Diabetes, cancer, and metformin: connections of metabolism and cell proliferation

Keratin: A potential driver of tumor metastasis

Keratins, as essential components of intermediate filaments in epithelial cells, play a crucial role in maintaining cell structure and function. In various malignant epithelial tumors, abnormal keratin expression is frequently observed and serves not only as a diagnostic marker but also closely correlates with tumor progression. Extensive research has demonstrated that keratins are pivotal in multiple stages of tumor metastasis, including responding to mechanical forces, evading the immune system, reprogramming metabolism, promoting angiogenesis, and resisting apoptosis. Here we emphasize that keratins significantly enhance the migratory and invasive capabilities of tumor cells, making them critical drivers of tumor metastasis. These findings highlight the importance of targeting keratins as a strategic approach to combat tumor metastasis, thereby advancing our understanding of their role in cancer progression and offering new therapeutic opportunities.

A risk prediction model for endometrial hyperplasia/endometrial carcinoma in premenopausal women

This study investigated the risk factors for endometrial hyperplasia (EH) and endometrial carcinoma (EC) in premenopausal women. The goal was to establish a nomogram model to predict the risk of EH/EC and quantitative standards in clinical practice, which improved the clinical prognosis of EH/EC patients. Data were collected from premenopausal women with suspected EH/EC who underwent hysteroscopic endometrial biopsy. Patients (n = 1541) were divided into training and validation groups at a 3:1 ratio. Univariable and multivariable logistic regression analyses were conducted to identify risk factors for EH/EC and establish a predictive model. The model's discrimination was evaluated using the area under the receiver operating characteristic curve (AUC), its calibration was assessed using calibration plots, and its clinical effectiveness was evaluated using decision curve analysis (DCA). The optimal score and probability cutoff values were determined to differentiate between low and high-risk populations, guiding clinical medical practice. BMI, age at menarche, intrauterine device (IUD), diabetes, polycystic ovary syndrome (PCOS), endometrial thickness (ET), and uterine cavity fluid were identified as independent risk factors for EH/EC and were incorporated into the predictive nomogram model. The model demonstrated good discrimination with AUCs of 0.845 and 0.905 in the training and validation sets, respectively. The calibration plots and DCA showed excellent model calibration and clinical effectiveness. EH/EC is significantly associated with BMI, age at menarche, IUD use, diabetes, PCOS, ET, and uterine cavity fluid. The nomogram model can be used to predict the risk of EH/EC in premenopausal women and facilitate rapid screening.

Connection between oral health and chronic diseases

Chronic diseases have emerged as a paramount global health burden, accounting for 74% of global mortality and causing substantial economic losses. The oral cavity serves as a critical indicator of overall health and is inextricably linked to chronic disorders. Neglecting oral health can exacerbate localized pathologies and accelerate the progression of chronic conditions, whereas effective management has the potential to reduce their incidence and mortality. Nevertheless, limited resources and lack of awareness often impede timely dental intervention, delaying optimal therapeutic measures. This review provides a comprehensive analysis of the impact of prevalent chronic diseases-such as diabetes mellitus, rheumatoid arthritis, cardiovascular disorders, and chronic respiratory diseases-on oral health, along with an exploration of how changes in oral health affect these chronic conditions through both deterioration and intervention mechanisms. Additionally, novel insights into the underlying pathophysiological mechanisms governing these relationships are presented. By synthesizing these advancements, this review aims to illuminate the complex interrelationship between oral health and chronic diseases while emphasizing the urgent need for greater collaboration between dental practitioners and general healthcare providers to improve overall health outcomes.

Chinese herbal medicine decreases incidence of hepatocellular carcinoma in diabetes mellitus patients with regular insulin management

BACKGROUND

Type 2 diabetes mellitus (DM) is an independent risk factor for hepatocellular carcinoma (HCC), while insulin is a potent mitogen. Identifying a new therapeutic modality for preventing insulin users from developing HCC is a critical goal for researchers.

AIM

To investigate whether regular herbal medicine use can decrease HCC risk in DM patients with regular insulin control.

METHODS

We used data acquired from the Taiwanese National Health Insurance research database between 2000 and 2017. We identified patients with DM who were prescribed insulin for > 3 months. The herb user group was further defined as patients prescribed herbal medication for DM for > 3 months per annum during follow-up. We matched the herb users to nonusers at a 1:3 ratio according to age, sex, comorbidities and index year by propensity score matching. We analyzed HCC incidence, HCC survival rates, and the herbal prescriptions involved.

