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Oral cancer (OC) has been attracted research attention in recent years as result of its high morbidity and mortality. Costunolide (CTD) possesses potential anticancer and bioactive abilities that have been confirmed in several types of cancers. However, its effects on oral cancer remain unclear. This study investigated the potential anticancer ability and underlying mechanisms of CTD in OC in vivo and in vitro. Cell viability and anchorage-independent colony formation assays were performed to examine the antigrowth effects of CTD on OC cells; assessments for migration and invasion of OC cells were conducted by transwell; Cell cycle and apoptosis were investigated by flow cytometry and verified by immunoblotting. The results revealed that CTD suppressed the proliferation, migration and invasion of oral cancer cells effectively and induced cell cycle arrest and apoptosis; regarding the mechanism, CTD bound to AKT directly by binding assay and repressed AKT activities through kinase assay, which thereby downregulating the downstream of AKT. Furthermore, CTD remarkably promotes the generation of reactive oxygen species by flow cytometry assay, leading to cell apoptosis. Notably, CTD strongly suppresses cell-derived xenograft OC tumor growth in an in vivo mouse model. In conclusion, our results suggested that costunolide might prevent progression of OC and promise to be a novel AKT inhibitor.

Shikonin, a natural product isolated from the roots of Lithospermum erythrorhizon, exhibits pharmacological effects against inflammation, ulcers, infections, and tumors. In the present study, we aimed to investigate the antitumor effects of shikonin on the human melanoma cell line, A375SM, and in an in vivo mouse xenograft model. We examined the anticancer effects of shikonin by in vitro experiments (MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, 4',6-diamidino-2-phenylindole (DAPI) stain, annexin V/ propidium iodide (PI) stain, and protein analysis of apoptosis and mitogen-activated protein kinase (MAPK) pathways). Further, the anticancer effect in vivo was confirmed through a xenograft model. Our results showed that shikonin inhibited the proliferation of melanoma cells in a dose-dependent manner. In addition, shikonin significantly increased nucleus and chromatin condensation and early/late apoptosis. Shikonin also increased the pro-apoptotic proteins and decreased the anti-apoptotic proteins. Additionally, shikonin was overexpressed in MAPK pathways. Investigation of the effects of shikonin in a mouse xenograft model not only showed decreased A375SM tumor volume but also increased apoptosis as determined by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay. Furthermore, pathologic changes were not observed in the liver and kidney of mice. Collectively, the study indicated that shikonin inhibited the proliferation of the human melanoma cells by inducing apoptosis, mediated by MAPK pathway and that it is a potential candidate for an anticancer drug against melanoma cancer., (© 2021 The Author(s).)

