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Background Rapamycin has been known as an anti-cancer agent that affects different malignancies such as glioblastoma and prostate cancer. However, there are few studies concerning rapamycin effects on the cervical cancer cells. In this study, it was aimed to investigate the possible effect of rapamycin on a cervical cancer cell line and explored the possible mechanism(s) and pathway(s) for this agent. Materials and methods To do so, HeLa cells as cervical cancer cell line were used and treated with different concentrations of rapamycin under both normoxic and hypoxic conditions. Then, cell viability assays, Western blot, quantitative real-time polymerase chain reaction (QR-PCR), acridine orange and acridine orange/propidium iodide staining were performed to evaluate rapamycin effect on the mentioned cell line. Results The results showed that autophagy and apoptosis-related genes increased significantly in rapamycin-treated HeLa cells compared to controls. Moreover, cervical cancer cell death by rapamycin-induced autophagy in hypoxia was greater than normoxia compared with controls. In this study, it was showed that autophagy induction by rapamycin can mediate programmed cell death of cervical cancer cells, especially in hypoxic condition. Conclusion These findings provide a new evidence that rapamycin may inhibit hypoxic HeLa cell proliferation through the trigger of programmed cell death, facilitating the development of novel anti-cancer therapy.

Background and Aims HIF-1 is an important factor that play critical roles in metabolic and metastasis activity of cancer cells. HIF-1 activity can have regulated by TSGA10. Although decreased metastatic activity of cancer cells through TSGA10 inhibitory effect on HIF-1 have already been demonstrated, changes in cancer metabolism and its impact on metastasis in breast cancer is still not determined. So, we aimed to investigate TSGA10 overexpression effect on breast cancer metabolism as well as metastasis. Methods TSGA10 vector was designed and stable transfected into MCF-7 cells. The efficiency of transfection was assessed by Real-time PCR and western blot. After HIF-1 induction at high and low glucose conditions, cell proliferation, cell cycle profile, metabolic and metastasis activity of cells were assessed. Furthermore, biomarker expressions of ER, PR, HER2, Ki67 and E-cadherin in cancer cells were measured. Results Our results showed decrease of cell proliferation and cell cycle arrest in G2/M phase. Reduce expression of GLUT1, lactate production and reactive oxygen species (ROS) below their basal level indicated decreased metabolic activity. Furthermore, metastatic activity reduction was shown by decrease expression of different involve genes in metastasis, protelytic activity of MMOLP-2/9, carbonic anhydrase (CA) IX activity and increase of wound closure. Moreover, except for E-cadherin, expression of ER, PR, HER2 and Ki67 was declined in cells. Conclusion Our findings indicated that TSGA10 overexpression could decrease the metastatic and metabolic activity of cancer cells through its inhibitory effect on HIF-1 activity. Therefore, TSGA10 could be considered in the research for therapeutic candidates in cancer.

Numerous antitumor therapies have been developed based on the differences in cells' metabolisms. Regarding the important role of arginine (Arg) in the regulation of multiple metabolic and signaling pathways, its deprivation has been proposed as a good strategy for tumor regression in tumors with defected Arg metabolic enzymes like argininosuccinate synthase 1 (ASS1). However, modulatory effect of Arg on various cancers is also a controversial issue. Therefore, this review article intends to address some of the challenges faced by Arg deprivation method as well as Arg administration for cancer therapy.

Introduction: Organisms are exposed to oxygen deprivation (Hypoxia) in various physiological and pathological conditions. There are different conserve evolutionary responses to counterview with this stress that primary transcriptional response to stress related to hypoxia is interceded by hypoxia-inducible factor (HIF-1) in mammals. This factor can regulate different genes that have essential roles in adaptation to this condition. In this review, the role of this factor in physiological and pathological conditions under hypoxic condition has been evaluated after examining structural features and regulation characteristics of HIF-1. Methods: First, articles related to the keywords of hypoxia and HIF-1 (from 1991-2016) were searched from valid databases such as Springer Link, Google Scholar, PubMed and Science direct. Then, the articles correlated with hypoxia, HIF-1 and their roles in physiological and pathological conditions (120 articles) were searched and just 64 articles were selected for this study. Result: According to studies, there are different genes in cells and organs that can be regulated by HIF-1. Activation of genes expression by this protein occurs through its linkage to cis-acting of 50 base pair hypoxia response element (HRE) region located in their promotor and enhancer. Depending on circumstances, activation of these genes can be beneficial or harmful. Conclusion: Activation of different genes in hypoxia by HIF-1 has different effects on physiological and pathological conditions. Therefore, HIF-1, as a hypoxia-inducible factor in hypoxic conditions, plays an essential role in the adaptation of cells and organs to changes related to the presence of oxygen.

