Metformin and neoplasia: implications and indications

Anticarcinogenic Effects of Gold Nanoparticles and Metformin Against MCF-7 and A549 Cells

Metformin is commonly prescribed to people with diabetes. Metformin has been shown in previous studies to be able to prevent the growth of cancer cells. This study aims to investigate the effects of metformin and gold nanoparticles in MCF7 breast cancer and A549 lung cell lines. The effects of metformin and gold nanoparticles on MCF7 breast cancer and A549 lung cells were determined on cells grown in 24 h cell culture. MCF-7 and A549 cells were incubated for 24 h with the treatment of escalating molar concentrations of ifosfamide. The MTT assay was used to determine the cytotoxicity of metformin toward MCF7 and A549 cell lines. The expression of Bax, BCL2, PI3K, Akt3, mTOR, Hsp60, Hsp70, and TNF-α was measured by RT-PCR. Metformin and gold nanoparticles inhibited the proliferation of MCF-7 and A549 cells in a dose and time-dependent manner with an IC50 value of 5 µM and 10 µg/mL. RT-PCR assays showed ifosfamide + metformin + gold nanoparticles significantly reduced the expression of BCL2, PI3K, Akt3, mTOR, Hsp60 and Hsp70 and increased the expression of TNF-α and Bax. The findings obtained in this study suggest that further studies should be conducted, and metformin and gold nanoparticles can be used in breast cancer and lung cancer treatments.

A novel action of insulin sensitizing drug as a potential promotor of preovulatory follicles, ovulation rate and prolificacy in sheep

The effect of the insulin-sensitizing drug metformin on preovulatory follicle (POF) number, ovulation rate, fetal rate and prolificacy was studied in forty-six cyclic Malpura ewes. After estrus synchronization, the ewes were equally divided into two groups (n = 23). The treatment group (MET) received a daily oral dose of metformin at a rate of 500 mg/animal for approximately 12 weeks, spanning five estrous cycles, as against untreated control (CON). All the ewes were bred to proven rams at the end of treatment. Ovarian ultrasound scans were performed at each estrus and day 9 of each cycle to assess the number and diameter of POFs and corpora lutea (CL), respectively. A comprehensive assessment of circulating hormones including, estradiol, progesterone, androstenedione, and insulin as well as metabolic indicators such as glucose, and lipid profile parameters was performed. At the end of treatment on the day of estrus (E5D0), the treatment showed a stimulatory effect on follicular development with a 53.2% (P < 0.001) increase in the number of POFs. It also increased the ovulation rate by 67.4% (P < 0.01), with a higher proportion (χ2df1 = 10.7, P < 0.001) of ewes in the MET group having multiple ovulations compared to the CON group (82.6 vs. 30.4%). With 1.48 ± 0.12 prolificacy rate in MET ewes, the proportion of ewes giving birth to multiple lambs was 2.9-fold higher than in the CON group. Plasma estradiol, insulin, glucose, total cholesterol, and LDL-cholesterol concentrations were lower (P < 0.05) in the MET ewes than in the CON. The results of the present study indicate that metformin can increase the number of POF, ovulation rate, fetal rate and prolificacy in ewes, while reducing the plasma estradiol, insulin, glucose and cholesterol in MET ewes.

Applications of Metformin in Dentistry-A review

Metformin is a versatile drug with numerous medical uses. It is known primarily as an anti-hyperglycemic drug that has become the main oral blood-glucose-lowering medication for managing type 2 diabetes mellitus globally. Its use has been reported in a variety of oral conditions and dentistry in general. Recent clinical trials have indicated the effectiveness of adjunct topical application of metformin in improving the periodontal parameters of patients with diabetes and periodontitis. Additionally, studies have suggested that metformin stimulates odontogenic differentiation and mineral synthesis of stem cells in the tooth pulp. Metformin also stimulates osteoblast proliferation, decreases osteoclast activity and exerts regenerative effects on periodontal bone, thus making it a viable candidate for periodontal regeneration. Metformin monotherapy significantly enhances osseointegration of endosseous implants and has been reported to have anti-cancer effects on oral squamous cell carcinoma by impeding tumor progression. Animal studies have indicated that metformin improves orthodontic tooth movement and resists orthodontic appliance corrosion. This narrative review aims to provide a current summary of research highlighting the prospective uses of metformin in dentistry.

Recent Advances (2015-2020) in Drug Discovery for Attenuation of Pulmonary Fibrosis and COPD

A condition of scarring of lung tissue due to a wide range of causes (such as environmental pollution, cigarette smoking (CS), lung diseases, some medications, etc.) has been reported as pulmonary fibrosis (PF). This has become a serious problem all over the world due to the lack of efficient drugs for treatment or cure. To date, no drug has been designed that could inhibit fibrosis. However, few medications have been reported to reduce the rate of fibrosis. Meanwhile, ongoing research indicates pulmonary fibrosis can be treated in its initial stages when symptoms are mild. Here, an attempt is made to summarize the recent studies on the effects of various chemical drugs that attenuate PF and increase patients' quality of life. The review is classified based on the nature of the drug molecules, e.g., natural/biomolecule-based, synthetic-molecule-based PF inhibitors, etc. Here, the mechanisms through which the drug molecules attenuate PF are discussed. It is shown that inhibitory molecules can significantly decrease the TGF-β1, profibrotic factors, proteins responsible for inflammation, pro-fibrogenic cytokines, etc., thereby ameliorating the progress of PF. This review may be useful in designing better drugs that could reduce the fibrosis process drastically or even cure the disease to some extent.

Circulating selenoprotein P levels predict glucose-lowering and insulinotropic effects of metformin, but not alogliptin: A post-hoc analysis

AIMS/INTRODUCTION

Selenoprotein P (SeP; encoded by SEPP1 in humans) is a hepatokine that causes impaired insulin secretion and insulin resistance. Metformin downregulates SELENOP promoter activity through an adenosine monophosphate-activated kinase-forkhead box protein O3a pathway in hepatocytes. This study aimed to test our hypothesis that circulating SeP levels are associated with the glucose-lowering effect of metformin in humans.

MATERIALS AND METHODS

A total of 84 participants with poorly controlled type 2 diabetes were randomly assigned to receive metformin (1,000 mg, twice daily) or a dipeptidyl peptidase-4 inhibitor, alogliptin (25 mg, once daily) for 12 weeks. We tested metformin and alogliptin on SeP levels and factors associated therewith as a post-hoc analysis.

RESULTS

Both metformin and aloglipitin did not change the SeP levels. Although metformin significantly increased the insulin secretory index secretory units of islets in transplantation only in participants with higher baseline SeP (>3.87), both agents similarly reduced fasting plasma glucose and glycated hemoglobin. SeP levels at baseline were correlated negatively with changes in SeP (r = -0.484, P = 0.004) and fasting plasma glucose (r = -0.433, P = 0.011), and positively with changes in C-peptide immunoreactivity (r = 0.420, P = 0.017) and secretory units of islets in transplantation (r = 0.388, P = 0.028) in the metformin, but not alogliptin, group.

CONCLUSIONS

Higher baseline levels of SeP significantly predicted metformin-mediated, but not alogliptin-mediated, glucose-lowering and insulinotropic effects. Serum SeP levels might be a novel biomarker for predicting the outcomes of metformin therapy, which might be helpful in tailoring diabetes medication.

