitative PCR and immunohistochemistry were utilized to analyze the expression of TGM3 in CRC and adjacent normal tissues. LoVo and HCT116 cell lines were then selected to further investigate the function of TGM3 in the proliferation, invasion and metastasis of CRC both in vitro and in vivo. Finally, western blotting was performed to investigate the molecular mechanisms underlying the effects of TGM3 in CRC. The expression level of TGM3 was significantly downregulated in CRC tissues, and was associated with tumor invasion, metastasis and patient prognosis. Following TGM3 inhibition and overexpression in CRC cells, it was revealed that TGM3 suppressed cell proliferation, potentially via the promotion of apoptosis and cell cycle regulation. Furthermore, TGM3 also inhibited invasion and metastasis. Finally, it was observed that TGM3 inhibited epithelial‑to‑mesenchymal transition and activated phosphorylated AKT serine/threonine kinase in CRC cells. The results from the present study revealed that TGM3 is a tumor suppressor in the progression of CRC, and may be used as a novel target for CRC treatment.

Endometrial cancer (EC) is the second leading type of cancer among women, and its progression is dependent on several factors. The aim of the present study was to examine the effect of solute carrier organic anion transporter family member 4C1 (SLCO4C1) on human EC and determine the underlying molecular mechanism. A total of 57 differentially expressed genes associated with advanced stage and survival were identified in The Cancer Genome Atlas database. In addition, gene ontology analysis indicated that SLCO4C1 was highly expressed in cell differentiation and integral component of plasma membrane. High SLCO4C1 expression in EC tissues was verified by immunohistochemistry. The results demonstrated that the downregulation of SLCO4C1 could significantly suppress the viability, sphere formation, migration and invasion abilities of cells, but enhance apoptosis in EC cell lines. Furthermore, the present results demonstrated that SLCO4C1 had effects on the epithelial‑mesenchymal transition (EMT) phenotype in EC cells and regulated the expression of EMT‑related proteins. Mechanistically, the present study revealed that SLCO4C1 regulated the biological functions of EC cells by inactivating the PI3K/Akt signaling pathway. Collectively, it was demonstrated that the SLCO4C1/PI3K/Akt pathway may play an important role in EC progression and metastasis and serve as a potential biomarker and target for EC diagnosis and treatment.

Osteosarcoma is one of the most malignant bone tumors, and its major threats are aggressive invasion and early tumor metastasis, which result in a poor prognosis and high mortality. Accumulating evidence indicates that ginsenoside compound K (CK) has a significant antitumor effect, particularly on the inhibition of proliferation and invasion of numerous human tumors. In the present study, it was revealed that CK inhibited the viability and proliferation of osteosarcoma cells. Moreover, it was demonstrated that CK induced apoptosis and inhibited the migration and invasion of osteosarcoma cells via apoptotic staining, Annexin V/PI staining, and Transwell invasion assays. Furthermore, at the molecular level, the present results confirmed that apoptosis and invasion‑related proteins were regulated by CK, which was possibly related to the blockade of the PI3K/mTOR/p70S6K1 signaling pathway. In summary, the present findings indicated that CK inhibited viability and proliferation, induced apoptosis, and inhibited the migration and invasion of osteosarcoma cells through the PI3K/mTOR/p70S6K1 signaling pathway.

Ovarian cancer (OC) is highly metastatic due to frequent peritoneal dissemination, and its treatment poses a major challenge in clinical practice. Yes‑associated protein (YAP) is known to be associated with the development of multiple tumors. However, whether targeting YAP can restrain OC progression and the underlying mechanisms have yet to be fully elucidated. In the present study, YAP was found to be highly expressed in OC, and its expression was correlated with the prognosis of OC patients. Moreover, silencing of YAP markedly inhibited the malignant behavior of OC cells, possibly through regulation of the PI3K/Akt/mTOR pathway. Notably, peptide 17, a YAP inhibitor, exerted a significant attenuating effect on OC progression by diminishing the activation of the PI3K/Akt/mTOR pathway in vitro as well as in vivo. Taken together, these findings demonstrated that targeting YAP attenuated OC progression and suggested the potential application of peptide 17 in OC therapy, thus providing new insights into improving the treatment of OC.

Liver cancer is the fifth most commonly occurring cancer in men and the ninth most commonly occurring cancer in women, worldwide, and is associated with a high mortality rate. Sorafenib is a new inhibitor of multiple kinases, that is regarded as standard treatment for liver cancer. Human breast carcinoma metastasis‑suppressor 1 (BRMS1) is a tumor‑suppressor gene, that reduces the metastatic ability of tumor cells without affecting their tumorigenicity. In the present study, a model of BRMS1 overexpression and BRMS1 knockdown was established in HepG2 cells. The results revealed that the proliferation of HepG2 cells was inhibited in response to sorafenib treatment using MTT assay. Furthermore, BRMS1 overexpression enhanced the effect of sorafenib. In addition, expression of inflammatory response‑related genes was increased, while secretion of angiogenesis‑related molecules was decreased, and apoptosis was also activated after sorafenib treatment using qPCR method, and it was further demonstrated that this effect was mediated by inhibition of the PI3K/AKT/mTOR/ERK signaling pathway using western blot analysis. In conclusion, overexpression of BRMS1 potentiated the effect of sorafenib via PI3K/AKT/mTOR/ERK signaling, while knockdown of BRMS1 expression attenuated this effect. These findings may present a novel therapeutic strategy for liver cancer.

Sorafenib is the first‑line drug used in the treatment of liver cancer; however, drug resistance seriously limits the clinical response to sorafenib. The present study investigated the molecular mechanisms of sorafenib resistance in liver cancer cells. The data indicated that forkhead box M1 (FoxM1) was significantly overexpressed in sorafenib‑resistant cells, at the mRNA and protein levels. Knockdown of FoxM1 rendered drug‑tolerant cells sensitive to sorafenib. Furthermore, FoxM1 was upregulated at the transcriptional level. Overexpression of c‑jun was associated with the upregulation of FoxM1. The results of a reporter gene assay, electrophoretic mobility shift assay and chromatin immunoprecipitation assay demonstrated that there is an activator protein‑1 (AP1) binding site in the promoter of FoxM1, located at ‑608 to ‑618. Knockdown of c‑jun significantly decreased the levels of FoxM1, accompanied by enhanced cell sensitivity to sorafenib. Furthermore, the activation of AKT contributed to the upregulation of c‑jun and FoxM1. Inhibition of AKT using BEZ‑235 markedly suppressed the upregulation of c‑jun and FoxM1, and increased the sensitivity of drug‑resistant cells to sorafenib in vitro and in vivo. The data indicated that the activation of the AKT/AP1/FoxM1 signaling axis is an important determinant of sorafenib tolerance.