RESULTS

We initially enrolled 657144 DM patients with regular insulin use from 2000 to 2017. Among these, 46849 patients had used a herbal treatment for DM, and 140547 patients were included as the matched control group. The baseline variables were similar between the herb users and nonusers. DM patients with regular herb use had a 12% decreased risk of HCC compared with the control group [adjusted hazard ratio (aHR) = 0.88, 95%CI = 0.80-0.97]. The cumulative incidence of HCC in the herb users was significantly lower than that of the nonusers. Patients with a herb use of > 5 years cumulatively exhibited a protective effect against development of HCC (aHR = 0.82, P < 0.05). Of patients who developed HCC, herb users exhibited a longer survival time than nonusers (aHR = 0.78, P = 0.0001). Additionally, we report the top 10 herbs and formulas in prescriptions and summarize the potential pharmacological effects of the constituents. Our analysis indicated that Astragalus propinquus (Huang Qi) plus Salvia miltiorrhiza Bunge (Dan Shen), and Astragalus propinquus (Huang Qi) plus Trichosanthes kirilowii Maxim. (Tian Hua Fen) were the most frequent combination of single herbs. Meanwhile, Ji Sheng Shen Qi Wan plus Dan Shen was the most frequent combination of herbs and formulas.

CONCLUSION

This large-scale retrospective cohort study reveals that herbal medicine may decrease HCC risk by 12% in DM patients with regular insulin use.

SNPs-Panel Polymorphism Variations in GHRL and GHSR Genes Are Not Associated with Prostate Cancer

Prostate cancer (PCa) is a major public health problem worldwide. Recent studies have suggested that ghrelin and its receptor could be involved in the susceptibility to several cancers such as PCa, leading to their use as an important predictive way for the clinical progression and prognosis of cancer. However, conflicting results of single nucleotide polymorphisms (SNPs) with ghrelin (GHRL) and its receptor (GHSR) genes were demonstrated in different studies. Thus, the present case-control study was undertaken to investigate the association of GHRL and GHSR polymorphisms with the susceptibility to sporadic PCa. A cohort of 120 PCa patients and 95 healthy subjects were enrolled in this study. Genotyping of six SNPs was performed: three tag SNPs in GHRL (rs696217, rs4684677, rs3491141) and three tag SNPs in the GHSR (rs2922126, rs572169, rs2948694) using TaqMan. The allele and genotype distribution, as well as haplotypes frequencies and linked disequilibrium (LD), were established. Multifactor dimensionality reduction (MDR) analysis was used to study gene-gene interactions between the six SNPs. Our results showed no significant association of the target polymorphisms with PCa (p > 0.05). Nevertheless, SNPs are often just markers that help identify or delimit specific genomic regions that may harbour functional variants rather than the variants causing the disease. Furthermore, we found that one GHSR rs2922126, namely the TT genotype, was significantly more frequent in PCa patients than in controls (p = 0.040). These data suggest that this genotype could be a PCa susceptibility genotype. MDR analyses revealed that the rs2922126 and rs572169 combination was the best model, with 81.08% accuracy (p = 0.0001) for predicting susceptibility to PCa. The results also showed a precision of 98.1% (p < 0.0001) and a PR-AUC of 1.00. Our findings provide new insights into the influence of GHRL and GHSR polymorphisms and significant evidence for gene-gene interactions in PCa susceptibility, and they may guide clinical decision-making to prevent overtreatment and enhance patients' quality of life.

Global trends in hepatocellular carcinoma epidemiology: implications for screening, prevention and therapy

Hepatocellular carcinoma (HCC) mortality rates are increasing globally, and particularly in the Western world. Cirrhosis remains the predominant risk factor for HCC. However, epidemiological shifts in the incidence of HCC from patients with virus-related liver disease to those with non-viral aetiologies, including alcohol-associated and metabolic dysfunction-associated steatotic liver disease, have important implications for prevention, surveillance and treatment. Hepatitis B vaccination and antiviral therapy for hepatitis B and C are effective for primary prevention of virus-related HCCs, but chemoprevention strategies for non-viral liver disease remain an unmet need. Emerging data suggest associations between aspirin, statins, metformin and coffee and reduced HCC incidence, although none has been proved to be causally related. Secondary prevention of HCC via semi-annual surveillance is associated with improvements in early detection and thus reduced mortality; however, current tools, including abdominal ultrasonography, have suboptimal sensitivity for the detection of early stage HCC, particularly in patients with obesity and/or non-viral liver disease. Promising blood-based or imaging-based surveillance strategies are emerging, although these approaches require further validation before adoption in clinical practice. In the interim, efforts should be focused on maximizing use of the existing surveillance tools given their prevalent underuse globally. Remarkable advances have been made in the treatment of HCC, including expanded eligibility for surgical therapies, improved patient selection for locoregional treatments and increased systemic treatment options, including immune-checkpoint inhibitors. In this Review, we discuss trends in the epidemiology of HCC and their implications for screening, prevention and therapy.