Background: Testis-specific gene antigen (TSGA10) mainly involves in spermatogenesis and embryogenesis. In the new defined roles, being a tumor suppressor agent or a cancer/testis antigen (CTA) is still unclear for this protein. The current study aimed to examine exact role of TSGA10 as a tumor suppressor or CTA in breast cancer and evaluate the role of microenvironment on its expression. Methods: This study evaluated the expression of TSGA10 and hypoxia-inducible factor 1α (HIF-1α) in two different breast cancer cell lines (MCF-7 and MDA-MB23) as well as their control (MCF10A) using real-time PCR. Moreover, expression of the mentioned genes evaluated in samples obtained from tumoral tissues with two types of controls: paired (tumor-free margin) and unpaired (healthy individuals). Also, in order to asses TSGA10 levels in the tumoral tissues, western blotting was performed. Furthermore, to evaluate the role epigenetic changes on TSGA10 expression, breast cancer cell lines were treated with a histone deacetylase inhibitor (HDACI) as well as H2O2 for oxidative stress induction. Results: The current study evaluated 36 patients diagnosed with breast cancer as well as 10 healthy controls. According to the results, it was shown that 35 (97.7%) and 1 (2.8%) of patients were diagnosed with ductal and lobular carcinomas respectively. The TSGA10 levels in the tumoral samples showed 1.38±0.014-fold decrease and 1.41±0.127-fold increase compared with their paired (PTSGA10 expression in MCF-7 and MDA-MB23 cells had 4.9±0.283 and 4.21±0.163 folds of decrease in normoxic and 4.7±.0.283 and 7.1±0.141 folds of expression reduction in hypoxic condition respectively (all PHIF-1α expression was up-regulated in both normoxic (PTSGA10 expression increased up to 7.39±0.156 folds in MCF-7 cells after HDACI treatment (all PTSGA10 expression (all PConclusion: Results of current study showed that TSGA10 seems to be tumor suppressor, however, further studies are necessary.

Reducing the adverse effects of chemotherapy on normal cells such as endothelial cells is a determinant factor of treatment success especially in pregnant women. In this regard, modulatory effect of L-arginine on various cancers is still a controversial topic in cancer therapy. So, this study aimed to compare the effect of L-arginine treatment alone and in combination with 5-fluorouracil (5-FU) on the survival and angiogenesis of primary human umbilical vein endothelial cells (HUVECs) and the breast cancer cell line of MDA-MB-468. Combinations of L-arginine and 5-FU increased cell survival in HUVECs but induced cell death in MDA-MB-468 cells. Nitric oxide assay showed an increase of this molecule in both cell lines. Assessments of metabolic changes as well as molecular docking indicated a decrease in glycolytic activity of cancer cells but not normal cells. Angiogenesis induction in HUVECs was confirmed through VEGF and MMP-2,9 up-regulated gene expressions. However, a down-regulation of the above-mentioned genes expression was observed in MDA-MB-468. Furthermore, an in vivo increased angiogenesis and decreased embryo toxicity was observed in combination treatment. Altogether, these findings clearly suggest that L-arginine inhibits cell death induced by 5-FU in HUVECs through attenuating the adverse effects of 5-FU, while it does not do so in breast cancer cells.

Background HIF-1 stability and activity is known to be regulated by different factors such as TSGA10 and H2AX. Although TSGA10 and H2AX effects on the HIF-1 have already been demonstrated, changes in HIF-1 activity in the presence of both the mentioned factors are still not determined. So, in the current study we aimed to investigate HIF-1 activity by evaluation of metastasis and metabolism of breast cancer cells, in the presence of H2AX and TSGA10 over-expression. Methods TSGA10 vector was designed and stably transfected into MCF-7 cells. The efficiency of transfection was assessed by real-time PCR and western blot. After HIF-1 induction at high and low glucose conditions, cell proliferation, cell cycle profile, metabolic and metastasis activity of cells were assessed. Furthermore, biomarker expressions of ER, PR, HER2, Ki67, and E-cadherin in cancer cells were measured. Docking analysis was done for comparison and approval of TSGA10 and H2AX binding affinity to HIF-1. Results Increased expression of TSGA10 decrease the metastasis and metabolism activity in MCF-7. Docking analysis revealed that the binding affinity of TSGA10 to HIF-1 was greater than that of H2AX which confirms the earlier mentioned results. Conclusion Our findings indicated that TSGA10 over-expression decreased metastasis and metabolic activity of cancer cells through inhibiting H2AX impact on HIF-1 activity. Therefore, TSGA10 could be considered in the research for therapeutic candidates in cancer.