Metformin in the prevention of colorectal cancer with diabetes mellitus

The purpose of the review is to present an analysis of current literature data on the prospects of using the oncoprotective effect of metformin in colorectal cancer. Metformin is a drug with a long history, it is a first-line drug for the treatment of type 2 diabetes mellitus (DM2), as well as the most commonly prescribed drug worldwide. Modern researches show that in addition to its role in glucose control, metformin can reduce the risk and mortality from some malignancies and improve the response of patients with DM2 to certain types of cancer treatment. Accumulated data indicate that metformin could be a candidate drug for drug prevention of colorectal cancer.

Association of Tumor Pathological Response with the Use of Metformin During Neoadjuvant Chemoradiotherapy in Rectal and Esophageal/Gastroesophageal Cancer Patients: a Systematic Review and Meta-analysis

PURPOSE

Metformin has been reported to be associated with improved cancer prognosis when used in combination with chemotherapy and/or radiotherapy. In this study, we present a systematic review and meta-analyses of studies evaluating the association of tumor pathological response with the use of metformin during neoadjuvant chemoradiotherapy (NACRT) in rectal and esophageal/gastroesophageal cancer patients.

METHODS

We systematically searched databases for articles that compared concurrent metformin use with no metformin use in cancer patients treated with NACRT following the PRISMA 2020. The design and quality of the collected studies were reviewed, and meta-analyses were performed on the pathologic complete response (pCR) rate, tumor regression grade (TRG), T factor downstaging, and N factor downstaging.

RESULTS

Three databases were searched, and 220 papers were screened. Five retrospective cohort study papers were eligible for the meta-analysis, with a total of 2041 patients. The included papers contained only rectal and esophageal/gastroesophageal cancers. In the metformin group, the pCR rate was 26% [20-32%], and metformin was associated with the pCR rate (odds ratio [OR] = 0.51 [0.34-0.76], p < 0.01). Meta-regression analysis of the pCR rate showed a positive correlation with adenocarcinoma (coefficient = 0.13 [0.02-0.25], p = 0.03) and fluoropyrimidine anticancer drug use (coefficient = 0.01 [0.001-0.02], p = 0.03).

CONCLUSIONS

The results suggest that metformin is associated with pCR rate when used in combination with NACRT. The association of metformin and pCR rate in combination with fluoropyrimidine anticancer drugs was observed mostly for adenocarcinoma patients.

ABCA8 inhibits breast cancer cell proliferation by regulating the AMP activated protein kinase/mammalian target of rapamycin signaling pathway

ATP-binding cassette (ABC) subfamily A member 8 (ABCA8) has been reported to play a vital role in cancer development. Our study aimed to explore the role and the molecular mechanism of ABCA8 in breast cancer (BC) progression. GSE65194, GSE15852, and GSE45827 datasets were used to identify differentially expressed genes (DEGs) in BC. The diagnosis and prognosis value were determined using ROC curve analysis and Kaplan-Meier plotter, respectively. The relationship between ABCA8 expression and clinicopathological features in BC was analyzed by TCGA. Co-expressed genes of ABCA8 in BC were screened out through GEPIA and subjected to KEGG pathway enrichment analysis. Cell proliferation was evaluated by CCK-8 and EdU incorporation assays. Proliferating cell nuclear antigen (PCNA) expression and the changes of the AMP activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway were measured by western blot analysis. Totally 4 overlapping DEGs were identified and all reduced in BC samples. ABCA8 with high diagnostic and prognostic values was selected for further exploration. Low ABCA8 expression was correlated with clinicopathological features in BC patients. ABCA8 overexpression inhibited BC cell proliferation. The top 20 co-expressed genes of ABCA8 were identified by GEPIA and significantly enriched in AMPK signaling pathway. Inhibition of AMPK/mTOR pathway reversed the suppressive effect of ABCA8 on BC cell growth. These results suggested that ABCA8 overexpression repressed BC cell proliferation through regulating the AMPK/mTOR signaling pathway.

In vivo and in vitro studies evaluating the chemopreventive effect of metformin on the aryl hydrocarbon receptor-mediated breast carcinogenesis

Metformin (MET) is a clinically used anti-hyperglycemic agent that shows activities against chemically-induced animal models of cancer. A study from our laboratory showed that MET protectes against 7, 12-dimethylbenz[a]anthracene (DMBA)-induced carcinogenesis in vitro human non-cancerous epithelial breast cells (MCF10A) via activation of the aryl hydrocarbon receptor (AhR). However, it is unclear whether MET can prevent the initiation of breast carcinogenesis in an in vivo rat model of AhR-induced breast carcinogenesis. Therefore, the main aims of this study are to examine the effect of MET on protecting against rat breast carcinogenesis induced by DMBA and to explore whether this effect is medicated through the AhR pathway. In this study, treatment of female rats with DMBA initiated breast carcinogenesis though inhibiting apoptosis and tumor suppressor genes while inducing oxidative DNA damage and cell cycle proliferative markers. This effect was associated with activation of AhR and its downstream target genes; cytochrome P4501A1 (CYP1A1) and CYP1B1. Importantly, MET treatment protected against DMBA-induced breast carcinogenesis by restoring DMBA effects on apoptosis, tumor suppressor genes, DNA damage, and cell proliferation. Mechanistically using in vitro human breast cancer MCF-7 cells, MET inhibited breast cancer stem cells spheroids formation and development by DMBA, which was accompanied by a proportional inhibition in CYP1A1 gene expression. In conclusion, the study reports evidence that MET is an effective chemopreventive therapy for breast cancer by inhibiting the activation of CYP1A1/CYP1B1 pathway in vivo rat model.

The multifaceted roles of mitochondria at the crossroads of cell life and death in cancer

Mitochondria are the cytoplasmic organelles mostly known as the "electric engine" of the cells; however, they also play pivotal roles in different biological processes, such as cell growth/apoptosis, Ca²⁺ and redox homeostasis, and cell stemness. In cancer cells, mitochondria undergo peculiar functional and structural dynamics involved in the survival/death fate of the cell. Cancer cells use glycolysis to support macromolecular biosynthesis and energy production ("Warburg effect"); however, mitochondrial OXPHOS has been shown to be still active during carcinogenesis and even exacerbated in drug-resistant and stem cancer cells. This metabolic rewiring is associated with mutations in genes encoding mitochondrial metabolic enzymes ("oncometabolites"), alterations of ROS production and redox biology, and a fine-tuned balance between anti-/proapoptotic proteins. In cancer cells, mitochondria also experience dynamic alterations from the structural point of view undergoing coordinated cycles of biogenesis, fusion/fission and mitophagy, and physically communicating with the endoplasmic reticulum (ER), through the Ca²⁺ flux, at the MAM (mitochondria-associated membranes) levels. This review addresses the peculiar mitochondrial metabolic and structural dynamics occurring in cancer cells and their role in coordinating the balance between cell survival and death. The role of mitochondrial dynamics as effective biomarkers of tumor progression and promising targets for anticancer strategies is also discussed.