Clinical potentials of metformin in cancer therapy

Diabetes is a prevalent metabolic disorder that results in several comorbidities including cancer. Cancer becomes the most severe complication of diabetes patients. Growing evidence proved that impaired glucose homeostasis is an independent risk factor for the occurrence of various types of cancers including liver, pancreatic, gastric (stomach), colorectal, kidney, and breast cancers, and influences cancer prognosis. Diabetes mellitus and cancer have a bidirectional relationship, thus there is a need to look for drugs that can be beneficial in treating both diseases. Therefore, more research is focusing on evaluating the role of antihyperglycemic agents in the treatment of various types of cancers. Metformin, an FDA-approved first-line antihyperglycemic agent can be used as a monotherapy or as an adjuvant to chemotherapeutic agents in the treatment of various types of cancer. However, the exact mechanism of metformin as an anticancer agent is still unknown, the majority of the described putative mechanisms focus on promoting the activity of the AMP-activated protein kinase (AMPK) pathway. This review article thus gives insights into the prognosis of cancer in diabetes patients and aims to explore the possible mechanism of action of metformin in the prevention and treatment of cancer.

Ability of metformin to deplete NAD+ contributes to cancer cell susceptibility to metformin cytotoxicity and is dependent on NAMPT expression

Background

Nicotinamide adenine dinucleotide (NAD+) is vital for not only energy metabolism but also signaling pathways. A major source of NAD+ depletion is the activation of poly (ADP-ribose) polymerase (PARP) in response to DNA damage. We have previously demonstrated that metformin can cause both caspase-dependent cell death and PARP-dependent cell death in the MCF7 breast cancer cells but not in the MDA-MB-231 (231) breast cancer cells while in high-glucose media. We hypothesize that depletion of NAD+ in MCF7 cells via activation of PARP contributes to the cell death caused by metformin. Nicotinamide phosphoribosyltransferase (NAMPT), a key rate-limiting step in converting nicotinamide (vitamin B3) into NAD+, is essential for regenerating NAD+ for normal cellular processes. Evidence shows that overexpression of NAMPT is associated with tumorigenesis. We hypothesize that NAMPT expression may determine the extent to which cancer cells are sensitive to metformin.

Results

In this study, we found that metformin significantly decreases NAD+ levels over time, and that this could be delayed by PARP inhibitors. Pretreatment with NAD+ in MCF7 cells also prevents cell death and the enlargement of mitochondria and protects mitochondria from losing membrane potential caused by metformin. This leads to MCF7 cell resistance to metformin cytotoxicity in a manner similar to 231 cells. By studying the differences in NAD+ regulation in these two breast cancer cell lines, we demonstrate that NAMPT is expressed at higher levels in 231 cells than in MCF7 cells. When NAMPT is genetically repressed in 231 cells, they become much more sensitive to metformin-induced cell death. Conversely, overexpressing NAMPT in HEK-293 (293) cells causes the cells to be more resistant to metformin's growth inhibitory effects. The addition of a NAMPT activator also decreased the sensitivity of MCF7 cells to metformin, while the NAMPT activator, P7C3, protects against metformin-induced cytotoxicity.

Conclusions

Depletion of cellular NAD+ is a key aspect of sensitivity of cancer cells to the cytotoxic effects of metformin. NAMPT plays a key role in maintaining sufficient levels of NAD+, and cells that express elevated levels of NAMPT are resistant to killing by metformin.

A blast from the past: To tame time with metformin

The strong evidence of metformin use in subjects affected by type 2 diabetes (T2DM) on health outcomes, together with data from pre-clinical studies, has led the gerontological research to study the therapeutic potential of such a drug as a slow-aging strategy. However, despite clinical use for over fifty years as an anti-diabetic drug, the mechanisms of action beyond glycemic control remain unclear. In this review, we have deeply examined the literature, doing a narrative review from the metformin story, through mechanisms of action to slow down aging potential, from lower organisms to humans. Based on the available evidence, we conclude that metformin, as shown in lower organisms and mice, may be effective in humans' longevity. A complete analysis and follow-up of ongoing clinical trials may provide more definitive answers as to whether metformin should be promoted beyond its use to treat T2DM as a drug that enhances both healthspan and lifespan.

Diabetes medications and risk of HCC

Type 2 diabetes mellitus is a recognized risk factor for HCC in patients with liver disease, independent from the etiology of their liver disease. Hence, prevention and treatment of type 2 diabetes mellitus and its underlying cause, insulin resistance, should be considered a treatment target for patients with liver disease. The drug armamentarium for diabetes is wide and consists of agents with insulin-sensitizing activity, agents that stimulate insulin secretion, insulin itself, and agents that reduce gastrointestinal and urinary glucose absorption. From an endocrinology perspective, the main goal of treatment is the achievement of euglycemia; however, in patients at risk of, or with known underlying liver disease, the choice of diabetic medication as it relates to potential hepatic carcinogenesis remains complex and should be carefully considered. In the last decade, increasing evidence has suggested that metformin may reduce the risk of HCC, whereas evidence for other classes of diabetic medications, particularly some of the newer agents including the sodium glucose cotransporter-2 inhibitors and glucagon-like peptide-1 receptor agonists, is fewer and often inconsistent. In this review, we aim to summarize the current evidence on the potential effects of the most widely used diabetic agents on liver cancer tumorigenesis.