Background L-Arginine effectiveness cancer therapy is a matter of controversy. L-Arginine is a substrate for different metabolites influencing cancer cells. Arginase and nitric oxide synthase (NOS) are two important enzymes in the L-Arginine metabolic pathway. Nitric oxide (NO) is produced by NOS and the main products of arginase activity are polyamines. NO can decrease cancer cells viability dependent on its concentration but, polyamines shown to promote cancer cell growth/metastasis. Due to Arginase and NOS competition over L-Arginine binding, inhibition of arginase activity seems to increase NOS activity as well as NO production. Thus, the aim of the present study is to affect L-Arginine metabolic pathway through L-Lysine induced arginase inhibition in MDA-MB-231 and MDA-MB-468 Methods MDA-MB-231 and MDA-MB-468 were used as triple negative breast cancer cells with different arginase activity. Both cell lines were treated with different concentrations of L-Arginine and L-Lysine. Cell viability was assessed by MTT assay 24 and 48h after treatment. Arginase activity, ROS level and NO concentration was examined. Cell cycle was assessed using flowcytometry. Real-time PCR was performed to assess apoptotic and metabolic genes expression Results Our results indicated that cell viability and arginase activity were decreased in MDA-MB-468 with high arginase level more than MDA-MB-231 and studying the cell cycle also showed G2/M arrest in both cell lines following combination treatment with L-Lysine with L-Arginine. L-Lysine treatment resulted in increased apoptotic genes and decreased metabolic related genes expression in both cell lines Conclusion Altogether, our findings indicated that alternation in L-Arginine metabolic pathway using L-Lysine causes higher NO concentration which consequently increases cell death in triple negative breast cancer cells with different arginase level, which in turn can increase L-Arginine effect on cell lines with higher arginase activity

Background Breast cancer is the first cause of death among Women. Chemoresistance is believed to be responsible for most of the mortalities, thus using new therapeutic strategies are needed. Autophagy has been shown as a critical player in cancer cells response to chemotherapeutic drugs such as doxorubicin. However, autophagy effect on cancer cell can be viewed as a pro-death or a pro-survival role. Thus, increase or decrease of this process in cells relative to its baseline can induce cancer cell death. Thus, we investigated if L-Lysine can increase doxorubicin effectiveness in combination therapy through autophagy modulation. Methods MDA-MB-231 and MDA-MB-468 were used as two breast cancer cell lines. Cells were treated with various concentrations of doxorubicin and L-Lysine. Cell viability was assessed using MTT assay 24 and 48h after treatment. ROS and NO level was examined and the expression of various autophagy and apoptosis related proteins/genes were evaluated with western blotting and real-time PCR respectively. Results L-Lysine increased cytotoxicity effect of doxorubicin in both MDA-MB-231 and MDA-MB-468 by autophagy enhancement. L-Lysine reduced cell viability and increased apoptosis in combination with doxorubicin. Real-time PCR analysis indicated that the combination of these two drugs resulted in increased autophagy as well as apoptosis-related genes. Moreover, reactive oxygen species (ROS) and nitric oxide (NO) production increased 30min after treatment with both drugs. However, the amount of these molecules decreased after 24h which can be results of autophagy induction. These results were further confirmed at protein levels of LC-3 and mTOR by western blotting. Conclusion Our findings indicated that L-Lysine can reduce the resistance to doxorubicin in triple negative breast cancer cells, MDA-MB-231 and MDA-MB-468. Therefore combination therapy with L-Lysine and doxorubicin could be consider an effective strategy in breast cancer therapy.

Chemoresistance in breast cancer is a major obstacle, especially in p53 mutation types. The aim of this study was to evaluate if a combination therapy of l-arginine with 5-fluorouracil (5-FU) can alter the effect of this chemotherapy drug on breast cancer cells. The study was performed on BT-20 and MCF-7 cell lines. The effects of l-arginine alone and in combination with 5-FU were investigated on cell viability, apoptosis and nitric oxide (NO) production. Drugs effects on the cellular energetic metabolism were investigated through the lactate production and glucose-6-phosphate dehydrogenase (G6PD) activity assay. Migration and invasion of treated cells were assessed. Real- time PCR was used for analyzing the changes in the expression level of CXCL12 and CXCR4 as two important genes involved in migration and metastasis of breast cancer cells. l-arginine increased 5-FU effect on BT-20 and MCF-7 cell lines by reducing cell viability and increasing apoptosis and NO production. Lactate production and G6PD activity assays showed that cellular energetic metabolism of both cells was altered in favor of cell death. Moreover, l-arginine decreased the metastatic activity of both cells which was confirmed through migration, invasion and gene expression results performed for both cell lines. However, drugs effect on MCF-7 (p53 wild-type) was greater than that of BT-20 (p53 mutation) in all sets of experiments. Our findings indicated that l-arginine increased the anticancer effect of 5-FU in BT-20 and MCF-7 cell lines. So, combination therapy with l-arginine and 5-FU could be considered as an effective strategy in breast cancer therapy.