Angiogenesis Pathway in Kidney Renal Clear Cell Carcinoma and Its Prognostic Value for Cancer Risk Prediction

Angiogenesis, a process highly regulated by pro-angiogenic and anti-angiogenic factors, is disrupted and dysregulated in cancer. Despite the increased clinical use of angiogenesis inhibitors in cancer therapy, most molecularly targeted drugs have been less effective than expected. Therefore, an in-depth exploration of the angiogenesis pathway is warranted. In this study, the expression of angiogenesis-related genes in various cancers was explored using The Cancer Genome Atlas datasets, whereupon it was found that most of them were protective genes in the patients with kidney renal clear cell carcinoma (KIRC). We divided the samples from the KIRC dataset into three clusters according to the mRNA expression levels of these genes, with the enrichment scores being in the order of Cluster 2 (upregulated expression) > Cluster 3 (normal expression) > Cluster 1 (downregulated expression). The survival curves plotted for the three clusters revealed that the patients in Cluster 2 had the highest overall survival rates. Via a sensitivity analysis of the drugs listed on the Genomics of Drug Sensitivity in Cancer database, we generated IC50 estimates for 12 commonly used molecularly targeted drugs for KIRC in the three clusters, which can provide a more personalized treatment plan for the patients according to angiogenesis-related gene expression. Subsequently, we investigated the correlation between the angiogenesis pathway and classical cancer-related genes as well as that between the angiogenesis score and immune cell infiltration. Finally, we used the least absolute shrinkage and selection operator (LASSO)-Cox regression analysis to construct a risk score model for predicting the survival of patients with KIRC. According to the areas under the receiver operating characteristic (ROC) curves, this new survival model based on the angiogenesis-related genes had high prognostic prediction value. Our results should provide new avenues for the clinical diagnosis and treatment of patients with KIRC.

Metformin-loaded lecithin nanoparticles induce colorectal cancer cytotoxicity via epigenetic modulation of noncoding RNAs

BACKGROUND

Colorectal cancer (CRC) is major aliment around the word, with a cumulative rate of mortality. Metformin (MT) was recently approved as anticancer drug against solid tumors, such as CRC. Resistance to MT therapy remains to be a challenging matter facing the development of possible anti-cancer strategy. To circumvent this problem, MT nano-encapsulation has been introduced to sensitize resistant cancer cells. The purpose of the current study is to explore the MT's aptitude encapsulated in lecithin (LC) and chitosan (CS) nanoparticles to inhibit CRC proliferation through modulations of long noncoding RNAs (lncRNAs), micro RNAs (miRNAs), and some biochemical markers.

METHODS AND RESULTS

Cytotoxic screenings of the newly synthesized MT-based regimens; MT, MT-LC NPs (NP1), MT-CS NPs (NP2), and MT-LC-CS NPs (NP3) against colorectal cancerous Caco-2 and HCT116 cell lines versus normal WI-38 cells were performed. The epigenetic mechanistic effects of these proposed regimens on lncRNAs and miRNAs were investigated. Additionally, some protein levels were assessed in CRC cells upon treatments; YKL-40, PPARγ, E-cadherin (ECN), and VEGF. We resulted that NP1 recorded the highest significant cytotoxic effect on CRC cells. HCT116 cells were more sensitive to the NP1 compared to Caco-2 cells. Intriguingly, it was suggested that NP1 tackled the CRC cells through down-regulation of the H19, HOTTIP, HULC, LINC00641, miR-200, miR-92a, miR-21, YKL-40, PPARγ, and VEGF expressions, as well as up-regulation of the miR-944 and ECN expressions.

CONCLUSIONS

We concluded that the NP1 can potentially be cytotoxic to CRC cells in-vitro by modulating noncoding RNA.

Pitavastatin and metformin synergistically activate apoptosis and autophagy in pancreatic cancer cells

Pancreatic cancer is the seventh leading cause of cancer-related deaths globally. Metformin is the standard first-line of treatment for hyperglycemia in Type 2 diabetes, whereas pitavastatin is a cholesterol-lowering drug used to prevent cardiovascular diseases. Both these agents evidently exert anticancer effects on pancreatic cancer; however, it remains unclear whether cotreatment using them has additive or synergistic anticancer effects on pancreatic cancer. Thus, we herein used the ASPC-1 and PANC-1 cells and treated them with metformin and/or pitavastatin. We performed the cell viability assay, transwell migration assay, and cell cycle analysis using flow cytometry. Western blotting was used to determine protein levels. We found that cotreatment with metformin (30 mM) and pitavastatin (10 μM) significantly reduced cell viability; caused G0/G1 cell cycle arrest; upregulated the expression levels of Bax, PCNA, cleaved PARP-1, cleaved caspase-3, LC3 II, and p27 ^Kip1 /p21^Cip1 ; and inhibited cell migration. The combination index value for cell viability indicated a synergistic interaction between metformin and pitavastatin. Moreover, cotreating the cells with metformin (30 mM) and pitavastatin (10 μM) could preserve mitochondrial function, activate AMPK, and inhibit PI3K/mTOR than treatment with metformin or pitavastatin alone. These findings clearly indicated that metformin plus pitavastatin had a synergistic anticancer effect on pancreatic cancer cells, potentially caused due to the activation of AMPK and inhibition of PI3K/mTOR signaling. Altogether, our results provide that use of metformin plus pitavastatin maybe serve as a chemotherapeutic agent for human pancreatic cancer in future.

Associations of aspirin, statins and metformin with lung cancer risk and related mortality

Given the poor survival of lung cancer patients and the promising observations herein, future studies (RCTs) should further investigate both time- and dose-dependent effects of combination therapies across all categories of prevention of lung cancer. https://bit.ly/3hlYTtY.

Drug Repurposing in Oncology, an Attractive Opportunity for Novel Combinatorial Regimens

The costs of developing, validating and buying new drugs are dramatically increasing. On the other hand, sobering economies have difficulties in sustaining their healthcare systems, particularly in countries with an elderly population requiring increasing welfare. This conundrum requires immediate action, and a possible option is to study the large, already present arsenal of drugs approved and to use them for innovative therapies. This possibility is particularly interesting in oncology, where the complexity of the cancer genome dictates in most patients a multistep therapeutic approach. In this review, we discuss a) Computational approaches; b) preclinical models; c) currently ongoing or already published clinical trials in the drug repurposing field in oncology; and d) drug repurposing to overcome resistance to previous therapies.

Hyperinsulinemia in Obesity, Inflammation, and Cancer

The relative insufficiency of insulin secretion and/or insulin action causes diabetes. However, obesity and type 2 diabetes mellitus can be associated with an absolute increase in circulating insulin, a state known as hyperinsulinemia. Studies are beginning to elucidate the cause-effect relationships between hyperinsulinemia and numerous consequences of metabolic dysfunctions. Here, we review recent evidence demonstrating that hyperinsulinemia may play a role in inflammation, aging and development of cancers. In this review, we will focus on the consequences and mechanisms of excess insulin production and action, placing recent findings that have challenged dogma in the context of the existing body of literature. Where relevant, we elaborate on the role of specific signal transduction components in the actions of insulin and consequences of chronic hyperinsulinemia. By discussing the involvement of hyperinsulinemia in various metabolic and other chronic diseases, we may identify more effective therapeutics or lifestyle interventions for preventing or treating obesity, diabetes and cancer. We also seek to identify pertinent questions that are ripe for future investigation.

How far along are we in revealing the connection between metformin and colorectal cancer?