In this study, we investigated whether Quercetin has anti-cancer effects on A375SM and A375P human melanoma cells. Cell viability was assessed using an MTT assay. The proliferation of melanoma cells was measured by a wound-healing assay. Quercetin significantly decreased viability and proliferation of A375SM cells in a concentration-dependent manner. However, quercetin had no effect on A375P cells. DAPI staining showed increased chromatin condensation in a concentration-dependent manner, indicating apoptosis. Flow cytometric analysis indicated that quercetin suppressed the viability of A375SM cells by inducing apoptosis. Expression of quercetin-induced apoptosis proteins was investigated by Western blot analysis. Quercetin increased the expression of Bax, phospho-JNK, phospho-p38 and phospho-ERK1/2, cleaved poly-ADP ribose polymerase and decreased Bcl-2 in a concentration-dependent manner. We also investigated the in vivo tumor-growth inhibitory effect of quercetin. Quercetin (at 50 and 100 mg/kg) significantly decreased the A375SM tumor volume compared to the control group and increased apoptosis as assessed by the TUNEL assay. Immunohistochemistry staining revealed that the level of phosphor-JNK and phosphor-p38 increased in the quercetin-treated mice. These results indicate that quercetin inhibited the growth of A375SM melanoma cells through apoptosis and thus can be regarded as a new and effective chemo-preventive or therapeutic agent., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Purpose: ABT-263 is a potent BH3 mimetic that possesses anticancer potential against various types of cancer. In general, this potential is due to its high binding affinity to anti-apoptotic proteins in the Bcl-2 family that disrupt sequestration of pro-apoptotic proteins. In the present study, we sought to identify an alternative regulatory mechanism responsible for ABT-263-mediated anticancer activity in human oral cancer., Methods: We investigated the in vitro anti-cancer effects of ABT-263 using a trypan blue exclusion assay, Western blotting, DAPI staining, immunofluorescence staining, a live/dead assay, microarray-based expression profiling, and quantitative real-time PCR. In vivo anti-tumorigenic effects of ABT-263 were examined using a nude mouse tumor xenograft model, a TUNEL assay, and immunohistochemistry., Results: We found that ABT-263 suppressed viability and induced apoptosis in human oral cancer-derived cell lines HSC-3 and HSC-4. Subsequent microarray-based gene expression profiling revealed 55 differentially expressed genes in the ABT-263-treatead group, including 12 genes associated with "endoplasmic reticulum stress and apoptosis." Consistent with the microarray results, the mRNA expression levels of the top four genes (CHOP, TRB3, ASNS, and STC2) were found to be significantly increased. In addition, we found that ABT-263 considerably enhanced the expression levels of the C/EBP-homologous protein (CHOP) and its mRNA, resulting in apoptosis induction in four other human oral cancer-derived cell lines (MC-3, YD-15, HN22, and Ca9.22). Extending our in vitro findings, we found that ABT-263 reduced the growth of HSC-4 cells in vivo at a dosage of 100 mg/kg/day without any change in body weight. TUNEL-positive cells were also found to be increased in tumors of ABT-263-treated mice without any apparent histopathological changes in liver or kidney tissues., Conclusions: These results provide evidence that ABT-263 may serve as an effective therapeutic agent for the treatment of human oral cancer.

Background/aim: Piperine is a major pungent alkaloid present in black pepper (Piper nigrum L). This study investigated the potential anticancer effects of piperine on human melanoma cells and explored the potential pharmacological mechanisms in vitro and in vivo., Materials and Methods: Studies were performed using the MTT assay, 4',6-diamidino-2-phenylindole (DAPI) staining, western blotting, a xenograft model, the terminal deoxynucleotidyl transferase dUTP nick end labeling assay, and immunohistochemistry., Results: Piperine inhibited the growth of melanoma cells. Several apoptotic events were observed following treatment, as revealed by DAPI staining. Piperine increased the expression of BCL2-associated X, apoptosis regulator (BAX), cleaved poly(ADP-ribose)polymerase, cleaved caspase-9, phospho-c-Jun N-terminal kinase and phospho-p38, and reduced that of B-cell lymphoma 2 (BCL2), X-chromosome-linked inhibitor of apoptosis, and phospho-extracellular signal-regulated protein kinase (ERK1/2) in a concentration-dependent manner. Treatment of mice for 4 weeks with piperine inhibited tumor growth without apparent toxicity. Piperine increased the expression of apoptotic cells and cleaved-caspase-3 protein and reduced the expression of phospho-ERK1/2 protein in melanoma tumors., Conclusion: Piperine suppressed the growth of human melanoma cells by the induction of apoptosis via the inhibition of tumor growth of human melanoma cells and tumor xenograft models., (Copyright© 2019, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)

Marine triterpene glycosides are attractive candidates for the development of anticancer agents. Holotoxin A₁ is a triterpene glycoside found in the edible sea cucumber, Apostichopus (Stichopus) japonicus. We previously showed that cladoloside C₂, the 25(26)-dihydro derivative of holotoxin A₁ induced apoptosis in human leukemia cells by activating ceramide synthase 6. Thus, we hypothesized that holotoxin A₁, which is structurally similar to cladoloside C₂, might induce apoptosis in human leukemia cells through the same molecular mechanism. In this paper, we compared holotoxin A₁ and cladoloside C₂ for killing potency and mechanism of action. We found that holotoxin A₁ induced apoptosis more potently than cladoloside C₂. Moreover, holotoxin A₁-induced apoptosis in K562 cells by activating caspase-8 and caspase-3, but not by activating caspase-9. During holotoxin A₁-induced apoptosis, acid sphingomyelinase (SMase) and neutral SMase were activated in both K562 cells and human primary leukemia cells. Specifically inhibiting acid SMase and neutral SMаse with chemical inhibitors or siRNAs significantly inhibited holotoxin A₁-induced apoptosis. These results indicated that holotoxin A₁ might induce apoptosis by activating acid SMase and neutral SMase. In conclusion, holotoxin A₁ represents a potential anticancer agent for treating leukemia. Moreover, the aglycone structure of marine triterpene glycosides might affect the mechanism involved in inducing apoptosis., Competing Interests: The authors declare no potential conflicts of interest.