Skeletal muscle wasting is a feature of cancer cachexia that increases patient morbidity and mortality. Matrine, the main bioactive component of Sophora flavescens, has been approved for the prevention and therapy of cancer cachexia in China. However, to the best of our knowledge, its mechanism in improving muscle wasting remains unknown. The present study demonstrated that matrine increases muscle fiber size and muscle mass in an in vivo CT26 colon adenocarcinoma cachexia mouse model. Concurrently, other cachexia symptoms, including body and organ weight loss, were alleviated. In in vitro experiments, matrine substantially improved C2C12 myoblast differentiation with or without dexamethasone treatment. In addition, matrine reduced C2C12 myotube atrophy and apoptosis induced by dexamethasone, tumor necrosis factor α and conditioned medium. Two E3 ubiquitin ligases, muscle RING‑finger containing protein‑1 and muscle atrophy F-box protein, which are specifically expressed in wasting skeletal muscle, were also significantly downregulated (P<0.05) by matrine both in C2C12 myotubes and skeletal muscle. Furthermore, matrine increased the phosphorylation of Akt, mTOR and FoxO3α in the atrophying C2C12 myotube induced by dexamethasone. In conclusion, matrine can alleviate muscle atrophy and improve myoblast differentiation possibly by inhibiting E3 ubiquitin ligases and activating the Akt/mTOR/FoxO3α signaling pathway.

Glioblastoma multiforme (GBM) is the most malignant intracranial tumor. Although the affected patients are usually treated with surgery combined with radiotherapy and chemotherapy, the median survival time for GBM patients is still approximately 12‑14 months. Identifying the key molecular mechanisms and targets of GBM development may therefore lead to the development of improved therapies for GBM patients. In the present study, the clinical significance and potential function of epithelial membrane protein 1 (EMP1) in malignant gliomas were investigated. Increased EMP1 expression was associated with increasing tumor grade (P<0.001) and worse prognosis in patients (P<0.001) based on TCGA, Rembrandt and CGGA databases for human gliomas. In vitro, gene silencing of EMP1 in U87MG and P3 GBM (primary glioma) cells significantly inhibited tumor proliferation and invasion. In addition, it was revealed that activation of the PI3K/AKT/mTOR signaling pathway is the driving force of EMP1‑promoted glioma progression. Finally, it was demonstrated, using an intracranial GBM animal model, that EMP1 knockdown significantly inhibits tumor growth in vivo and increases overall survival in tumor‑bearing animals. Our research provides new insights into the molecular mechanisms underlying EMP1 knockdown‑mediated inhibition of GBM cell invasion and raises the possibility that targeting of EMP1 may represent a promising strategy for the treatment of GBM.

Programmed cell death 4 (PDCD4) has been identified as a tumor‑suppressor gene that inhibits neoplastic transformation, tumor progression, and protein translation. It has been reported that multiple factors participate in the regulation of PDCD4 mRNA and protein. The endometrium is regulated by changing concentrations of ovarian hormones, such as estrogen and progesterone, and shows periodical changes. However, whether ovarian hormones regulate PDCD4 expression remains unclear. This study aimed to explore the effect and mechanism of estrogen or progesterone on PDCD4 mRNA and protein expression in human endometrial cancer cells. The expression of PDCD4 mRNA and protein in Ishikawa and HEC‑1‑A cells was detected by quantitative real‑time PCR and western blot analysis. The signaling pathway‑related proteins were detected by western blot analysis. The results showed that PDCD4 mRNA levels exhibited no significant changes after treatment with estrogen or progesterone in both Ishikawa and HEC‑1‑A cell lines. Estrogen also had no obvious effect on PDCD4 protein expression. However, progesterone effectively decreased the expression of PDCD4 protein and the PI3K/AKT pathway may be involved in the downregulation of PDCD4 protein induced by progesterone. These results suggest that the downregulation of PDCD4 induced by progesterone affects the therapeutic efficacy of progesterone in human endometrial cancer or endometriosis, which may have important implications for progesterone treatment in the clinic.

Glioma is the most common primary brain tumor and is characterized by a poor prognosis. Protein tyrosine phosphatase 1B (PTPN1), as a non‑transmembrane protein tyrosine phosphatase, has been reported to serve a critical role in different diseases, including cancer. However, the role of PTPN1 in the progression of glioma remains unclear. The present study investigated the expression and clinicopathological characteristics of PTPN1 by analyzing the data from The Cancer Genome Atlas and 136 patients with glioma. It was indicated that PTPN1 was overexpressed in glioma tissues and served as a predictor for poor prognosis in patients with glioma. In addition, a series of in vitro experiments were performed to examine the underlying mechanism of PTPN1 overexpression and the clinical prognosis in patients with glioma. Knockdown of PTPN1 by small interfering RNA suppressed proliferation of glioma cells, including SF295 and A172. In addition, cell mobility was also inhibited by PTPN1 knockdown, downregulating the expression of matrix metallopeptidase 2 (MMP‑2) and MMP‑9. As indicated by western blot analysis, the mitogen‑activated protein kinase (MAPK)/extracellular‑signal‑regulated kinase (ERK) signaling pathway and the phosphatidylinositol 3‑kinase (PI3K)/AKT serine/threonine kinase (AKT) signaling pathway was regulated by PTPN1, while knockdown of PTPN1 significantly suppressed the MAPK/ERK and PI3K/AKT pathways, in addition to the downstream oncogenic transcription factor MYC Proto‑Oncogene. In conclusion, it was demonstrated that PTPN1 is upregulated in glioma tissue and the overexpression of PTPN1 predicted the poor prognosis of patients with glioma. PTPN1 promotes the progression of glioma by activating the MAPK/ERK and PI3K/AKT pathways.

In the western world, there is an increasing trend of occurrence in testicular cancer. Treatment of malignant testicular cancer is primarily combined surgery with various chemical drugs. Propofol has been frequently used as an anesthetic and sedative induction agent, which could modulate different γ‑aminobutyric acid receptors in the central nervous system. Studies demonstrated that propofol activates endoplasmic reticulum stress to induce apoptosis in lung cancer. However, it remains elusive whether propofol regulates caspase and/or mitogen‑activated protein kinase (MAPK) pathways to induce apoptosis in Leydig tumor cells. In the present study, MA‑10 mouse Leydig tumor cells were treated with propofol, and possible signal pathways associated with apoptosis were investigated. Results demonstrated that increasing dosage of propofol (300‑600 µM) for 24 h significantly decreased cell viability in MA‑10 cells (P<0.05). In flow cytometry analysis, the amount of sub‑G1 phase cell numbers in MA‑10 cells was significantly increased by propofol (P<0.05). Additionally, Annexin V/propidium iodide double staining further confirmed that propofol could induce MA‑10 cell apoptosis. Furthermore, cleaved caspase‑8, ‑9 and ‑3, and/or poly(ADP‑ribose) polymerase were significantly activated following treatment of propofol in MA‑10 cells. In addition, c‑Jun N‑terminal kinase, extracellular signal‑regulated kinase 1/2, and p38 were significantly activated by propofol in MA‑10 cells (P<0.05), indicating that propofol may induce apoptosis through the MAPK pathway. Additionally, propofol diminished the phosphorylation of Akt to activate apoptosis in MA‑10 cells. In conclusion, propofol may induce MA‑10 cell apoptosis by activating caspase and MAPK pathways, and inhibiting the Akt pathway in MA‑10 cells, demonstrating that propofol may be a potential anticancer agent against Leydig cell cancer.