Colorectal cancer (CRC) is among the most prevalent cancers worldwide, and its prevention and reduction of incidence is imperative. The presence of diabetes has been associated with a 30% increased risk of CRC, likely through the mechanism of hyperinsulinemia, which promotes tumorigenesis via the insulin receptor in the epithelium or by insulin-like growth factor pathways, inflammation, or adipokines, inducing cancer cell proliferation and cancer spread. Metformin, the first-line agent in treating type 2 diabetes, has a chemopreventive role in CRC development. Additionally, preclinical studies suggest synergistic effects of metformin with oxaliplatin in inhibiting in vitro models of colon cancer. Although preclinical studies on the post diagnostic use of metformin were promising and suggested its synergistic effects with chemotherapy, the data on the possible effects of metformin after surgery and other CRC treatment in the clinical setting are less conclusive, and randomized controlled trials are still lacking.

Mechanism and application of metformin in kidney diseases: An update

Metformin is an oral antihyperglycemic drug widely used to treat type 2 diabetes mellitus (T2DM), acting via indirect activation of 5' Adenosine monophosphate-activated Protein Kinase (AMPK). Beyond the anti-diabetic effect, accumulative pieces of evidence have revealed that metformin also everts a beneficial effect in diverse kidney diseases. In various acute kidney diseases (AKI) animal models, metformin protects renal tubular cells from inflammation, apoptosis, reactive oxygen stress (ROS), endoplasmic reticulum (ER) stress, epithelial-mesenchymal transition (EMT) via AMPK activation. In diabetic kidney disease (DKD), metformin also alleviates podocyte loss, mesangial cells apoptosis, and tubular cells senescence through AMPK-mediated signaling pathways. Besides, metformin inhibits cystic fibrosis transmembrane conductance regulator (CFTR)-mediated fluids secretion and the mammalian target of rapamycin (mTOR)-involved cyst formation negatively regulated by AMPK in autosomal dominant polycystic kidney disease (APDKD). Furthermore, metformin also contributes to the alleviation of urolithiasis and renal cell carcinoma (RCC). As the common pathway for chronic kidney disease (CKD) progressing towards end-stage renal disease (ESRD), renal fibrosis is ameliorated by metformin, to a great extent dependent on AMPK activation. However, clinical data are not always consistent with preclinical data, some clinical investigations showed the unmeaningful even detrimental effect of metformin on T2DM patients with kidney diseases. Most importantly, metformin-associated lactic acidosis (MALA) is a vital issue restricting the application of metformin. Thus, we conclude the application of metformin in kidney diseases and uncover the underlying molecular mechanisms in this review.

Metformin and ovarian cancer: the evidence

In recent decades, great interest in the off-label use of metformin has arisen as a result of its broad effects on different signaling pathways, with only a few side effects, and low cost. Metformin has been shown to have multiple, dose-dependent preclinical anticancer effects, which can be roughly divided into either direct effects via inhibition of mitochondrial respiratory chain complex I, or indirect effects through lowered glucose, insulin and insulin-like growth factor levels. Further details on in vitro and in vivo anticancer effects specifically in ovarian cancer are continuously reported. Preclinically metformin has clear chemosensitizing effects in ovarian cancer and it is an effective negative regulator of angiogenesis. There are also some epidemiological studies on metformin use in ovarian cancer, but the results of these studies are not as promising as those preclinical studies would indicate. Most preclinical studies have involved metformin concentrations that are many times higher than the pharmacological doses used in patients, which might confound the clinical use of metformin as regards the above-mentioned aspects. In this review we evaluate preclinical and clinical evidence concerning metformin in ovarian cancer treatment.

Effects of metformin and pioglitazone combination on apoptosis and AMPK/mTOR signaling pathway in human anaplastic thyroid cancer cells

Anaplastic cancer constitutes 1% of thyroid cancers, and it is one of the most aggressive cancers. Treatment options are external radiation therapy and/or chemotherapy. The success rate with these treatment modalities is not satisfactory. We aimed to evaluate the effects of metformin (MET) and pioglitazone (PIO) combination on apoptosis and AMP-activated protein kinase/mammalian target of rapamycin (mTOR) signaling pathway in human anaplastic thyroid cancer cells. In this study, we evaluated the effects of MET and PIO individually and the combination of the two drugs on the cellular lines SW1736 and C643 ATC. Genes contained in the mTOR signaling pathway were examined using human mTOR Signalization RT2 Profiler PCR Array. In C643 and SW1736 cell lines, IC50 doses of MET and PIO were found out as 17.69 mM, 11.64 mM, 27.12 µM, and 23.17 µM. Also, the combination of MET and PIO was determined as an additive according to isobologram analyses. We have found the downregulation of the expression levels of oncogenic genes: AKT3, CHUK, CDC42, EIF4E, HIF1A, IKBKB, ILK, MTOR, PIK3CA, PIK3CG, PLD1, PRKCA, and RICTOR genes, in the MET and PIO combination-treated cells. In addition, expression levels of tumor suppressor genes, DDIT4, DDIT4L, EIF4EBP1, EIF4EBP2, FKBP1A, FKBP8, GSK3B, MYO1C, PTEN, ULK1, and ULK2, were found to have increased significantly. The MET + PIO combination was first applied to thyroid cancer cells, and significant reductions in the level of oncogenic genes were detected. The decreases, particularly, in AKT3, DEPTOR, EIF4E, ILK, MTOR, PIK3C, and PRKCA expressions indicate that progression can be prevented in thyroid cancer cells and these genes could be selected as therapeutic targets.

Diabetes mellitus and survival of esophageal cancer patients after esophagectomy: a systematic review and meta-analysis

Diabetes mellitus (DM) is one of the most common comorbidities in esophageal cancer patients who undergo esophagectomy. It is well established that DM has an unfavorable impact on short-term outcomes of patients with surgically treated esophageal cancer; however, whether DM has any impact on long-term survival of these patients remains unclear. We performed the first meta-analysis to investigate the impact of DM on survival of surgically treated esophageal cancer patients. We searched the following databases systematically to retrieve relevant studies on January 2, 2019: PubMed, Embase, and Web of Science. The main outcome data consisting of 3- and 5-year overall survival (OS) rates and hazard ratios (HRs) of OS were extracted to compare survival between patients with and without DM. We finally included for meta-analysis a total of eight cohort studies involving 5,044 esophageal cancer patients who underwent esophagectomy. We found no significant difference between 3-year (risk ratio [RR] = 0.94, 95% CI: 0.73-1.21; P = 0.65) and 5-year (RR = 0.92, 95% CI: 0.80-1.08; P = 0.31) OS rates between patients with and without DM after esophagectomy. Moreover, DM was not found to be an independent predictor of OS for these patients (HR = 1.10, 95% CI: 0.65-1.84; P = 0.72). Our study suggests that DM appears to have no significant impact on long-term survival of esophageal cancer patients who undergo esophagectomy. To improve the prognosis of these patients, it may be more important to control glycemic level in patients with DM who undergo esophagectomy. However, further high-quality studies with appropriate adjustment for confounding factors are needed to verify this conclusion.

Role of the Wnt signalling pathway in the development of endothelial disorders in response to hyperglycaemia

INTRODUCTION

Diabetes mellitus (DM) is the most common metabolic disease. A WHO report from 2016 indicates that 422 million people worldwide suffer from DM or hyperglycaemia because of impaired glucose metabolism. Chronic hyperglycaemia leads to micro- and macrovessel damage, which may result in life-threatening complications. The Wnt pathway regulates cell proliferation and survival by modulating the expression of genes that control cell differentiation. Three linked Wnt pathways have been discovered thus far: a β-catenin-dependent pathway and two pathways independent of β-catenin - the planar cell polarity pathway and calcium-dependent pathway. The Wnt pathway regulates genes associated with inflammation, cell cycle, angiogenesis, fibrinolysis and other molecular processes.