Non-small cell lung cancer (NSCLC) is the leading cause of cancer mortality worldwide. Despite progress in developing chemotherapeutics for the treatment of NSCLC, primary and secondary resistance limits therapeutic success. NSCLC cells exhibit multiple mutations in the epidermal growth factor receptor (EGFR), which cause aberrant activation of diverse cell signaling pathways. Therefore, suppression of the inappropriate amplification of EGFR downstream signaling cascades is considered to be a rational therapeutic and preventive strategy for the management of NSCLC. Our initial molecular target-oriented virtual screening revealed that the ginger components, including [6]-shogaol, [6]-paradol and [6]-gingerol, seem to be potential candidates for the prevention and treatment of NSCLC. Among the compounds, [6]-shogaol showed the greatest inhibitory effects on the NSCLC cell proliferation and anchorage-independent growth. [6]-Shogaol induced cell cycle arrest (G1 or G2/M) and apoptosis. Furthermore, [6]-shogaol inhibited Akt kinase activity, a downstream mediator of EGFR signaling, by binding with an allosteric site of Akt. In NCI-H1650 lung cancer cells, [6]-shogaol reduced the constitutive phosphorylation of signal transducer and activator of transcription-3 (STAT3) and decreased the expression of cyclin D1/3, which are target proteins in the Akt signaling pathway. The induction of apoptosis in NCI-H1650 cells by [6]-shogaol corresponded with the cleavage of caspase-3 and caspase-7. Moreover, intraperitoneal administration of [6]-shogaol inhibited the growth of NCI-H1650 cells as tumor xenografts in nude mice. [6]-Shogaol suppressed the expression of Ki-67, cyclin D1 and phosphorylated Akt and STAT3 and increased terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling-positivity in xenograft tumors. The current study clearly indicates that [6]-shogaol can be exploited for the prevention and/or treatment of NSCLC.

Radiation therapy is a widely used cancer treatment, but it causes side effects even when localized radiotherapy is used. Extensive apoptosis of microvascular endothelial cells of the lamina propria is the primary lesion initiating intestinal radiation damage after abdominal radiation therapy. Many in vitro studies suggest that angiopoietin-1 (Ang1) has potential therapeutic applications in enhancing endothelial cell survival. For in vivo use, we developed a soluble, stable, and potent Ang1 variant, COMP-Ang1. COMP-Ang1 is more potent than native Ang1 in phosphorylating the Tie2 receptor in lung endothelial cells in vivo. Interestingly, COMP-Ang1 administered i.v. was mainly localized to microvascular endothelial cells of the intestinal villi and lung but not to microvascular endothelial cells of the liver. In irradiated mice, i.v. COMP-Ang1 protected against radiation-induced apoptosis in microcapillary endothelial cells of the intestinal villi and prolonged survival. Thus, COMP-Ang1 could be used as a therapeutic protein for specific protection against endothelial cell injury.