Second malignant neoplasms in lymphomas, secondary lymphomas and lymphomas in metabolic disorders/diseases

With inconsistent findings, evidence has been obtained in recent years that metabolic disorders are closely associated with the development of lymphomas. Studies and multiple analyses have been published also indicating that some solid tumor survivors develop a secondary lymphoma, whereas some lymphoma survivors subsequently develop a second malignant neoplasm (SMN), particularly solid tumors. An interaction between the multiple etiologic factors such as genetic factors and late effects of cancer therapy may play an important role contributing to the carcinogenesis in patients with metabolic diseases or with a primary cancer. In this review, we summarize the current knowledge of the multiple etiologic factors for lymphomagenesis, focusing on the SMN in lymphoma, secondary lymphomas in primary cancers, and the lymphomas associated to metabolic disorders/diseases, which have been received less attention previously. Further, we also review the data of coexistence of lymphomas and hepatocellular carcinoma (HCC) in patients with infection of hepatitis C virus and hepatitis B virus.

Correlations between circulating methylmalonic acid levels and all-cause and cause-specific mortality among patients with diabetes

Aims

Evidence regarding serum methylmalonic acid (MMA) levels and mortality in individuals with diabetes is limited. This study aimed to evaluate the correlation between MMA and all-cause and cause-specific deaths in patients with diabetes.

Materials and methods

This is a population-based cohort study based on data from both the National Health and Nutrition Examination Survey (NHANES) and National Death Index from 1999 to 2014. We assessed the association of serum MMA concentrations with mortality using Cox proportional hazard models after adjusting for lifestyle, demographic factors, and comorbidities.

Results

Among the 3,097 participants, 843 mortalities occurred during a median follow-up of 4.42 years. There were 242 deaths due to cardiovascular disease (CVD) and 131 cancer-associated deaths. After multivariate adjustment, elevated serum MMA levels were markedly correlated with a high risk of all-cause, CVD-, and cancer-related deaths. Each one-unit increase in the natural log-transformed MMA level correlated with increased risk of all-cause mortality (2.652 times), CVD mortality risk (3.153 times), and cancer-related mortality risk (4.514). Hazard ratios (95% confidence intervals [CIs]) after comparing participants with MMA &lt; 120 and ≥250 nmol/L were 2.177 (1.421–3.336) for all-cause mortality, 3.560 (1.809–7.004) for CVD mortality, and 4.244 (1.537–11.721) for cancer mortality.

Conclusion

Higher serum MMA levels were significantly associated with higher all-cause, CVD, and cancer mortality. These findings suggest that maintaining lower MMA status may lower mortality risk in individuals with diabetes.

Treat more than heat-New therapeutic implications of Cimicifuga racemosa through AMPK-dependent metabolic effects

BACKGROUND

Cimicifuga racemosa extracts (CRE) have obtained a "well-established use status" in the treatment of postmenopausal (i.e., climacteric) complaints, which predominantly include vasomotor symptoms such as hot flushes and sweating, as well as nervousness, irritability, and metabolic changes. Although characteristic postmenopausal complaints are known for a very long time and the beneficial effects of CRE on climacteric symptoms are well accepted, both the pathophysiology of postmenopausal symptoms and the mechanism of action of CREs are not yet fully understood. In particular, current hypotheses suggest that changes in the α-adrenergic and serotonergic signaling pathways secondary to estrogen depletion are responsible for the development of hot flushes.

PURPOSE

Some of the symptoms associated with menopause cannot be explained by these hypotheses. Therefore, we attempted to extend our classic understanding of menopause by integrating of partly age-related metabolic impairments.

METHODS

A comprehensive literature survey was performed using the PubMed database for articles published through September 2021. The following search terms were used: (cimicifuga OR AMPK) AND (hot flush* OR hot flash* OR menopaus* OR osteoporos* OR cancer OR antioxida* OR cardiovasc*). No limits were set with respect to language, and the references cited in the articles retrieved were used to identify additional publications.

RESULTS

We found that menopause is a manifestation of the general aging process, with specific metabolic changes that aggravate menopausal symptoms, which are accelerated by estrogen depletion and associated neurotransmitter dysregulation. Cimicifuga extracts with their metabolic effects mitigate climacteric symptoms but may also modulate the aging process itself. Central to these effects are effects of CRE on the metabolic key regulator, the AMP-activated protein kinase (AMPK).

CONCLUSIONS

As an extension of this effect dimension, other off-label indications may appear attractive in the sense of repurposing of this herbal treatment.

Family history, obesity, urological factors and diabetic medications and their associations with risk of prostate cancer diagnosis in a large prospective study

Background

Prostate cancer (PC) aetiology is unclear. PC risk was examined in relation to several factors in a large population-based prospective study.

Methods

Male participants were from Sax Institute’s 45 and Up Study (Australia) recruited between 2006 and 2009. Questionnaire and linked administrative health data from the Centre for Health Record Linkage and Services Australia were used to identify incident PC, healthcare utilisations, Prostate Specific Antigen (PSA) testing reimbursements and dispensing of metformin and benign prostatic hyperplasia (BPH) prescriptions. Multivariable Cox and Joint Cox regression analyses were used to examine associations by cancer spread, adjusting for various confounders.