AREAS COVERED

This review presents the current state of knowledge regarding the contribution of the Wnt pathway to endothelial ageing under hyperglycaemic conditions and provides new insights into the molecular basis of diabetic endothelial dysfunction.

CONCLUSION

The β-catenin-dependent pathway is a potential target in the prophylaxis and treatment of early-stage diabetes-related vascular complications. However, the underlying molecular mechanisms remain largely undetermined and require further investigation.

The effects of Berberis vulgaris consumption on plasma levels of IGF-1, IGFBPs, PPAR-γ and the expression of angiogenic genes in women with benign breast disease: a randomized controlled clinical trial

BACKGROUND

The present study was designed to investigate the effects of Berberis vulgaris (BV) juice consumption on plasma levels of insulin-like growth factor (IGF-1), IGF-binding proteins (IGFBPs), and the expression of PPAR-γ, VEGF and HIF in women with benign breast disease.

METHODS

This parallel design randomized, double-blind controlled clinical trial was conducted on 85 eligible patients diagnosed with benign breast disease. They were assigned randomly into either BV juice group (n = 44, BV juice: 480 ml/day) or placebo group (n = 41, BV placebo juice: 480 ml/day) for 8 weeks intervention. Participants, caregivers and those who assessed laboratory analyses were blinded to the assignments. Plasma levels of biomarkers were measured at baseline and after 8 weeks by ELISA. Quantitative real-time PCR was used to measure the fold change in the expression of each interested gene.

RESULTS

The compliance of participants was 95.2% and 40 available subjects analyzed in each group at last. Relative treatment (RT) effects for BV juice caused 16% fall in IGF-1 concentration and 37% reduction in the ratio of IGF-1/1GFBP1. Absolute treatment effect expressed 111 ng/ml increased mean differences of IGFBP-3 between BV group and placebo. Plasma level of PPAR-γ increased in both groups but it was not significant. Fold changes in the expressions of PPAR-γ, VEGF and HIF showed down-regulation in the intervention group compared to placebos (P < 0.05).

CONCLUSIONS

The BV juice intervention over 8 weeks was accompanied by acceptable efficacy and decreased plasma IGF-1, and IGF-1/IGFBP-1 ratio partly could be assigned to enhanced IGFBP-1 level in women with BBD. The intervention caused reductions in the expression levels of PPAR, VEGF, and HIF which are remarkable genomic changes to potentially prevent breast tumorigenesis.

TRIAL REGISTRATION

IRCT2012110511335N2. Registered 10 July 2013 (retrospectively registered).

Metformin suppresses the proliferation and invasion through NF-kB and MMPs in MCF-7 cell line

Objective

MCF-7 cells, a breast cancer cell line, are used for experiments of estrogen receptor (ER)-positive breast cancer and many sub-clones representing different classes of ER-positive tumors. We aimed to determine the efficacy of metformin, a potential anti-cancer agent, on the cell proliferation, and the expressions of NF-kB (p65), MMP-2 and MMP-9 in MCF-7 cell line.

Materials and methods

MCF-7 cells (human breast adenocarcinoma) were treated with elevating doses of metformin (0–50 mM) for 24 h. The anti-proliferative effect of metformin was studied by BrdU proliferation assay, and the expression levels of NF-kB (p65), MMP-2 and MMP-9 were analyzed by immunocytochemical staining.

Results

The percentage of cell proliferation was reduced significantly by 10 and 50 mM doses of metformin (p < 0.001). The expression levels of nuclear NF-kB (p65), MMP-9 and MMP-2 were considerably reduced in 50 mM metformin treated cells while the expression of cytoplasmic NF-kB (p65) elevated compared to control group (p < 0.05). Ten millimolar metformin also reduced expression of MMP-9 significantly (p < 0.05).

Conclusion

Metformin may act on the proliferation, and the processes of invasion and metastasis of MCF-7 cells through blocking NF-kB, which is intensely expressed in breast cancer cells, and through diminishing the expression of MMP-2 and MMP-9 significantly.

Hepatocellular carcinoma in alcoholic and non-alcoholic fatty liver disease-one of a kind or two different enemies?

Hepatocellular cancer (HCC) is a cancer with an overall poor prognosis and an alarming globally rising incidence. While viral etiology of chronic liver disease and HCC is down-trending, alcohol and excess calorie intake have emerged as major culprits. Alcohol related liver disease (ALD) and non-alcoholic fatty liver disease (NAFLD) share similar pathogenetic mechanism of hepatic injury and in promoting development of HCC; yet some genetic and epigenetic features are distinct and may promise clinical utility. Population based intervention are urgently needed to reduce alcohol use and improve metabolic factors such as obesity and diabetes. The goal is to identify at-risk patients, to link these patients to care and to provide effective management of chronic liver disease and HCC. This review focuses on the epidemiology, pathophysiology including genetic and epigenetic altercation as well as clinical aspects of ALD and NAFLD associated HCC.

Metformin as an adjuvant in breast cancer treatment

Breast cancer is one of the most common malignancies in females. It is an etiologically complex disease driven by a multitude of cellular pathways. The proliferation and spread of breast cancer is intimately linked to cellular glucose metabolism, given that glucose is an essential cellular metabolic substrate and that insulin signalling has mitogenic effects. Growing interest has focused on anti-diabetic agents in the management of breast cancer. Epidemiologic studies show that metformin reduces cancer incidence and mortality among type 2 diabetic patients. Preclinical in vitro and in vivo research provides intriguing insight into the cellular mechanisms behind the oncostatic effects of metformin. This article aims to provide an overview of the mechanisms in which metformin may elicit its anti-cancerous effects and discuss its potential role as an adjuvant in the management of breast cancer.

A Cohort Study of Metformin and Colorectal Cancer Risk among Patients with Diabetes Mellitus

Background: Several epidemiologic studies have reported strong inverse associations between metformin use and risk of colorectal cancer, although time-related biases, such as immortal time bias, may in part explain these findings. We reexamined this association using methods to minimize these biases.Methods: A cohort study was conducted among 47,351 members of Kaiser Permanente Northern California with diabetes and no history of cancer or metformin use. Follow-up for incident colorectal cancer occurred from January 1, 1997, until June 30, 2012. Cox regression was used to calculate HRs and 95% confidence intervals (CIs) for colorectal cancer risk associated with metformin use (ever use, total duration, recency of use, and cumulative dose).Results: No association was observed between ever use of metformin and colorectal cancer risk (HR, 0.90; 95% CI, 0.76-1.07) and there was no consistent pattern of decreasing risk with increasing total duration, dose, or recency of use. However, long-term use (≥5.0 years) appeared to be associated with reduced risk of colorectal cancer in the full population (HR, 0.78; 95% CI, 0.60-1.02), among current users (HR, 0.78; 95% CI, 0.59-1.04), and in men (HR, 0.65; 95% CI, 0.45-0.94) but not in women. Higher cumulative doses of metformin were associated with reduced risk. In initial users of sulfonylureas, switching to or adding metformin was also associated with decreased colorectal cancer risk.Conclusions: Our findings showed an inverse association between long-term use of metformin and colorectal cancer risk. Findings, especially the risk reduction among men, need to be confirmed in large, well-conducted studies.Impact: If our findings are confirmed, metformin may have a role in the chemoprevention of colorectal cancer. Cancer Epidemiol Biomarkers Prev; 27(5); 525-30. ©2018 AACRSee related commentary by Jackson and García-Albéniz, p. 520.