Oral cancer remains the leading cause of death worldwide. Rhein is a natural compound extracted from the traditional Chinese herbal medicine rhubarb, which has demonstrated therapeutic effects in various cancers. However, the specific effects of rhein on oral cancer are still unclear. This study aimed to investigate the potential anticancer activity and underlying mechanisms of rhein in oral cancer cells. The antigrowth effect of rhein in oral cancer cells was estimated by cell proliferation, soft agar colony formation, migration, and invasion assay. The cell cycle and apoptosis were detected by flow cytometry. The underlying mechanism of rhein in oral cancer cells was explored by immunoblotting. The in vivo anticancer effect was evaluated by oral cancer xenografts. Rhein significantly inhibited oral cancer cell growth by inducing apoptosis and S-phase cell cycle arrest. Rhein inhibited oral cancer cell migration and invasion through the regulation of epithelial–mesenchymal transition-related proteins. Rhein induced reactive oxygen species (ROS) accumulation in oral cancer cells to inhibit the AKT/mTOR signaling pathway. Rhein exerted anticancer activity in vitro and in vivo by inducing oral cancer cell apoptosis and ROS via the AKT/mTOR signaling pathway in oral cancer. Rhein is a potential therapeutic drug for oral cancer treatment. [ABSTRACT FROM AUTHOR]

Targeted therapy at the molecular level is important for pancreatic cancer treatment. This study looked over the anticancer activity of Orostachys japonicus in a human pancreatic cancer cell line, PANC‐1. An ethyl acetate fraction containing quercetin, kaempferol, and flavonol glycosides from O. japonicus (OJE) exhibited significant anticancer activity against the PANC‐1. OJE activated caspase‐3, caspase‐8, and caspase‐9, leading to the induction of both intrinsic and extrinsic apoptosis pathways. It also inhibited cyclin D1, cyclin B1, and cyclin‐dependent kinase 4, representing cell cycle arrest at both G1/S and G2/M phases. In addition, OJE phosphorylated MAPKs such as p38, JNK, and ERK, which are important upstream signaling factors in apoptosis and arrest of cell cycle inducing system. In conclusion, OJE effectively exerted antipancreatic cancer activity via induction of apoptosis directed by both intrinsic and extrinsic pathways and arrest of cell cycle regulated at both G1/S and G2/M stages, which is activated by MAPKs, p38, JNK, and ERK. [ABSTRACT FROM AUTHOR]

Silymarin is a purified mixture of four isomeric flavonoids extracted from the seeds and fruit of the milk thistle plant, Silybum marianus (L.). Silymarin exhibits a wide variety of biological effects and is commonly used in traditional medicine. Therefore, the anticancer effects of silymarin on human breast cancer cells were investigated to determine its pharmacological mechanisms in vitro and in vivo. The viability and proliferation of MDA-MB- 231 and MCF-7 breast cancer cells were investigated using MTT and wound healing assays. Silymarin decreased the viability and proliferation of MDA-MB-231 and MCF-7 cells in a concentration-dependent manner. The number of apoptotic bodies, as shown by DAPI staining, was increased in a concentration-dependent manner, indicating that silymarin induces apoptosis. Additionally, changes in the expression levels of apoptosis-related proteins were demonstrated in human breast cancer cells using western blotting. Silymarin increased the levels of Bax, cleaved poly-ADP ribose polymerase, cleaved caspase-9 and phosphorylated (p-)JNK, and decreased the levels of Bcl-2, p-P38 and p-ERK1/2. Furthermore, the inhibitory effects of silymarin on MCF-7 tumor growth were investigated. In mice treated with silymarin for 3 weeks (25 and 50 mg/kg), MCF-7 tumor growth was inhibited without organ toxicity. In MCF-7 tumors, silymarin induced apoptosis and decreased p-ERK1/2 levels, as assessed using a TUNEL assay and immunohistochemistry. These results indicated that silymarin inhibited breast cancer cell proliferation both in vitro and in vivo by modulating the MAPK signaling pathway. Therefore, silymarin may potentially be used as a chemo-preventive or therapeutic agent. [ABSTRACT FROM AUTHOR]