Redd1 is a stress response protein that functions as a repressor of mTORC1, a central regulator of protein translation, resulting in the inhibition of cell growth and metabolism. However, paradoxically, high Redd1 expression favors cancer progression and generates resistance to cancer therapy. Herein, we revealed that constitutive overexpression of Redd1 induced HSP27 and HSP70 expression in lung cancer cells. The expression of Redd1, HSP27 and HSP70 was highly increased in lung cancer tissues compared with that in normal lung tissues. Inhibition of HSP27 or HSP70 suppressed AKT phosphorylation, which was induced by constitutive overexpression of Redd1 and enhanced the inhibitory effects on viability of Redd1‑overexpressing cells. Inhibition of AKT phosphorylation resulted in a decrease of HSP27 and HSP70 expression in Redd1‑overexpressing cells. These data indicated that HSPs and AKT in Redd1‑overexpressing cells positively regulated the function and expression of each other and were involved in lung cancer cell survival. Knockdown of HSP27, HSP70 or AKT enhanced ionizing radiation (IR) sensitivity, particularly in lung cancer cells in which Redd1 was stably overexpressed. Collectively, constitutive overexpression of Redd1 led to HSP27 and HSP70 induction and AKT activation, which were involved in lung cancer cell survival and resistance to IR, suggesting that Redd1 may be used as a therapeutic target for lung cancer.

Tamoxifen, a selective estrogen receptor (ER) modulator, is the most widely used endocrine therapy for patients with ER‑positive breast cancer. However, ~30% of tamoxifen‑treated breast cancers do not initially respond to tamoxifen, and neither do they eventually develop tamoxifen resistance. Bcl‑2‑associated athanogene 1 (BAG‑1) is a multifunctional protein that interacts with a wide range of molecules to protect cells from apoptosis otherwise induced by cytotoxic drugs, growth factor withdrawal, radiation and stress. The aim of the present study was to investigate the function of BAG‑1 in tamoxifen resistance. Immunohistochemistry techniques were used to determine BAG‑1 expression in 119 stage I‑III primary breast cancer tissues and it was identified that BAG‑1 was significantly overexpressed in ER‑positive breast cancer (P=0.001). Knockdown of BAG‑1 by short interfering RNA was revealed to downregulate ER, and upregulate phospho (p)‑protein kinase B (Akt) and p‑mammalian target of rapamycin (mTOR) levels. Furthermore, significantly decreased tamoxifen‑induced apoptosis (41.70±1.93 vs. 55.03±2.39%; P=0.012) was observed in T47D cells following the silencing of BAG‑1. In contrast, overexpression of BAG‑1 long enhanced apoptosis (65.10±2.35 vs. 55.03±2.39%; P=0.039) in T47D cells treated with tamoxifen. Combination treatment of tamoxifen and an mTOR inhibitor restored the inhibitory effects of tamoxifen in T47D cells exhibiting low BAG‑1 expression levels (66.87±2.27 vs. 57.07±2.46%; P=0.037). In conclusion, there results of the present study indicated that suppression of BAG‑1 expression may activate the phosphoinositide 3‑kinase/Akt/mTOR pathway and protect ER‑positive breast cancer cells from tamoxifen‑induced inhibition of proliferation. ER‑positive breast cancer cells exhibiting low BAG‑1 expression appeared to be more sensitive to treatment with the mTOR inhibitor rapamycin. Furthermore, the results indicated that combination treatment targeting ER with tamoxifen and targeting mTOR with rapamycin may significantly potentiate the inhibitory effect in BAG‑1‑silenced cells.

The present study aimed to further explore the molecular mechanisms of miRNA-223 in non-small cell lung cancer (NSCLC). Data prospectively collected from NSCLC patients and volunteers from March 2016 to MayMAP2016 at Tsinghua Changgung Hospital were analyzed. Cell proliferation was measured using MTT assay, while cell apoptosis and caspase-3/9 activity were measured using flow cytometry and caspase-3/9 activity kit. Bax, EGFR, PI3K and p-Akt protein were also investigated using western blotting. The results revealed that the serum levels of miRNA-223 in NSCLC patients were downregulated. In an inMAPvitro model, over-expression of miRNA-223 induced apoptosis while reducing cell proliferation. In contrast, downregulation of the expression of miRNA-223 inhibited apoptosis whereas it increased cell proliferation. Meanwhile, overexpression of miRNA-223 suppressed the protein expression of EGFR, PI3K and p-Akt in NSCLC cells. An EGFR inhibitor promoted the anticancer effects of miRNA-223 in NSCLC cells through the EGFR/PI3K/AKT pathway. Meanwhile, a PI3K inhibitor increased the anticancer effects of miRNA-223 in NSCLC cells through the PI3K/AKT pathway. Thus, a new pathway has been identified in the present study, and application of miRNA-223 may induce the apoptosis of NSCLC through the PI3K/AKT pathway by EGFR.

Accumulating evidence has implicated that the activation of signal transducer and activator of transcription 3 (STAT3) contributes to the progression of liver cancer by affecting the expression of proliferation‑associated genes. A previous study reported that elevated levels of 17β‑hydroxysteroid dehydrogenase 4 (HSD17B4) are observed in patients with liver cancer. The current study investigated how upregulated HSD17B4 expression promoted the expression of proliferation‑associated genes in rats with liver cancer. HSD17B4 expression in rats with liver cancer was significantly increased compared with the control group as determined by reverse transcription‑quantitative polymerase chain reaction and western blot assays. Immunohistochemical results revealed that STAT3 activation was positively correlated with increased HSD17B4 expression in tumor tissues from patients with liver cancer. Western blot results further suggested that HSD17B4 overexpression increased STAT3 activation via the protein kinase B and the mitogen‑activated protein kinase/extracellular‑signal‑regulated kinase signaling pathways in HepG2 cells. The present study suggested that overexpression may promote HepG2 proliferation by enhancing expression of various downstream targets of STAT3. Targeted inhibition of HSD17B4 may describe a novel approach in the prevention and treatment of liver cancer.

Colorectal cancer (CRC) is the most commonly diagnosed tumor worldwide. However, the molecular mechanisms and biological processes of CRC remain unknown. The present study used reverse transcription-quantitative polymerase chain reaction to determine the expression levels of microRNA (miR)-296 in CRC cell lines and tissues. In addition, a miR-296 mimic was transfected into CRC cells, and the effects of miR-296 on cell proliferation and apoptosis were explored by MTT assay and flow cytometry. Luciferase assays were also performed to validate arrestin β1 (ARRB1) as a miR-296 target in SW480 and HCT-116 cells. The results demonstrated that miR-296 is a critical tumor suppressor which was downregulated in CRC patients. Increased expression levels of miR-296 were positively associated with a longer survival time of CRC patients. In addition, it was demonstrated that ARRB1 is a direct downstream target of miR-296. Upregulation of miR-296 in SW480 and HCT-116 cells resulted in suppressed cell growth and increased cell apoptosis through an ARRB1-dependent mechanism. Furthermore, the molecular mechanisms underlying the antitumor effect of miR‑296 in CRC are at least in part due to the inactivation of the RAC-α serine/threonine-protein kinase (AKT) signaling pathway induced by the suppression of ARRB1 expression. Overall, the present study, to the best of the author's knowledge, is the first to demonstrate that the miR-296-ARRB1-AKT signaling pathway forms a critical feedback loop and mediates CRC carcinogenesis, and these findings may introduce a potential therapeutic strategy for the treatment of CRC.