Results

Of 107,706 eligible men, 4257 developed incident PC up to end 2013. Risk of PC diagnosis increased with: PC family history (versus no family history of cancer; HR_adjusted = 1.36; 95% CI:1.21–1.52); father and brother(s) diagnosed with PC (versus cancer-free family history; HR_adjusted = 2.20; 95% CI:1.61–2.99); severe lower-urinary-tract symptoms (versus mild; HR_adjusted = 1.77; 95% CI:1.53–2.04) and vasectomy (versus none; HR_adjusted = 1.08; 95% CI:1.00–1.16). PC risk decreased with dispensed prescriptions (versus none) for BPH (HR_adjusted = 0.76; 95% CI:0.69–0.85) and metformin (HR_adjusted = 0.57; 95% CI:0.48–0.68). Advanced PC risk increased with vasectomy (HR_adjusted = 1.28; 95% CI:1.06–1.55) and being obese (versus normal weight; HR_adjusted = 1.31; 95% CI:1.01–1.69).

Conclusion

Vasectomy and obesity are associated with an increased risk of advanced PC. The reduced risk of localised and advanced PC associated with BPH, and diabetes prescriptions warrants investigation.

2-Methoxy-1,4-naphthoquinone (MNQ) regulates cancer key genes of MAPK, PI3K, and NF-κB pathways in Raji cells

2-Methoxy-1,4-naphthoquinone (MNQ) has been shown to cause cytotoxic towards various cancer cell lines. This study is designed to investigate the regulatory effect of MNQ on the key cancer genes in mitogen-activated protein kinase, phosphoinositide 3-kinase, and nuclear factor кB signaling pathways. The expression levels of the genes were compared at different time point using polymerase chain reaction arrays and Ingenuity Pathway Analysis was performed to identify gene networks that are most significant to key cancer genes. A total of 43 differentially expressed genes were identified with 21 up-regulated and 22 down-regulated genes. Up-regulated genes were involved in apoptosis, cell cycle and act as tumor suppressor while down-regulated genes were involved in anti-apoptosis, angiogenesis, cell cycle and act as transcription factor as well as proto-oncogenes. MNQ exhibited multiple regulatory effects on the cancer key genes that targeting at cell proliferation, cell differentiation, cell transformation, apoptosis, reduce inflammatory responses, inhibits angiogenesis and metastasis.

Antidiabetic Medications and the Risk of Prostate Cancer in Patients with Diabetes Mellitus: A Systematic Review and Meta-analysis

BACKGROUND

Antidiabetic medications (ADMs) may modify prostate cancer (PCa) risk in patients with diabetes mellitus (DM). Accordingly, the current study assessed the possible associations between ADMs and the risk of PCa in diabetics.

METHODS

A systematic literature search (PubMed, Embase and Cochrane Library) identified studies evaluating the associations between ADMs and incidence of PCa. A meta-analysis followed PRISMA was performed using odds ratio (OR) with 95% confidence interval (CI) as effect measures.

RESULTS

In total of 47 studies involving 3,094,152 patients with diabetes were included. Results of meta-analysis of the observational studies suggested no significant association between metformin, thiazolidinediones, sulfonylureas, insulin or dipeptidyl peptidase-4 inhibitors administration and the risk of PCa (All p-values > 0.05). Separate analysis of randomized controlled trials (RCTs) revealed a significant reduction in PCa risk with thiazolidinediones (OR = 0.55, p = 0.04) or glucagon-like peptide-1 receptor agonists (GLP-1RA) administration (OR = 0.53, p = 0.006), whereas no significant association was found in SGLT2 inhibitors (p = 0.3).

CONCLUSION

Thiazolidinediones or GLP-1RA administration may have benefits in PCa based on RCTs, however, further research is needed to confirm these findings.

Effects of Behavioral Weight Loss and Metformin on IGFs in Cancer Survivors: A Randomized Trial

CONTEXT

Higher levels of insulin-like growth factor-1 (IGF-1) are associated with increased risk of cancers and higher mortality. Therapies that reduce IGF-1 have considerable appeal as means to prevent recurrence.

DESIGN

Randomized, 3-parallel-arm controlled clinical trial.

INTERVENTIONS AND OUTCOMES

Cancer survivors with overweight or obesity were randomized to (1) self-directed weight loss (comparison), (2) coach-directed weight loss, or (3) metformin treatment. Main outcomes were changes in IGF-1 and IGF-1:IGFBP3 molar ratio at 6 months. The trial duration was 12 months.