A pooled analysis of two phase II trials evaluating metformin plus platinum-based chemotherapy in advanced non-small cell lung cancer

BACKGROUND

Despite a wealth of preclinical and observational data, prospective data regarding the use of metformin in lung cancer is extremely limited.

METHODS

We pooled individualized data from two prospective trials evaluating metformin plus platinum-based chemotherapy, with or without bevacizumab, in non-diabetic patients with untreated advanced NSCLC. In addition to reporting on clinical efficacy and safety endpoints, we also explored metformin's activity in key molecular cohorts.

RESULTS

33 patients were included in the pooled analysis, of whom 70% were current or previous smokers. 82% had standard tissue molecular testing results available. KRAS, EGFR, and LKB1 mutation prevalence was 48%, 26%, and 8.3%, respectively. Composite median PFS was 6 months for all patients (95% CI: [1.36, 7.96]), 7.2 months for KRAS mutants (95% CI: [1.18, 9.21]), and 6.6 months for EGFR mutants (95% CI: [1.18, 15.29]). Composite median OS was 14.8 months for all patients (95% CI: [8.25, 19.99]), 17.5 months for KRAS mutants (95% CI: [8.86, 26.96]), and 13.3 months for EGFR mutants (95% CI: [2.60, 25.86]). Lymphopenia was the most common grade 3 AE (12%), followed by leukopenia, nausea, vomiting, and hypertension (9% each). There were 2 grade 4 AEs, neutropenia (21%) and sepsis (3%), and 1 grade 5 AE (colonic perforation) attributed to bevacizumab.

CONCLUSION

Our results confirm the previously shown efficacy and tolerability of metformin in combination with chemotherapy and highlight encouraging activity in key molecular cohorts. Future efforts should build on this work by prospectively studying metformin in these molecular subgroups.

Metformin Induces Different Responses in Clear Cell Renal Cell Carcinoma Caki Cell Lines

Clear cell renal cell carcinoma (ccRCC) is the most common and lethal form of urological cancer diagnosed globally. Mutations of the von Hippel-Lindau (VHL) tumor-suppressor gene and the resultant overexpression of hypoxia-inducible factor (HIF)-1α protein are considered hallmarks of ccRCC. Persistently activated HIF-1α is associated with increased cell proliferation, angiogenesis, and epithelial–mesenchymal transition (EMT), consequently leading to ccRCC progression and metastasis to other organs. However, the VHL status alone cannot predict the differential sensitivity of ccRCC to cancer treatments, which suggests that other molecular differences may contribute to the differential response of ccRCC cells to drug therapies. In this study, we investigated the response to metformin (an antidiabetic drug) of two human ccRCC cell lines Caki-1 and Caki-2, which express wild-type VHL. Our findings demonstrate a differential response between the two ccRCC cell lines studied, with Caki-2 cells being more sensitive to metformin compared to Caki-1 cells, which could be linked to the differential expression of HIF-1α despite both cell lines carrying a wild-type VHL. Our study unveils the therapeutic potential of metformin to inhibit the progression of ccRCC in vitro. Additional preclinical and clinical studies are required to ascertain the therapeutic efficacy of metformin against ccRCC.

NF-κB as the mediator of metformin's effect on ageing and ageing-related diseases

Ageing can be defined as the progressive failure of repair and maintenance systems with a consequent accumulation of cellular damage in nucleic acids, proteins, and lipids. These various types of damage promote ageing by driving cellular senescence and apoptosis. The nuclear factor-kappa B (NF-kB) pathway is one of the key mediators of ageing and this pathway is activated by genotoxic, oxidative and inflammatory stress, and regulates expression of cytokines, growth factors, and genes that regulate apoptosis, cell-cycle progression, and inflammation. Therefore, NF-kB is increased in a variety of tissues with ageing, thus the inhibition of NF-kB leads to delayed onset of ageing-related symptoms and pathologies such as diabetes, atherosclerosis, and cancer. Metformin is often used as an anti-diabetic medication in type 2 diabetes throughout the world and appears to be a potential anti-ageing agent. Owing to its antioxidant, anticancer, cardio-protective and anti-inflammatory properties, metformin has become a potential candidate drug, improving in the context of ageing and ageing-related diseases. An inappropriate NF-kB activation is associated with diseases and pathologic conditions which can impair the activity of genes involved in cell senescence, apoptosis, immunity, and inflammation. Metformin, inhibiting the expression of NF-kB gene, eliminates the susceptibility to common diseases. This review underlines the pleiotropic effects of metformin in ageing and different ageing-related diseases and attributes its effects to the modulation of NF-kB.

Linking type 2 diabetes and gynecological cancer: an introductory overview

Type 2 diabetes (T2D) is a chronic disease with a growing prevalence and a leading cause of death in many countries. Several epidemiological studies observed an association between T2D and increased risk of many types of cancer, such as gynecologic neoplasms (endometrial, cervical, ovarian and vulvar cancer). Insulin resistance, chronic inflammation and high free ovarian steroid hormones are considered the possible mechanisms behind this complex relationship. A higher risk of endometrial cancer was observed in T2D, even though this association largely attenuated after adjusting for obesity. A clear relationship between the incidence of cervical cancer (CC) and T2D has still not be determined; however T2D might have an impact on prognosis in patients with CC. To date, studies on the association between T2D and ovarian cancer (OC) are limited. The effect of pre-existing diabetes on cancer-specific mortality has been evaluated in several studies, with less clear results. Other epidemiological and experimental studies focused on the potential role of diabetes medications, mainly metformin, in cancer development in women. The correct understanding of the link between T2D and gynecologic cancer risk and mortality is currently imperative to possibly modify screening and diagnostic-therapeutic protocols in the future.

A pharmacodynamic study of sirolimus and metformin in patients with advanced solid tumors

BACKGROUND

Sirolimus is a mammalian target of rapamycin (mTOR) inhibitor. Metformin may potentiate mTOR inhibition by sirolimus while mitigating its adverse effects. We conducted a pilot study to test this hypothesis.

METHODS

Patients with advanced solid tumor were treated with sirolimus for 7 days followed by randomization to either sirolimus with metformin (Arm A) or sirolimus (Arm B) until day 21. From day 22 onwards, all patients received sirolimus and metformin. The primary aim was to compare the change in phospho-p70S6K (pp70S6K) in peripheral blood mononuclear cells (PBMC) from day 8 to day 22 using a two-sample t test. Secondary aims were objective response rate, toxicity, and other serum pharmacodynamic biomarkers (e.g., fasting glucose, triglycerides, insulin, C-peptide, IGF-1, IGF-1R, IGF-BP, and leptin).

RESULTS

24 patients were enrolled, with 18 evaluable for the primary endpoint. There was no significant difference in mean change in pp70S6K in arm A vs. arm B (- 0.12 vs. - 0.16; P = 0.64). Similarly, there were no significant differences in other serum pharmacodynamic biomarkers. There were no partial responses. There were no dose-limiting or unexpected toxicities.

CONCLUSIONS

Adding metformin to sirolimus, although well tolerated, was not associated with significant changes in pp70S6K in PBMC or other serum pharmacodynamic biomarkers.

IMPACT

Combining metformin with sirolimus did not improve mTOR inhibition.