Simple Summary: Colorectal cancer (CRC) is the fourth most common cancer and the second most common cause of cancer-related deaths globally. Rhein is a natural anthraquinone extract from rhubarb, which exhibits potent anticancer activity in various cancers. In this study, we show that rhein significantly inhibited the growth, migration, and invasion of CRC cells by directly binding to mTOR and inhibiting the mTOR signaling pathway. Rhein promotes mTOR degradation through the ubiquitin–proteasome pathway. In addition, rhein significantly suppressed tumor growth in a xenograft mouse model without obvious toxicity. Our results indicate that rhein is a promising anticancer agent that may be useful for the prevention and treatment of CRC. Colorectal cancer (CRC) is one of the leading causes of mortality and morbidity in the world. Rhein has demonstrated therapeutic effects in various cancer models. However, its effects and underlying mechanisms of action in CRC remain poorly understood. We investigated the potential anticancer activity and underlying mechanisms of rhein in CRC in vitro and in vivo. Cell viability and anchorage-independent colony formation assays were performed to examine the antigrowth effects of rhein on CRC cells. Wound-healing and Transwell assays were conducted to assess cell migration and invasion capacity. Cell cycle and apoptosis were investigated by flow cytometry and verified by immunoblotting. A tissue microarray was used to detect mTOR expression in CRC patient tissues. Gene overexpression and knockdown were done to analyze the function of mTOR in CRC. The anticancer effect of rhein in vivo was assessed in a CRC xenograft mouse model. The results show that rhein significantly inhibited CRC cell growth by inducing S-phase cell cycle arrest and apoptosis. Rhein inhibited CRC cell migration and invasion through the epithelial–mesenchymal transition (EMT) process. mTOR was highly expressed in CRC cancer tissues and cells. Overexpression of mTOR promoted cell growth, migration, and invasion, whereas mTOR knockdown diminished these phenomena in CRC cells in vitro. In addition, rhein directly targeted mTOR and inhibited the mTOR signaling pathway in CRC cells. Rhein promoted mTOR degradation through the ubiquitin-proteasome pathway. Intraperitoneal administration of rhein inhibited HCT116 xenograft tumor growth through the mTOR pathway. In conclusion, rhein exerts anticancer activity in vitro and in vivo by targeting mTOR and inhibiting the mTOR signaling pathway in CRC. Our results indicate that rhein is a potent anticancer agent that may be useful for the prevention and treatment of CRC. [ABSTRACT FROM AUTHOR]

Owing to the ineffectiveness of the currently used therapies against melanoma, there has been a shift in focus toward alternative therapies involving the use of natural compounds. This study assessed the anticancer effects of oleanolic acid (OA) and its ability to induce apoptosis in A375SM and A375P melanoma cells in vivo. Compared to the control group, viability of A375P and A375SM cells decreased following OA treatment. In OA-treated A375SM and A375P cells, 4′,6-diamidino-2-phenylindole staining showed an increase in the apoptotic body, and flow cytometry revealed increased number of apoptotic cells compared to that in the control group. OA-treated A375SM cells exhibited an increased expression of the apoptotic proteins, cleaved poly (ADP-ribose) polymerase (PARP) and B-cell lymphoma (Bcl)-2-associated X protein (Bax) as well as decreased expression of the antiapoptotic protein Bcl-2 compared to that in the control group. In OA-treated A375P cells, expression patterns of cleaved PARP and Bcl-2 were similar to those in OA-treated A375SM cells; however, no difference was reported in the expression of Bax compared to that in the control group. Additionally, OA-treated melanoma cells showed decreased expression of phospho-nuclear factor-κB (p–NF–κB), phospho-inhibitor of nuclear factor-κBα (p -IκBα), and phospho-IκB kinase αβ than that in the control group. Moreover, immunohistochemistry showed a comparatively decreased level of p–NF–κB in the OA-treated group than that in the control group. Xenograft analysis confirmed the in vivo anticancer effects of OA against A375SM cells. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay revealed an increased number of TUNEL-positive cells in the OA-treated group compared to that in the control group. In conclusion, the study results suggest that OA induces apoptosis of A375SM and A375P cells in vitro and apoptosis of A375SM cells in vivo. Furthermore, the in vitro and in vivo anticancer effects were mediated by the NF-κB pathway. • Oleanolic acid (OA) reduces the cell viability of A375SM and A375P melanoma cells. • OA induces apoptosis in A375SM and A375P melanoma cells. • OA regulates expression of apoptosis-related proteins in A375SM and A375P cells. • OA induced apoptosis through the NF-κB pathway. • OA holds significant potential as a natural anticancer agent for melanoma. [ABSTRACT FROM AUTHOR]