RESULTS

Of the 121 randomized participants, 79% were women, 46% were African Americans, and the mean age was 60 years. At baseline, the average body mass index was 35 kg/m2; mean IGF-1 was 72.9 (SD, 21.7) ng/mL; and mean IGF1:IGFBP3 molar ratio was 0.17 (SD, 0.05). At 6 months, weight changes were -1.0% (P = 0.07), -4.2% (P < 0.0001), and -2.8% (P < 0.0001) in self-directed, coach-directed, and metformin groups, respectively. Compared with the self-directed group, participants in metformin had significant decreases on IGF-1 (mean difference in change: -5.50 ng/mL, P = 0.02) and IGF1:IGFBP3 molar ratio (mean difference in change: -0.0119, P = 0.011) at 3 months. The significant decrease of IGF-1 remained in participants with obesity at 6 months (mean difference in change: -7.2 ng/mL; 95% CI: -13.3 to -1.1), but not in participants with overweight (P for interaction = 0.045). There were no significant differences in changes between the coach-directed and self-directed groups. There were no differences in outcomes at 12 months.

CONCLUSIONS

In cancer survivors with obesity, metformin may have a short-term effect on IGF-1 reduction that wanes over time.

A dual-functional biomimetic-mineralized nanoplatform for glucose detection and therapy with cancer cells in vitro

Glucose detection is a crucial topic in the diagnosis of numerous diseases, such as hypoglycemia or diabetes mellitus. Research indicates that people with diabetes mellitus are at a higher risk of developing various types of cancer. A nanoplatform that combines both diabetes diagnosis and cancer therapy might be regarded as a more effective way to solve the above-mentioned problem. However, none of the known sensors has a smart strategy that can work as a fluorescent glucose sensor and a cancer therapeutic platform simultaneously. Here, we developed a pH responsive biomimetic-mineralized nanoplatform (denoted as CaCO3-PDA@DOX-GOx) for glucose detection in serum samples and applied it to treat the tumor cells combined chemotherapy with the starvation therapy in vitro. Doxorubicin (DOX) and glucose oxidase (GOx) were loaded through the mesoporous CaCO3-PDA nanoparticles (m-CaCO3-PDA NPs). The fluorescence of DOX is quenched as a result of fluorescence resonance energy transfer (FRET) caused by the broad absorption of m-CaCO3-PDA NPs. The nanoplatform would recover fluorescence under lower pH values due to the catalytic reaction of GOx with glucose or tumor microenvironment (TME), which leads to the elimination of FRET. Its application as a glucose sensor is indicated with a linear relationship in the range of 0.01-1.0 mM of glucose and limit of detection is calculated by 6 μM. This nanoplatform also has a TME-responsive antitumor effect and fluorescence imaging functionality, which provide a new idea for cancer therapy together with glucose monitoring in diabetes.

Diabetes and Cancer: Metabolic Association, Therapeutic Challenges, and the Role of Natural Products

Cancer is considered the second leading cause of death worldwide and in 2018 it was responsible for approximately 9.6 million deaths. Globally, about one in six deaths are caused by cancer. A strong correlation was found between diabetes mellitus and carcinogenesis with the most evident correlation was with type 2 diabetes mellitus (T2DM). Research has proven that elevated blood glucose levels take part in cell proliferation and cancer cell progression. However, limited studies were conducted to evaluate the efficiency of conventional therapies in diabetic cancer patients. In this review, the correlation between cancer and diabetes will be discussed and the mechanisms by which the two diseases interact with each other, as well as the therapeutics challenges in treating patients with diabetes and cancer with possible solutions to overcome these challenges. Natural products targeting both diseases were discussed with detailed mechanisms of action. This review will provide a solid base for researchers and physicians to test natural products as adjuvant alternative therapies to treat cancer in diabetic patients.

Plasma metals and cancer incidence in patients with type 2 diabetes

There is limited evidence on the relationships between plasma levels of multiple metals and risk of incident cancer in patients with type 2 diabetes mellitus (T2DM). We examined the associations between plasma levels of 12 metals (iron, copper, zinc, selenium, chromium, manganese, molybdenum, cobalt, nickel, arsenic, cadmium, and lead) and cancer risk in 4573 T2DM patients using Cox proportional hazards models. With a median follow-up of 10.2 years, 541 incident cancers were identified. The multiple-metals model revealed that each 1-SD increase in ln-transformed plasma copper (HR: 1.14; 95%CI: 1.02, 1.27) and lead (HR:1.20; 95%CI:1.03, 1.39) were significantly associated with increased cancer incidence while each 1-SD increase in ln-transformed plasma zinc (HR: 0.82; 95%CI: 0.71, 0.96) and chromium (HR: 0.88; 95%CI: 0.82, 0.94) were significantly associated with decreased cancer incidence. When all participants were further stratified into four subgroups by the quartile levels (Q1-4) of plasma metals, manganese showed significant positive associations with cancer incidence in the upper two quartiles (P trend = 0.003) while nickel showed significant negative associations with cancer incidence in Q2 and 4 groups (P trend = 0.033) compared with participants in Q1 group. Collectively, monitoring of metal levels in diabetic patients needs to be strengthened, which is of great significance for the prevention of incident cancer.