Combination of metformin and 9-cis retinoic acid increases apoptosis in C6 glioma stem-like cells

Glioblastoma (GBM) is the most commonly diagnosed type of brain cancer and the leading cause of brain cancer-related death. GBM contains a subpopulation of tumor-propagating glioblastoma stem-like cells that are thought to drive cancer progression and recurrence. Although several clinical trials are ongoing to explore new chemotherapeutic agents to treat GBM, the use of metformin (Met), a first-line drug for type 2 diabetes mellitus, in cancer remains controversial. Here, we show that combining Met with 9-cis retinoic acid (9-cis RA) reduced the proliferation rate of C6-GSCs (glioblastoma stem-like cells) in vitro. The results of flow cytometric analysis showed that treatment with 9-cis RA for 24 h induced 4.5% early and 38.0% late apoptosis in C6-GSCs. Twenty-four hours of Met treatment induced 23.6% early and 33.5% late apoptosis in C6-GSCs. Combination of Met and 9-cis RA treatment significantly increased both early and late apoptosis to 30.4% and 55.4%, respectively. The present findings suggest that not only 9-cis RA but also Met has the potential to induce early and late apoptotic GSCs death by affecting the functional cytoplasmic and nuclear organelles. At the protein level, there was increased cleaved caspase-3 but decreased procaspase-3 expression in Met-, 9-cis RA- and Met+9-cis RA-treated C6 GSCs, as detected by western blotting. The ratio of cleaved caspase-3/procaspase-3 was 1.6 times higher in Met+9-cis RA-treated groups compared to control. Ultimately, a combination of Met and 9-cis RA might be a possible therapeutic target for the treatment of GBM.

Should we undertake surveillance for HCC in patients with NAFLD?

The pandemic of obesity and its related complications is rapidly changing the epidemiology of many types of cancer, including hepatocellular carcinoma (HCC). Non-alcoholic fatty liver disease (NAFLD) is becoming a major cause of HCC, with a steadily rising trend compared to viral or alcohol-induced chronic hepatitis. The much greater prevalence of the underlying liver disease in the general population and the chance of HCC occurrence in non-cirrhotic liver are the most worrisome aspects of HCC in NAFLD. Effective screening programmes are currently hampered by limited knowledge of the pathways of carcinogenesis and a lack of tools able to stratify the risk of HCC in the NAFLD population. Hence, poor surveillance has prevented the development of an adequate treatment for NAFLD-related HCC. Systemic and hepatic molecular mechanisms involved in hepatocarcinogenesis, as well as potential early markers of HCC are being extensively investigated. This review describes the current clinical impact of HCC in NAFLD and discusses the most important unmet needs for its effective management.

Metformin: Focus on Melanoma

Metformin is the most common biguanide used in the treatment of diabetes, with 120 million treated patients worldwide. Metformin decreases hyperglycemia without inducing hypoglycemia in diabetic patients and is very well tolerated. The principal effects of metformin are to decrease hepatic gluconeogenesis and increase glucose absorption by skeletal muscles. These effects are primarily due to metformin's action on mitochondria, which requires the activation of metabolic checkpoint AMP-activated protein kinase (AMPK). AMPK is implicated in several pathways, and following metformin activation, it decreases protein synthesis and cell proliferation. Many studies have examined the role of metformin in the regulation of cancer cells, particularly its effects on cancer cell proliferation and cell death. Encouraging results have been obtained in different types of cancers, including prostate, breast, lung, and skin cancers (melanoma). Furthermore, many retrospective epidemiological studies in diabetes patients have shown that metformin treatment decreased the risk of cancers compared with other antidiabetic treatments. In this review, we will discuss the effects of metformin on melanoma cells. Together, our novel data demonstrate the importance of developing metformin and new biguanide-derived compounds as potential treatments against a number of different cancers, particularly melanoma.

Ginkgolic acid inhibits the invasiveness of colon cancer cells through AMPK activation

Tumor cell invasion and metastasis are important processes in colorectal cancer that exert negative effects on patient outcomes; consequently, a prominent topic in the field of colorectal cancer study is the identification of safe and affordable anticancer drugs against cell invasion and metastasis, with limited side effects. Ginkgolic acid is a phenolic acid extracted from ginkgo fruit, ginkgo exotesta and ginkgo leaves. Previous studies have indicated that ginkgolic acid inhibits tumor growth and invasion in a number of types of cancer; however, limited studies have considered the effects of ginkgolic acid on colon cancer. In the present study, SW480 colon cancer cells were treated with a range of concentrations of ginkgolic acid; tetrazolium dye-based MTT, wound-scratch and transwell migration assays were performed to investigate the effects on the proliferation, migration and invasion of colon cancer cells, and potential mechanisms for the effects were explored. The results indicated that ginkgolic acid reduced the proliferation and significantly inhibited the migration and invasion of SW480 cells in a concentration-dependent manner. Additional experiments indicated that ginkgolic acid significantly decreased the expression of invasion-associated proteins, including matrix metalloproteinase (MMP)-2, MMP-9, urinary-type plasminogen activator and C-X-C chemokine receptor type 4, and activated adenosine monophosphate activated protein kinase (AMPK) in SW480 cells. Small interfering RNA silencing of AMPK expression reversed the effect of ginkgolic acid on the expression of invasion-associated proteins. This result suggested that ginkgolic acid inhibited the proliferation, migration and invasion of SW480 colon cancer cells by inducing AMPK activation and inhibiting the expression of invasion-associated proteins.

Sirolimus and Metformin Synergistically Inhibits Colon Cancer In Vitro and In Vivo

We estimated the effect of various immunosuppressants (ISs) and metformin (M) to provide theoretical background of optimal therapeutic strategy for de novo colon cancer after liver transplantation (LT). Three colon cancer cell lines (HT29, SW620, and HCT116) were used in in vitro studies. HT29 was also used in BALB/c-nude mice animal models. Following groups were used in both in vitro and in vivo studies: sirolimus (S), tacrolimus (T), cyclosporin A (CsA), M, metformin/sirolimus (Met/S), metformin/tacrolimus (Met/T), and metformin/cyclosporin A (Met/CsA). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed and western blot analyses were performed for mTOR pathway proteins, apoptosis proteins, and epithelial-mesenchymal-transition (EMT) proteins. Tumor volume was measured for 4 weeks after inoculation. MTT-assay revealed significant cell viability inhibition in all 3 colon cancer cell lines in groups of S, M, and Met/S. Of note, group Met/S showed synergistic effect compare to M or S group. Western blot analysis showed significant low levels of all investigated proteins in groups of S and Met/S in both in vitro and in vivo experiment. Tumor growth was significantly inhibited only in the Met/S group. Combination of Met and S showed the most potent inhibition in all colon cancer cell lines. This finding might have application for de novo colon cancer.

Berberine Enhances Chemosensitivity and Induces Apoptosis Through Dose-orchestrated AMPK Signaling in Breast Cancer

Breast cancer is the most common malignancy in women. Although personalized or targeting molecular cancer therapy is more popular up to now, the cytotoxicity chemotherapy for patients with advanced breast cancer is considered as the alternative option. However, chemoresistance is still the common and critical limitation for breast cancer treatment. Berberine, known as AMPK activator, has shown multiple activities including antitumor effect. In this study, we investigate the chemosensitive effect of different dosages berberine on drug-resistant human breast cancer MCF-7/MDR cell in vitro and in vivo, and the mechanisms underlying AMPK activation on Doxorubicin (DOX) chemosensitivity. Our results showed that berberine could overcome DOX resistance in dose-orchestrated manner: On one hand, low-dose berberine can enhance DOX sensitivity in drug-resistance breast cancer cells through AMPK-HIF-1α-P-gp pathway. On the other hand, high-dose berberine alone directly induces apoptosis through the AMPK-p53 pathway with the independence of HIF-1α expression. Taken together, our findings demonstrate that berberine sensitizes drug-resistant breast cancer to DOX chemotherapy and directly induces apoptosis through the dose-orchestrated AMPK signaling pathway in vitro and in vivo. Berberine appears to be a promising chemosensitizer and chemotherapeutic drug for breast cancer treatment.