Phosphatase and tensin homolog (PTEN) deficiency is associated with development, progression, and metastasis of various cancers. However, changes in gene expression associated with PTEN deficiency have not been fully characterized. To explore genes with altered expression in PTEN‑deficient cells, the present study generated a PTEN‑knockout cell line (ΔPTEN) from a mouse prostate cancer‑derived cell line using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR‑associated protein 9 (CRISPR/Cas9) gene editing system. Following transfection of the CRISPR/Cas9 construct, DNA sequencing was performed to identify deletion of the Pten locus and PTEN inactivation was verified by western blotting. The ΔPTEN cell line exhibited enhanced RAC‑alpha serine/threonine‑protein kinase phosphorylation and cyclin D1 expression. In addition, an increase in cell proliferation and colony formation was observed in the ΔPTEN cell line. Gene expression profiling experiments were analyzed with microarray and microRNA (miRNA) arrays. In the microarray analysis, 111 genes exhibited ≥10‑fold increased expression compared with the parent strain and mock cell line and 23 genes were downregulated. The only miRNA with increased expression of 10‑fold or more was mmu‑miR‑210‑3p. Genes with enhanced expression included genes involved in the development, progression, and metastasis of cancer such as Tet methylcytosine dioxygenase 1, twist family BHLH transcription factor 2, C‑fos‑induced growth factor and Wingless‑Type MMTV Integration Site Family, Member 3, and genes involved in immunosuppression such as Arginase 1. The results of the present study suggest that PTEN deficiency mobilizes a variety of genes critical for cancer cell survival and host immune evasion.

Tanshinone IIA (Tan‑IIA; C19H18O3) is derived from Danshen (the roots of Salvia miltiorrhiza), and has been reported to possess anti‑inflammatory and antioxidant activities. Tan‑IIA can inhibit BxPC‑3 human pancreatic cancer cells in vitro through inducing endoplasmic reticulum stress and apoptosis via mitochondrial pathways. However, the efficacy and molecular mechanisms of Tan‑IIA in human pancreatic cancer have not yet been elucidated. The transmembrane tyrosine kinases, including insulin‑like growth factor 1 receptor (IGF1R), vascular endothelial growth factor receptor (VEGFR) or epidermal growth factor receptor (EGFR) have been implicated in the survival and metastasis of cancer. In addition, the Ras/Raf/mitogen‑activated protein kinase kinase (MEK)/extracellular signal‑regulated kinase (ERK) and phosphoinositide 3‑kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathways are the most commonly dysregulated kinase cascades in human cancer. The present study aimed to investigate the efficacy and molecular mechanisms of Tan‑IIA in MiaPaCa‑2 human pancreatic carcinoma cells. The protein expression levels of EGFR, IGF1R, VEGFR, Ras, PI3K, AKT, mTOR, Raf, MEK, ERK and phosphatase and tensin homolog (PTEN) were detected in Tan‑IIA‑treated MiaPaCa‑2 cells by western blotting. The results demonstrated that the protein expression levels of EGFR, IGF1R, VEGFR, Ras, Raf, MEK, ERK, PI3K, AKT, mTOR and PTEN were decreased in MiaPaCa‑2 cells treated with various concentrations of Tan‑IIA for different durations. In conclusion, these findings indicated that Tan‑IIA may inhibit MiaPaCa‑2 human pancreatic cancer cells; the molecular mechanisms underlying this inhibitory effect may be involved in downregulating EGFR, IGF1R and VEGFR expression, and dual blockade of the Ras/Raf/MERK/ERK and PI3K/AKT/mTOR pathways.

Upregulated β-galactoside α2,6-sialyltransferase I (ST6Gal-I) expression reportedly occurs in many cancers and is correlated with metastasis and poor prognosis. However, the mechanisms by which ST6Gal‑I facilitates gastric cancer progression remain poorly understood. Trastuzumab is exclusively used in human epidermal growth factor receptor 2 (HER2)+ gastric cancers; however, most advanced HER2+ gastric cancers develop trastuzumab resistance. Herein, we identified HER2 as an ST6Gal‑I substrate and showed that HER2 α2,6 sialylation confers protection against trastuzumab‑mediated apoptosis. SGC7901 cancer cell models in which ST6Gal‑I was overexpressed or knocked down were constructed, revealing that ST6Gal‑I overexpression induced high HER2 sialylation levels and increased cell viability and invasion compared to those in the vector cell line under serum starvation; ST6Gal‑I knockdown had the opposite effects. ST6Gal‑I overexpression also potentiated cell cycle arrest in the G2/S phase to reduce drug sensitivity. In addition, FACS analysis revealed that high ST6Gal‑I levels increased resistance to trastuzumab‑induced apoptosis, accompanied by decreased caspase‑3 levels. However, the ST6Gal‑I knockdown cell line revealed increased caspase‑3 levels and evident apoptosis compared with those in the vector cell line. Although ST6Gal‑I overexpression increased HER2 sialylation, corresponding to decreased HER2 phosphorylation, high α2,6‑sialylation enhanced Akt and ERK phosphorylation levels compared to those in the vector cell line; ST6Gal‑I knockdown had the opposite effects. Collectively, these results implicated a functional role of ST6Gal‑I in promoting tumor cell progression and trastuzumab resistance.

G protein‑coupled receptor 56 (GPR56), a member of the orphan GPCR family, has been reported to be an oncogene in various malignancies. However, little is known regarding the detailed molecular mechanism of GPR56 in colorectal cancer (CRC). The present study aimed to detect the expression level and biological function of GPR56 in CRC. We examined the expression of GPR56 in CRC tissues and cell lines by quantitative real time (qRT)‑PCR, immunohistochemistry, and western blot analysis. The prognostic significance of GPR56 in CRC patients was evaluated by Kaplan‑Meier survival analysis. The influence of GPR56 on tumor cell proliferation (via Cell Counting Kit‑8, and a tumor formation assay in mice), apoptosis (flow cytometry), cell cycle distribution (flow cytometry) and migration (Transwell assay) was explored. We also investigated the underlying mechanism of GPR56 by western blot analysis. We found GPR56 expression was significantly upregulated in CRC tissues and cell lines compared to corresponding normal controls. Higher GPR56 expression in patients predicted poorer prognosis. Depletion of GPR56 markedly suppressed cell proliferation, migration, and invasion. GPR56 overexpression promoted CRC cell metastasis by expediting epithelial‑mesenchymal transition by activating PI3K/AKT signaling. In conclusion, GPR56 played an important role in CRC progression and may represent a new therapeutic target to reduce CRC metastasis.

