L-lysine Increases the Anticancer Effect of Doxorubicin in Breast Cancer by Inducing ROS-Dependent Autophagy.

BACKGROUND: Doxorubicin (DOX) is a chemotherapy drug that is widely used in cancer therapy, especially in Triple-Negative Breast Cancer (TNBC) patients. Nevertheless, cytoprotective autophagy induction by DOX limits its cytotoxic effect and drug resistance induction in patients. Therefore, finding a new way is essential for increasing the effectiveness of this drug for cancer treatment. OBJECTIVE: This study aimed to investigate the effect of L-lysine on DOX cytotoxicity, probably through autophagy modulation in TNBC cell lines. METHODS: We used two TNBC cell lines, MDA-MB-231 and MDA-MB-468, with various levels of autophagy activity. Cell viability after treatment with L-lysine alone and in combination therapy was evaluated by MTT assay. Reactive Oxygen Species (ROS), nitric oxide (NO) concentration, and arginase activity were assessed using flow cytometric analysis, Griess reaction, and arginase activity assay kit, respectively. Real-time PCR and western blot analysis were used to evaluate the L-lysine effect on the autophagy-related genes and protein expression. Cell cycle profile and apoptotic assay were performed using flow cytometric analysis. RESULTS: The obtained data indicated that L-lysine in both concentrations of 24 and 32 mM increased the autophagy flux and enhanced the DOX cytotoxicity, especially in MDA-MB-231, which demonstrated higher autophagy activity than MDA-MB-468, by inducing ROS and NO production. Furthermore, L-lysine induced G2/M arrest autophagy cell death, while significant apoptotic changes were not observed. CONCLUSION: These findings suggest that L-lysine can increase DOX cytotoxicity through autophagy modulation. Thus, L-lysine, in combination with DOX, may facilitate the development of novel adjunct therapy for cancer.

Engineering of a decellularized bovine skin coated with antibiotics-loaded electrospun fibers with synergistic antibacterial activity for the treatment of infectious wounds.

An ideal antibacterial wound dressing with strong antibacterial behavior versus highly drug-resistant bacteria and great wound-healing capacity is still being developed. There is a clinical requirement to progress the current clinical cares that fail to fully restore the skin structure due to post-wound infections. Here, we aim to introduce a novel two-layer wound dressing using decellularized bovine skin (DBS) tissue and antibacterial nanofibers to design a bioactive scaffold with bio-mimicking the native extracellular matrix of both dermis and epidermis. For this purpose, polyvinyl alcohol (PVA)/chitosan (CS) solution was loaded with antibiotics (colistin and meropenem) and electrospun on the surface of the DBS scaffold to fabricate a two-layer antibacterial wound dressing (DBS-PVA/CS/Abs). In detail, the characterization of the fabricated scaffold was conducted using biomechanical, biological, and antibacterial assays. Based on the results, the fabricated scaffold revealed a homogenous three-dimensional microstructure with a connected pore network, a high porosity and swelling ratio, and favorable mechanical properties. In addition, according to the cell culture result, our fabricated two-layer scaffold surface had a good interaction with fibroblast cells and provided an excellent substrate for cell proliferation and attachment. The antibacterial assay revealed a strong antibacterial activity of DBS-PVA/CS/Abs against both standard strain and multidrug-resistant clinical isolates of Acinetobacter baumannii, Pseudomonas aeruginosa, and Escherichia coli. Our bilayer antibacterial wound dressing is strongly suggested as an admirable wound dressing for the management of infectious skin injuries and now promises to advance with preclinical and clinical research.

Hypoxia: A key feature of COVID-19 launching activation of HIF-1 and cytokine storm.

COVID-19, disease caused by the new coronavirus, SARS-CoV-2, appeared in the end of 2019 and was rapidly spread in most countries. This respiratory virus has different symptoms from moderate to severe, and results in lung pneumonia following acute respiratory distress syndrome (ARDS) and patient's death in severe cases. ARDS is a severe form of acute lung injury that is caused by high inflammatory response of the innate immunity cells. Hypoxia is the common feature in the inflammatory sites with having various impacts on this condition by induction of some factors such as hypoxia inducible factor-1α (HIF-1α). HIF-1α regulates some important cellular processes including cell proliferation, metabolism and angiogenesis. Furthermore, this factor is activated during the immune responses and plays important roles in the inflammation site by inducing pro-inflammatory cytokines production through immune cells. So, in this study the possible effect of the HIF-1α on the COVID-19 pathogenesis with emphasizes on its role on innate immunity response has been discussed.

Regenerative Medicine and Angiogenesis; Challenges and Opportunities.

Blood vessel development is one of the most prominent steps in regenerative medicine due to the restoration of blood flow to the ischemic tissues and providing the rapid vascularization in clinical-sized tissue-engineered grafts. However, currently tissue engineering technique is restricted because of the inadequate in vitro/in vivo tissue vascularization. Some challenges like as transportation in large scale, distribution of the nutrients and poor oxygen diffusion limit the progression of vessels in smaller than clinically relevant dimensions as well in vivo integration. In this regard, the scholars attempted to promote the vascularization process relied on the stem cells (SCs), growth factors as well as exosomes and interactions of biomaterials with all of them to enable the emergence of ideal microenvironment which is needed for treatment of unhealthy organs or tissue regeneration and formation of new blood vessels. Thus, in the present review we aim to describe these approaches, advances, obstacles and opportunities as well as their application in regeneration of heart as a prominent angiogenesis-dependent organ.

Rapamycin Reduces Cervical Cancer Cells Viability in Hypoxic Condition: Investigation of the Role of Autophagy and Apoptosis.

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.

TSGA10 Over Expression Decreases Metastasic and Metabolic Activity by Inhibiting HIF-1 in Breast Cancer Cells.

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.

L-arginine/5-fluorouracil combination treatment approaches cells selectively: Rescuing endothelial cells while killing MDA-MB-468 breast cancer cells.

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.

Arginine: Challenges and opportunities of this two-faced molecule in cancer therapy.

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.

l-arginine alters the effect of 5-fluorouracil on breast cancer cells in favor of apoptosis.

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.