Metformin in Lung Cancer: Review of in Vitro and in Vivo Animal Studies

Cancer cells display enhanced growth rates and a resistance to apoptosis. The ability of cancer cells to evade homeostasis and proliferate uncontrollably while avoiding programmed cell death/apoptosis is acquired through mutations to key signaling molecules, which regulate pathways involved in cell proliferation and survival and these mutations allow them to develop resistance to many chemotherapeutic agents, highlighting the need for development of new potent anti-cancer agents. Metformin has long been used as a treatment for type 2 diabetes and has recently attracted attention as a potential agent to be used in the treatment of cancer. The present review summarizes the existing in vitro and in vivo animal studies focusing on the anti-lung cancer effects of metformin and its effects on key proliferative and anti-apoptotic signaling pathways.

Colon cancer modulation by a diabetic environment: A single institutional experience

Background

Multiple observational studies suggest an increased risk of colon cancer in patients with diabetes mellitus (DM). This can theoretically be the result of an influence of the diabetic environment on carcinogenesis or the tumor biologic behavior.

Aim

To gain insight into the influence of a diabetic environment on colon cancer characteristics and outcomes.

Material and methods

Retrospective analysis of clinical records in an academic tertiary care hospital with detailed analysis of 81 diabetic patients diagnosed of colon cancer matched with 79 non-diabetic colon cancer patients. The impact of streptozotocin-induced diabetes on the growth of colon cancer xenografts was studied in mice.

Results

The incidence of DM in 1,137 patients with colorectal cancer was 16%. The diabetic colon cancer cases and non-diabetic colon cancer controls were well matched for demographic and clinical variables. The ECOG Scale Performance Status was higher (worse) in diabetics (ECOG ≥1, 29.1% of controls vs 46.9% of diabetics, p = 0.02), but no significant differences were observed in tumor grade, adjuvant therapy, tumor site, lymphovascular invasion, stage, recurrence, death or cancer-related death. Moreover, no differences in tumor variables were observed between patients treated or not with metformin. In the xenograft model, tumor growth and histopathological characteristics did not differ between diabetic and nondiabetic animals.

Conclusion

Our findings point towards a mild or negligible effect of the diabetes environment on colon cancer behavior, once cancer has already developed.

Risk factors for cancer development in type 2 diabetes: A retrospective case-control study

BACKGROUND

The risk of several types of cancer is increased in type 2 diabetes mellitus. The earliest possible diagnosis of cancer - difficult within regular outpatient diabetes care - is of utmost importance for patients' survival. The aim of this multicenter, retrospective (years 1998-2015), case-control study was to identify risk factors associated with malignancy in subjects with diabetes treated in a typical outpatient setting.

METHODS

In the databases of 3 diabetic and 1 primary care clinics 203 patients (115 women) with type 2 diabetes mellitus who developed malignancy while treated for diabetes were identified. The control group consisted of 203 strictly age- and gender matched subjects with type 2 diabetes without cancer. Factors associated with diabetes: disease duration, antidiabetic medications use and metabolic control of diabetes were analyzed. Also other variables: BMI (body mass index), smoking habits, place of residence and comorbidities were included into analysis.

RESULTS

The most prevalent malignancies in men and women together were breast cancer (20.7 %) and colorectal cancer (16.3 %). HbA1c (hemoglobin A1c) level ≥8.5 %, obesity and insulin treatment in dose-dependent and time-varying manner demonstrated significant association with increased risk of malignancy, while metformin use was associated with a lower risk of cancer. Diabetes duration, comorbidities, smoking habits, place of residence and aspirin use did not show significant association with risk of malignancy.

CONCLUSIONS

In the outpatient setting the obese patients with poorly controlled insulin treated type 2 diabetes mellitus should be rigorously assessed towards malignancies, particularly breast cancer in women and colorectal cancer in men.

Impact of Glycemic Control and Metformin Use on the Recurrence and Progression of Non-Muscle Invasive Bladder Cancer in Patients with Diabetes Mellitus

The purpose of the present study was to determine the potential relationships of glycemic control and use of metformin with non-muscle invasive bladder cancer characteristics. We reviewed data from 645 patients with non-muscle invasive bladder cancer between January 2004 and May 2015. We analyzed the association of pre and post-operative glycemic control and use of metformin with clinical characteristics of bladder tumors. We also analyzed the association of glycemic control and use of metformin with recurrence-free and progression-free survivals. Diabetes mellitus patients showed decreased recurrence-free survival (hazard ratio 1.42; 95% confidence interval 1.1-1.9; P = 0.021) and progression-free survival (hazard ratio 1.79; 95% confidence interval 1.1-2.8; P = 0.013). Diabetes mellitus patients with a HbA1c ≥ 7.0% demonstrated a higher rate of progression (P = 0.026). Kaplan-Meier analysis showed that progression-free survival rate was associated with poor baseline glycemic control (P = 0.026) and post-operative glycemic control (P = 0.025). However, use of metformin had no impact on the recurrence (P = 1.00) and progression (P = 0.282). In conclusion, poor baseline and post-operative glycemic control was related with shorter progression-free survival of patients with non-muscle invasive bladder cancer. Use of metformin had no impact on the recurrence and progression. Therefore, tight glycemic control and close follow-up for bladder tumor may be beneficial in patients with poor glycemic control.

Metformin Addition to Chemotherapy in Stage IV Non-Small Cell Lung Cancer: an Open Label Randomized Controlled Study

PURPOSE

To evaluate effects of metformin on clinical outcome of non-diabetic patients with stage IV NSCLC.

MATERIALS AND METHODS

A prospective, randomized, open-label, controlled pilot study was conducted on patients with stage IV NSCLC with an Eastern Cooperative Oncology Group Performance Status (ECOG PS) of 0-2, excluding patients with diabetes and lactic acidosis. Thirty chemo-naive, non-diabetic patients with stage IV NSCLC were enrolled. Fifteen patients received intravenous gemcitabine/cisplatin regimen alone (arm B) while fifteen patients received the same regimen plus daily oral metformin 500 mg (arm A). The effect of metformin on chemotherapy-response rates, survival, and adverse events in these patients was evaluated.

RESULTS

Objective response rate (ORR) and median overall survival (OS) in arms A and B were 46.7% versus 13.3% respectively, p=0.109 and 12 months versus 6.5 months, respectively, p=0.119. Median progression free survival (PFS) in arms A and B was 5.5 months versus 5 months, p=0.062. No significant increase in toxicity was observed in arm A versus arm B. Percentage of patients who experienced nausea was significantly lower in arm A versus arm B, at 26.7% versus 66.7% respectively, p=0.028.

CONCLUSIONS

Metformin administration reduced occurrence of chemotherapy induced-nausea. Non-statistically significant improvements in the ORR or OS were observed. Metformin had no effect on PFS.