Gasdermin D (GSDMD) is a newly discovered pyroptosis executive protein, which can be cleaved by inflammatory caspases and is essential for secretion of IL‑1β, making it a critical mediator of inflammation. However, the precise role of GSDMD in carcinogenesis remains nearly unknown. Considering the vital role of inflammation in tumorigenesis, we investigated the biological function of GSDMD in non‑small cell lung cancer (NSCLC). Our study demonstrated that the GSDMD protein levels were significantly upregulated in NSCLC compared to these levels in matched adjacent tumor specimens. Higher GSDMD expression was associated with aggressive traits including larger tumor size and more advanced tumor-node-metastasis (TNM) stages. In addition, high GSDMD expression indicated a poor prognosis in lung adenocarcinoma (LUAD), but not in squamous cell carcinoma (LUSC). Knockdown of GSDMD restricted tumor growth in vitro and in vivo. Notably, intrinsic and extrinsic activation of pyroptotic (NLRP3/caspase‑1) signaling in GSDMD‑deficient tumor cells induced another type of programmed cell death (apoptosis), instead of pyroptosis. GSDMD depletion activated the cleavage of caspase‑3 and PARP, and promoted cancer cell death via intrinsic mitochondrial apoptotic pathways. In addition, co‑expression analyses indicated a correlation between GSDMD and EGFR/Akt signaling. Collectively, our results revealed a crosstalk between pyroptotic signaling and apoptosis in tumor cells. Knockdown of GSDMD attenuated tumor proliferation by promoting apoptosis and inhibiting EGFR/Akt signaling in NSCLC. In conclution, GSDMD is an independent prognostic biomarker for LUAD.

Gefitinib, an epidermal growth factor receptor (EGFR)‑specific drug, is effective for ~1 year, after which resistance is inevitable. Calpain 2 (CAPN2) is known to serve a role in the drug response and resistance in certain cancer therapies. However, the full function of CAPN2, particularly in non‑small cell lung cancer, has not yet been elucidated. In the present study, CAPN2 expression in gefitinib‑resistant lung adenocarcinoma cells was investigated. CAPN2 function in these cells was further evaluated using gene knockdown both in vitro and in vivo. The results demonstrated that CAPN2 was strongly associated with gefitinib‑resistance, and CAPN2 mRNA and protein expression levels were significantly increased in gefitinib‑resistant cell lines. Furthermore, CAPN2 knockdown inhibited gefitinib‑resistant cell proliferation in vitro and in vivo. CAPN2 conferred gefitinib‑resistance by inhibiting cell apoptosis and arresting the cell cycle. CAPN2 knockdown also induced caspase activation and mitochondrial dysfunction, and its function in gefitinib resistance appeared to be largely mediated by EGFR/protein kinase B/survivin signaling pathway activation. These results suggest that CAPN2 is responsible for EGFR‑tyrosine kinase inhibitor resistance, and CAPN2 inhibition may be used to provide therapeutic benefits in the treatment of gefitinib resistance.

Cell division cycle associated 5 (CDCA5) has been associated with the progression of several types of cancers. However, its possible role and mechanism in hepatocellular carcinoma (HCC) remain unknown. In the present study, immunohistochemical staining and real‑time PCR were used to assess CDCA5 protein and mRNA levels in clinical samples. Statistical analysis was performed to explore the clinical correlation between CDCA5 protein expression and clinicopathological features and overall survival in HCC patients. Cell counting and colony formation assays were employed to analyse the effect of CDCA5 on cell proliferation, and flow cytometry was used to study the role of CDCA5 in cell cycle progression and apoptosis. Moreover, subcutaneous xenograft tumour models were implemented to predict the efficacy of targeting CDCA5 in HCC in vivo. We found that CDCA5 expression was significantly higher in HCC tumour tissues, was associated with clinicopathological characteristics, and predicted poor overall survival in HCC patients. Silencing of CDCA5 with small interfering RNA (siRNA) inhibited cell proliferation and induced G2/M cell cycle arrest in vitro. The xenograft growth assay revealed that CDCA5 downregulation impeded HCC growth in vivo. Further study indicated that CDCA5 depletion decreased the levels of ERK1/2 and AKT phosphorylation in vitro and in vivo. Taken together, these results indicate that CDCA5 may act as a novel prognostic biomarker and therapeutic target for HCC.

Nuclear factor I/B (NFIB) plays a crucial role in the progression of several types of cancers. However, its role in gastric cancer (GC) remains unclear. The present study revealed that NFIB was highly expressed in GC tissues and was positively associated with the clinicopathological features of GC patients. Downregulation of NFIB inhibited the tumor growth, migration and aggression of MKN45 and HGC27 cells in vitro. In addition, NFIB expression promoted epithelial‑mesenchymal transition (EMT), which was accompanied with decreased E‑cadherin and increased vimentin expression. Since AKT and Stat3 play an important role in EMT and tumor progression, we examined whether there is a correlation between NFIB and AKT/Stat3 signaling pathways in GC. Our results revealed that NFIB exhibits its oncogenic functions in GC development by regulating the phosphorylation of both AKT and Stat3 molecules. Knocking down the NFIB expression may enhance the phosphorylation of AKT while inhibiting the Stat3 phosphorylation, suggesting that the AKT/Stat3 signaling pathway may be the downstream target of NFIB with which it exerts its roles on GC development. These results revealed that NFIB promotes tumor growth and aggressiveness of GC. In addition, downregulation of NFIB alters the protein kinase B/signal transducers and activators of transcription 3 (AKT/Stat3) axis, which could be a potential molecular mechanism for precise target treatment of GC.

Ultraconserved regions (UCRs) are 481 segments that have been strictly conserved among many mammalian species for hundreds of years. Their transcribed products belong to long non‑coding RNAs and are closely involved in the progression of various tumors. uc.338 has been reported to promote cell proliferation in hepatocellular and lung cancers. However, the role of uc.338 in colorectal cancer (CRC) proliferation remains unclear. In the present study, we first detected the expression of uc.338 in human tissues and analyzed the relationship between uc.338 expression and clinical features of CRC. We then investigated the biological function of uc.338 in CRC proliferation in vitro and in vivo. Finally, we explored the potential mechanism by which uc.338 promotes the proliferation of CRC cells. Our results indicated that uc.338 was upregulated in CRC tissues and higher uc.338 expression was associated with a larger tumor size, deeper invasion, increased lymph node metastasis and poorer prognosis. Further investigations in vivo and in vitro revealed that uc.338 could promote proliferation and cell cycle G1/S transition, and might target p21 downregulation and cyclin D1 upregulation via the PI3K/AKT pathway in CRC cells. Thus, our findings suggested that uc.338 acts as an oncogene by promoting proliferation in CRC cells, and could become a novel target for CRC detection and therapy.

Girdin functions as an Akt phosphorylation enhancer (APE), which expedites the proliferation and survival of many types of tumours. However, the influence of Girdin on pancreatic cancer and the underlying molecular mechanisms have yet to be uncovered. Hence, in the present study, we sought to elucidate the function of Girdin in pancreatic cancer malignancy, particularly its role in pancreatic cancer cell proliferation, migration and apoptosis. Immunohistochemistry (IHC) was used to evaluate Girdin expression in pancreatic cancer tissues and to analyse its correlation with pathological grade. Girdin expression was further validated in pancreatic cancer cell lines (AsPC‑1, BxPC‑3 and PANC‑1), and human pancreatic ductal epithelial (HPNE) cells were used as a control. Recombinant adenovirus vectors containing Girdin‑siRNA were constructed to inhibit Girdin expression and were used in subsequent experiments to determine the effects of Girdin silencing on pancreatic cancer cells. Girdin silencing suppressed pancreatic cancer cell proliferation and induced pancreatic cancer cell apoptosis in vitro and in vivo. According to the results of further mechanistic investigations, Girdin may regulate cell processes through the phosphatidylinositol‑3‑kinase/protein kinase B (PI3K/Akt) signalling pathway to exert additive effects on pancreatic cancer.