Genome-Scale CRISPR-Cas9 Transcriptional Activation Screening in Metformin Resistance Related Gene of Prostate Cancer

Metformin is a classic type II diabetes drug which possesses anti-tumor properties for various cancers. However, different cancers do not respond to metformin with the same effectiveness or acquire resistance. Thus, searching for vulnerabilities of metformin-resistant prostate cancer is a promising strategy to improve the therapeutic efficiency of the drug. A genome-scale CRISPR-Cas9 activation library search targeting 23,430 genes was conducted to identify the genes that confer resistance to metformin in prostate cancer cells. Candidate genes were selected by total reads of sgRNA and sgRNA diversity, and then a CCK8 assay was used to verify their resistance to metformin. Interestingly, we discovered that the activation of ECE1, ABCA12, BPY2, EEF1A1, RAD9A, and NIPSNAP1 contributed to in vitro resistance to metformin in DU145 and PC3 cell lines. Notably, a high level of RAD9A, with poor prognosis in PCa, was the most significant gene in the CCK8 assay. Furthermore, we discerned the tumor immune microenvironment with RAD9A expression by CIBERSORT. These results suggested that a high level of RAD9A may upregulate regulatory T cells to counterbalance metformin in the tumor immune microenvironment.

Relationship between metformin therapy and risk of colorectal cancer in patients with diabetes mellitus: a meta-analysis

OBJECTIVE

At present, there are many studies on metformin and the risk of colorectal cancer in patients with diabetes, but the conclusions are contradictory. Our aim is to comprehensively collect the published literature and systematically evaluate the relationship between metformin and the risk of colorectal cancer in patients with diabetes.

METHODS

We systematically searched the MEDLINE, EMBASE, and CENTRAL databases up to March 2020. We adopted adjusted estimates and their 95% confidence intervals (CI) to calculate summary effect estimates using either a fixed-effects or a random-effects model.

RESULTS

A total of 17 articles were included in this study, with a total of 1,092,074 patients with diabetes. Meta-analysis of observational studies showed that metformin treatment could significantly reduce the incidence of colorectal cancer in diabetic patients (adjusted RR = 0.884, 95%CI = 0.829-0.943), and there was heterogeneity between studies (p = 0.013, I² = 47.9%). Subgroup analysis showed that metformin treatment was significantly associated with a significantly reduced risk of colorectal cancer in diabetics in America and Europe (adjusted RR = 0.852, 95%CI = 0.786-0.924; adjusted RR = 0.900, 95%CI = 0.845-0.958). Patients with diabetes treated with metformin had a significantly lower risk of colorectal cancer compared with patients who had never been treated with metformin or sulfonamide monotherapy (adjusted RR = 0.863, 95%CI = 0.776-0.960; adjusted RR = 0.911, 95%CI = 0.882-0.941).

CONCLUSIONS

Metformin therapy is associated with a significantly reduced risk of colorectal disease in patients with diabetes, and it is necessary to conduct larger, more standardized clinical studies to verify this conclusion.

Healthcare utilization and direct medical cost in the years during and after cancer diagnosis in patients with type 2 diabetes mellitus

AIMS/INTRODUCTION

There is uncertainty about the direct medical costs of type 2 diabetes patients with cancers.

MATERIALS AND METHODS

A population-based retrospective cohort of 99,915 type 2 diabetes patients from the Hong Kong Hospital Authority between 2006 and 2017 was assembled. A total of 16,869 patients who had an initial cancer diagnosis after type 2 diabetes diagnosis were matched with 83,046 patients without cancer (controls) using a matching ratio of up to one-to-five propensity score-matching method. Patients were divided into four categories according to life expectancy. Healthcare service utilization and direct medical costs during the index year, subsequent years and mortality year were compared between patients with and without cancer in each category.

RESULTS

Medical costs of cancer patients in the index year ranged from $US27,533 for patients who died in <1 year to $US11,303 for those survived >3 years. Cancer patients had significantly greater expenditures than controls in the index year (all P < 0.001) and subsequent years ($US4,569 vs $US4,155, P < 0.001). Cancer patients also had greater costs in the year of death, and the difference was significant for patients who survived >3 years after the index year ($US32,558 vs $US28,260). For patients in both groups, patients who survived >3 years had significantly lower costs than those who died in <1 year. Costs incurred in the mortality year were greater than those in the index year and subsequent years. Hospitalization accounted for >90% of the medical costs for both groups in the mortality year.

CONCLUSIONS

Type 2 diabetes patients with cancers incurred greater medical costs in the diagnosis, ensuing and mortality years than type 2 diabetes patients without cancers.

Metformin administration during pregnancy attenuated the long-term maternal metabolic and cognitive impairments in a mouse model of gestational diabetes

Background: Gestational diabetes mellitus (GDM) is a metabolic disease that can have long-term adverse effects on the cognitive function of mothers. In our study, we explored the changes in metabolic health and cognitive function in mice of middle- and old- age after exposure to GDM, and whether metformin therapy during pregnancy provided long-term benefits.

Results: Mice with GDM demonstrated significant cognitive impairment in old age, which was associated with insulin resistance. Gestational metformin therapy was shown to increase insulin sensitivity and improve cognition. The ovarian aging rate was also accelerated in mice exposed to GDM during pregnancy, which may be related to fatty acid metabolism in the ovaries.