δ‑Like ligand 4 (DLL4) has recently been reported to be involved in the process of cancer angiogenesis and considered to play a vital role in vascular endothelial growth factor (VEGF) signaling, while the role of DLL4 in cancer metastasis and growth has not been systematically studied. In the present study, the esophagus cancer cell line Eca109 was infected in vitro with a lentiviral vector loaded with dll4‑shRNA to obtain a stable cell line of DLL4 expression which was downregulated through puromycin screening. The migration and invasion ability of the Eca109 dll4‑shRNA cells were evaluated by scratch and Transwell assays, respectively. The underlying signaling pathway was further explored by western blotting. Subsequently, to explore the role of dll4 in the development of esophagus cancer cells in vivo, a xenograft model was established by intraperitoneal injection with Eca109 dll4‑shRNA cells containing luciferase activity in nude mice. Then, small animal imaging system was used to evaluate the volume and metastatic potential of the tumors. Additionally, the overall survival rate of the nude mice was also recorded. Following infection with lentivirus, the expression of DLL4 in the Eca109 cells could be stably silenced through screening with puromycin, which was confirmed by western blotting. The scratch and Transwell assays demonstrated that downregulated DLL4 significantly diminished the aggressive invasion and migration properties of the Eca109 cells. The underlying mechanisms may be attributed to the inactivation of the PI3K/Akt/E‑cadherin pathway by western blotting. Finally, the results from the in vivo study indicated that the tumor growth rate in the Eca109 dll4‑shRNA group, as displayed by the tumor volume and the weak staining of the proliferating cell nuclear antigen (PCNA), was significantly slower than the control group, and the metastasis ability of the Eca109 dll4‑shRNA cells was also dramatically abolished in vivo. It was also observed that downregulated DLL4 led to the formation of less pulmonary nodules in mice lungs and to a prolonged survival rate of nude mice. In summary, this study revealed that DLL4 has pathophysiological roles on the progression of esophagus cancer cells, including migration, invasion and apoptosis, which indicated that DLL4 may be considered as a potent therapeutic target for the treatment of malignant esophageal cancer.

Puerarin, an isoflavone isolated from Kudzu roots, has been demonstrated to have beneficial effect on cardiovascular and cerebral vascular diseases. Recently research has revealed that puerarin exerts an anticancer role in many different types of cancer. The aim of the present study was to investigate the antitumor effects of puerarin on non-small cell lung cancer (NSCLC). Treatment of puerarin significantly inhibited the growth of NSCLC cell lines as determined by CCK-8 kit in vitro. Flow cytometry results indicated that puerarin treatments promoted NSCLC cell apoptosis. This result was further confirmed by western blot analysis of expression levels of proteins involved in the mitochondrial-mediated apoptosis pathway. Moreover, puerarin slightly induced cell autophagy through the PI3K/Akt and MAPK/Erk1/2 signaling pathways. In addition, a tumor xenograft model was established using nude mice, and the inhibitory effects on tumor growth by puerarin treatment were also detected. Taken together, these findings demonstrated that puerarin has anticancer activities and puerarin is a potential therapeutic agent for lung cancer.

A disintegrin and metalloprotease 17 (ADAM17) is highly expressed in many malignant tumors and is closely related to their development. We showed in a previous study that silencing of ADAM17 by siRNA inhibited the growth of MCF‑7 breast cancer cells in vitro and in vivo. In the present study, we investigated the effects of ADAM17-short hairpin RNA (ADAM17‑shRNA) on MCF‑7 breast cancer cells and explored the potential action pathway. In vitro, transfection of shRNAs was performed using a lentivirus, and the effects of ADAM17‑shRNA on invasion, proliferation and cell cycle distribution of MCF‑7 cells were assessed by Boyden chamber method, real‑time cell analysis and flow cytometry, respectively. In vivo, MCF‑7 cells with different administrations were transplanted subcutaneously into nude mice, and the effect of ADAM17‑shRNA on the growth of transplanted tumors was assessed. In addition, the morphological structures were observed by H&E staining, and the expression of ADAM17 and Ki‑67 was assessed by immunohistochemistry; expression of ADAM17, EGFR, p‑EGFR, AKT, p‑AKT, ERK and p‑ERK proteins was assessed by western blotting, respectively. Our data showed that ADAM17‑shRNA successfully inhibited ADAM17 mRNA expression, invasion and proliferation of MCF‑7 cells resulting in G0/G1 phase arrest, and significantly inhibited the growth of transplanted tumors with larger areas of necrosis, low expression of ADAM17 and Ki-67 and reduced protein expression of ADAM17, EGFR, p‑EGFR, AKT, p‑AKT, ERK, and p‑ERK in the tumor tissues. The present research suggests that ADAM17‑shRNA can inhibit MCF‑7 cell invasion and proliferation in vitro and inhibit MCF‑7 xenograft growth in vivo through the EGFR/PI3K/AKT and EGFR/MEK/ERK signaling pathways.

A number of miRNAs have been found to be abnormally expressed or mutated in numerous cancers and thus, are considered to act as oncogenes or tumor suppressor genes. The aim of the present study was to investigate the effect of miR-181 on cisplatin-resistant non-small cell lung cancer (NSCLC). In patients with cisplatin-resistant NSCLC, miR-181 expression was found to be markedly decreased. In addition, in the cisplatin-resistant human lung adenocarcinoma cell line A549/DDP, miR-181 downregulation promoted cell growth and metastasis and inhibited cell apoptosis, whereas miR-181 overexpression exerted the opposite effects. Furthermore, miR-181 downregulation suppressed LC3 and ATG5 protein expression in A549/DDP cells through suppression of the PTEN/PI3K/AKT/mTOR pathway, whereas miR-181 overexpression recovered LC3 and ATG5 protein expression by promoting PTEN/PI3K/AKT/mTOR signaling. In turn, PTEN inhibitors reduced the anticancer effects of miR-181 overexpression on A549/DDP cell growth via the regulation of autophagy through the PI3K/AKT/mTOR pathway. Therefore, miR-181 may be a novel and important regulator of cisplatin-resistant NSCLC by serving a role in the regulation of apoptosis, as an established rate-limiting miRNA target.

Polygalacin D (PGD) is a bioactive compound isolated from Platycodon grandiflorum (Jacq.) and it has a similar structure to platycodin D, which is a well known anticancer agent. In the present study, we investigated the anti-proliferative effects of PGD using NSCLC cell lines. We evaluated the effects of PGD on proliferation, apoptosis and cell cycle arrest in A549 and H460 cells. PGD significantly induced apoptosis and nuclear condensation in both cell lines. Furthermore, PGD upregulated the cleavage of apoptotic proteins such as caspase-3, -9 and PARP. Additionally, treatment with PGD suppressed the expression of the IAP family of proteins including survivin, cIAP-1 and cIAP-2. Furthermore, PGD induced G0/G1-phase arrest in both cell lines. After treatment with PGD, the expression of TIMP-1, CDK2, cyclin A and cyclin E was reduced at the protein level. In addition, PGD blocked the PI3K/Akt pathway by inhibiting the phosphorylation of GSK3β, Akt and the expression of PI3K. Our results indicated that the anti-proliferative properties of PGD may result from the regulation of the PI3K/Akt pathway, which plays a critical role in cell survival and growth.

Globally, gastric cancer (GC) is one of the most common types of cancer and the third leading cause of cancer‑related death. In China, gastric and liver cancers have the highest mortality rates. Melatonin, also known as N-acetyl‑5-methoxytryptamine, is a hormone that is produced by the pineal gland in animals and regulates sleep and wakefulness. Melatonin has been shown to inhibit various carcinomas, including GC. There are many different hypotheses to explain the anticancer effects of melatonin, including stimulation of apoptosis, inhibition of cell growth, regulation of anticancer immunity, induction of free-radical scavenging, and the competitive inhibition of estrogen. However, the underlying mechanism by which these effects are elicited remains elusive. The aim of the present study was to investigate the effects of melatonin on human GC cells and determine the underlying molecular mechanism. We treated SGC-7901 GC cells with melatonin and analyzed the resulting protein changes using protein chip technology. Several proteins related to cell apoptosis and proliferation were identified and further tested in SGC-7901 GC cells. We found that melatonin induced cell cycle arrest and the downregulation of CDC25A, phospho-CDC25A (at Ser75), p21 (p21Cip1/p21Waf1) and phospho-p21 (at Thr145). Melatonin also induced upregulation of Bax, downregulation of Bcl-xL, an increase in cleaved caspase-9 level and activation of caspase-3, which confirmed the involvement of the mitochondria in melatonin‑induced apoptosis. Upstream regulators of the above proteins, MDM2, phospho-MDM2 (at Ser166) and AKT, phospho-AKT (at Thr308) were all attenuated by melatonin, which led to an increase in p53. The present study demonstrated that the oncostatic effects of melatonin on SGC-7901 GC cells are mediated via the blockade of the AKT/MDM2 intracellular pathway.

It is now widely accepted that the tumor microenvironment influences the fate of cancer cells and plays crucial roles in regulating tumor dormancy and chemoresistance. The standard cell culture system on plastic surfaces does not account for cell interactions with the extracellular matrix (ECM), and is thus a less reliable approach to analyze cellular activity ex vivo. In the present study, A549 lung cancer cells were cultured in a semi-solid growth substrate (Matrigel) to mimic the tumor microenvironment and to investigate the role played by ECM proteins, as well as to evaluate the mechanism of cell-ECM communication. A549 cells embedded in semi-solid Matrigel exhibited dormant cell characteristics, including decreased cell proliferation, migration and invasion rates, compared with the corresponding cells cultured on plastic plates. Exposure of A549 cells to Matrigel leads to resistance against conventional chemotherapeutic drugs (etoposide, paclitaxel, vinblastine, doxorubicin and 2-deoxy-D-glucose). Cell cycle distribution analysis indicated that a larger percentage of the cells embedded within semi-solid Matrigel was arrested in the G0/G1 phase. RT-qPCR analysis revealed that A549 cells cultured in semi-solid Matrigel exhibited a marked decrease in the expression levels of genes that are related to tumor progression and invasion (uPA, uPAR, MMP2, MMP7, MMP9 and CXCR4). The effects of altering various signaling pathways, such as p-ERK, p-Akt and p-STAT3, were evaluated, in order to assess whether these pathways could account for the observed responses of the cells. The inhibition of ERK1/2 and Akt activation using specific inhibitors induced G0/G1 arrest and drug resistance. These results demonstrated that Matrigel drove A549 cells into a drug-resistant dormancy state, most likely through inhibition of the ERK1/2 and PI3K/Akt pathways. Cell culture within semi-solid Matrigel offered a simple in vitro model for studying the mechanisms responsible for tumor dormancy and drug resistance. These studies may lead to therapeutic approaches that can eliminate dormant tumor cells and prevent disease recurrence.

The present study determined the anticancer activity and its mechanism of microRNA‑133b on cell proliferation of cisplatin-induced non-small cell lung cancer cells. The expression of microRNA-133b cisplatin‑induced non-small cell lung cancer (NSCLC) tissue was lower than that of para-carcinoma tissue in patients. Overall survival of higher expression in cisplatin-induced NSCLC patients was higher than that of lower expression in cisplatin‑induced NSCLC patients. Over-regulation of microRNA-133b inhibited cell proliferation and LDH activity, induced apoptosis and caspase-3 activity, suppressed the protein expression of EGFR, PI3K, p-Akt, p-JAK2 and p-STAT3, decreased cyclin D1 and increased Bax protein expression in cisplatin‑induced A549 cells. EGFR inhibitor (lapatinib) suppressed EGFR protein expression, inhibited cell proliferation and LDH activity, and induced apoptosis and caspase-3 activity in cisplatin-induced A549 cells by over-regulation of microRNA-133b. When EGFR protein expression was suppressed, PI3K, p-Akt, p-JAK2 and p-STAT3, decreased cyclin D1 and increased Bax protein expression in cisplatin-induced A549 cells by over-regulation of microRNA-133b. Altogether, our results indicated that over-regulation of microRNA-133b inhibits cell proliferation of cisplatin-induced NSCLC by PI3K/Akt and JAK2/STAT3 signaling pathway by targeting EGFR.

Gonadotropins, including luteinizing hormone (LH) and follicle stimulating hormone (FSH), are conducive to the growth of ovarian cancer based on the 'gonadotropin theory' and are regulated by gonadotropin-releasing hormone (GnRH). The present study was carried out to investigate the effect of goserelin, a GnRH agonist, on the apoptosis of epithelial ovarian cancer (EOC) cells and the underlying in vitro and in vivo mechanisms. Through flow cytometry, Hoechst staining and TUNEL staining, we demonstrated that goserelin promoted the apoptosis of EOC cells both in vitro and in vivo. Through human apoptosis gene PCR array, we verified that the promotion of EOC cell apoptosis by goserelin was linked to the upregulation of members of the tumor necrosis factor (TNF) and TNF receptor superfamilies, which have been identified as downstream targets of forkhead box O1 (FOXO1). Goserelin enhanced FOXO1 expression, and siRNA-mediated knockdown of FOXO1 abrogated the induction of apoptosis by goserelin. Moreover, goserelin decreased AKT activity, and FOXO1 upregulation by goserelin was dependent on the phosphatidylinositol 3-kinase (PI3K)/AKT pathway. In vivo, the expression of key factors in the PI3K/AKT/FOXO1 pathway was consistent with that observed in vitro. In conclusion, our data suggested that goserelin may promote EOC cell apoptosis by upregulating FOXO1 through the PI3K/AKT signaling pathway. We believe that GnRH agonists may be potential antitumor agents, and key factors in the PI3K/AKT-FOXO1 pathway may also be novel therapeutic targets for the treatment of EOC.

Cervical cancer is currently one of the major threats to women's health. The overexpression of heterogeneous nuclear ribonucleoprotein A2/B1 (hnRNP A2/B1) as the biomarker has been investigated in various cancers. In our previous study, we found that lobaplatin induced apoptosis and cell cycle arrest via downregulation of proteins including hnRNP A2/B1 in cervical cancer cells. However, the underlying relationship between hnRNP A2/B1 and cervical cancer remained largely unknown. hnRNP A2/B1 knock‑down in HeLa and CaSki cells was performed by shRNA transfection. The expression of hnRNP A2/B1 was detected by western blot and Quantitative Real‑time PCR. Cell proliferation, migration, invasion and the IC50 of lobaplatin and irinotecan were determined by MTT assay, Transwell assay, Plate colony formation assay and wound healing assay. Flow cytometry was perfomed to investigate cell apoptosis and the cell cycle. The expression of PI3K, AKT, p‑AKT, p21, p27, caspase‑3, cleaved caspase‑3 were revealed by western blot. Nude mouse xenograft model was undertaken with HeLa cells and the xenograft tumor tissue samples were analyzed for the expression of PCNA and Ki‑67 by immunohistochemistry and the cell morphology was evaluated by hematoxylin and eosin (H&E). Results revealed that hnRNP A2/B1 was successfully silenced in HeLa and CaSki cells. hnRNP A2/B1 knock‑down significantly induced the suppression of proliferation, migration, invasion and also enhancement of apoptosis and reduced the IC50 of lobaplatin and irinotecan. The expression of p21, p27 and cleaved caspase‑3 in shRNA group were significantly upregulated and the expression of p‑AKT was reduced both in vitro and in vivo. The results of immunohistochemistry showed that PCNA and Ki‑67 were significantly downregulated in vivo. The growth of nude mouse xenograft tumor was significantly reduced by hnRNP A2/B1 knock‑down. Taken together, these data indicate that inhibition of hnRNP A2/B1 in cervical cancer cells can inhibit cell proliferation and invasion, induce cell‑cycle arrestment and trigger apoptosis via PI3K/AKT signaling pathway. In addition, after silencing hnRNP A2/B1 can increase the sensitivity of cervical cancer cells to lobaplatin and irinotecan.

Licochalcone A (LicA) is a chalcone extracted from liquorice which has been used as a traditional Chinese medicine for many generations. Increased glucose consumption and glycolytic activity are important hallmarks of cancer cells, and hexokinase 2 (HK2) upregulation is a major contributor to the elevation of glycolysis. Recently, the antitumor activities of LicA have been reported in various cancers; however, its effect on tumor glycolysis in gastric cancer and the underlying mechanisms are completely unknown. In vitro, cell proliferation and clonogenic survival were substantially inhibited after LicA treatment. LicA reduced HK2 expression, and both glucose consumption and lactate production in gastric cancer cells were significantly suppressed. Mechanistic investigations revealed that multiple signaling pathways including Akt, ERK and NF‑κB were suppressed by LicA. Further studies demonstrated that the inhibition of glycolysis by LicA was mainly attributed to the blockade of the Akt signaling pathway, and the suppression of glycolysis was substantially attenuated when Akt was exogenously overexpressed. In addition to the role in the inhibition of glycolysis, reduction in HK2 was confirmed to be involved in the induction of cell apoptosis. The apoptosis induced by LicA was substantially impaired after HK2 overexpression in gastric cancer cells. The in vivo experiment showed that MKN45 xenograft growth was markedly delayed after LicA treatment and HK2 expression in LicA‑treated tissues was markedly decreased. All of these data demonstrated that blockade of the Akt/HK2 pathway was the underlying mechanism required for LicA to exert its biological activities in glycolysis inhibition and apoptosis induction.

miR-let-7a is the most widely studied miRNA, whose functions have been well-established by scientists in both carcinogenesis and progression of human cancer, including gastric cancer (GC). However, to date there is a lack of information concerning the relationship between miR-let-7a and cellular autophagy. Using western blotting and immunofluorescence, we determined that upregulation of miR-let-7a led to increased cellular autophagic level, whereas miR-let-7a suppression decreased autophagy activity in GC cells. To further elucidate the mechanisms underlying this, we screened potential targets of miR-let-7a using bioinformatics analyses, validated by a series of assays. Our results indicated that Rptor independent companion of mTOR complex 2 (Rictor) was a direct target of miR-let-7a. In addition, rescue experiments in vitro showed that miR-let-7a promoted cellular autophagic level by inhibiting Rictor expression in GC cells. Furthermore, as an upstream executor of Akt-mTOR signaling pathway, we found that Rictor elaborated its effect on autophagy by phosphorylating Akt and mTOR, and this regulatory process could also be mediated by miR-let-7a. Taken together, our results present a novel role for miR-let-7a in GC which modulates autophagy by targeting Rictor, following the regulation of Akt-mTOR signal pathway.

Increasing evidence indicates that long non‑coding RNAs (lncRNAs) play an important role in multiple biological processes including cell growth, differentiation, proliferation and invasion. Urothelial carcinoma associated 1 (UCA1) is a highly conserved nuclear ncRNA and a key regulator of cell proliferation and apoptosis in several types of cancers. However, its role in osteosarcoma progression is not well known. In the present study, we aimed to determine the biological role of UCA1 in osteosarcoma progression. RT‑qPCR analysis showed that UCA1 expression was significantly increased in osteosarcoma cell lines and promoted cell growth in osteosarcoma. We then sought to determine the mechanism underlying the upregulation of UCA1 in osteosarcoma. Luciferase reporter assay and chromatin immunoprecipitation assay suggested that lncRNA UCA1 was induced by HIF‑1α and HIF‑1α interacts with the HIF‑1α response element in the promoter region of UCA1. In addition, the gain- and loss-of-functional assay showed that HIF‑1α promoted osteosarcoma cell growth through inducing the UCA1 expression level. More importantly, Cignal Signal Transduction Reporter Array and western blot assay showed that lncRNA UCA1 inactivated the PTEN/AKT signaling pathway. Finally, we observed that HIF‑1α induced cell growth through the UCA1/PTEN/AKT signaling pathway. To conclude, our integrated approach demonstrates that UCA1 confers a tumor promoter function by promoting cell proliferation and silencing of the PTEN/AKT signaling pathway in osteosarcoma. Thus, UCA1 can serve as a promising therapeutic target for osteosarcoma patients.

Pulmonary carcinoma-associated proteins have emerged as crucial players in governing fundamental biological processes such as cell proliferation, apoptosis and metastasis in human cancers. Placenta-specific protein 1 (PLAC1) is a cancer-related protein, which is activated and upregulated in a variety of malignant tissues, including prostate cancer, gastric adenocarcinoma, colorectal, epithelial ovarian and breast cancer. However, its biological role and clinical significance in non-small cell lung cancer (NSCLC) development and progression are still unknown. In the present study, we found that PLAC1 was significantly upregulated in NSCLC tissues, and its expression level was associated with advanced pathological stage and it was also correlated with shorter progression-free survival of lung cancer patients. Furthermore, knockdown of PLAC1 expression by siRNA inhibited cell proliferation, induced apoptosis and impaired invasive ability in NSCLC cells partly via regulation of epithelial-mesenchymal transition (EMT)-related protein expression. Our findings present that increased PLAC1 could be identified as a negative prognostic biomarker in NSCLC and regulate cell proliferation and invasion. Thus, we conclusively demonstrated that PLAC1 plays a key role in NSCLC development and progression, which may provide novel insights on the function of tumor-related gene-driven tumorigenesis.