Conclusion: Treatment with metformin during pregnancy was shown to improve fatty acid metabolism in ovarian tissues.

Method: During pregnancy, mice were fed with a high-fat diet (GDM group) or a low-fat diet (Control group), and a third group received metformin while receiving a high-fat diet (Treatment group). At 12 months old, the mice completed an oral glucose tolerance test, insulin tolerance test, Morris water maze test, female sex hormones were measured, and metabolite profiles of tissue from the ovaries, hypothalamus, and pituitary glands were analysed using gas chromatography-mass spectrometry.

Metformin Ameliorates Oxidative Stress Induced by Diabetes Mellitus and Hepatocellular Carcinoma in Rats

Background

Several studies have found an association between Diabetes mellitus (DM) and an increased risk for hepatocellular carcinoma (HCC). Evidence suggests that Metformin (Met) may have a therapeutic and protective effect against both DM and HCC. Therefore, the aim of this study was to evaluate the antioxidant effect of Met against DM and HCC-induced oxidative stress in rat model.

Methods

Forty-two male albino rats were randomly divided into six groups. Group 1 (Gp1) was the control group, Gp2 received an intraperitoneal (i.p.) injection with streptozotocin (STZ), Gp3 was injected i.p. with diethyl nitrosamine (DEN), Gp4 received an oral administration of Met, Gp5 and Gp6 received the same injections as Gp2 and Gp3, respectively, then received an additional injection of Met. Oxidative stress biomarkers, including superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) and malondialdehyde (MDA), were examined. Furthermore, biochemical parameters including liver function tests were assessed. Histopathological and immunohistochemical alterations of the liver were also examined.

Results

Our results demonstrate that Gp2 and Gp3 had significant signs of liver dysfunction and had elevated levels of MDA and reduced levels of SOD, CAT, and GSH. Additionally, Gp2 and Gp3 showed significant alterations in the liver architecture shown by high PCNA and caspase-3 expression. In the Gp5 and Gp6, treatment with Met showed an improvement in liver function, oxidative stress biomarkers, and reduced histopathological changes in hepatocytes.

Conclusion

This study offers insight into the potential for Metformin as a novel therapeutic against the oxidative stress induced by DM or HCC.

A systematic analysis of natural α-glucosidase inhibitors from flavonoids of Radix scutellariae using ultrafiltration UPLC-TripleTOF-MS/MS and network pharmacology

BACKGROUND

Flavonoids from plant medicines are supposed to be viable alternatives for the treatment of type 2 diabetes (T2D) as less toxicity and side effects. Radix scutellariae (RS) is a widely used traditional medicine in Asia. It has shown great potential in the research of T2D. However, the pharmacological actions remain obscured due to the complex chemical nature of plant medicines.

METHODS

In the present study, a systematic method combining ultrafiltration UPLC-TripleTOF-MS/MS and network pharmacology was developed to screen α-glucosidase inhibitors from flavonoids of RS, and explore the underlying mechanism for the treatment of T2D.

RESULTS

The n-butanol part of ethanol extract from RS showed a strong α-glucosidase inhibition activity (90.55%, IC50 0.551 mg/mL) against positive control acarbose (90.59%, IC50 1.079 mg/mL). A total of 32 kinds of flavonoids were identified from the extract, and their ESI-MS/MS behaviors were elucidated. Thirteen compounds were screened as α-glucosidase inhibitors, including viscidulin III, 2',3,5,6',7-pentahydroxyflavanone, and so on. A compound-target-pathway (CTP) network was constructed by integrating these α-glucosidase inhibitors, target proteins, and related pathways. This network exhibited an uneven distribution and approximate scale-free property. Chrysin (k = 87), 5,8,2'-trihydroxy-7-methoxyflavone (k = 21) and wogonin (k = 20) were selected as the main active constituents with much higher degree values. A protein-protein interaction (PPI) weighted network was built for target proteins of these α-glucosidase inhibitors and drug targets of T2D. PPARG (Cd = 0.165, Cb = 0.232, Cc = 0.401), ACACB (Cd = 0.155, Cb = 0.184, Cc = 0.318), NFKB1 (Cd = 0.233, Cb = 0.161, Cc = 0.431), and PGH2 (Cd = 0.194, Cb = 0.157, Cc = 0.427) exhibited as key targets with the highest scores of centrality indices. Furthermore, a core subnetwork was extracted from the CTP and PPI weighted network. Type II diabetes mellitus (hsa04930) and PPAR signaling pathway (hsa03320) were confirmed as the critical pathways.

CONCLUSIONS

These results improved current understanding of natural flavonoids on the treatment of T2D. The combination of ultrafiltration UPLC-TripleTOF-MS/MS and network pharmacology provides a novel strategy for the research of plant medicines and complex diseases.

How treatments with endocrine and metabolic drugs influence pituitary cell function

A variety of endocrine and metabolic signals regulate pituitary cell function acting through the hypothalamus-pituitary neuroendocrine axes or directly at the pituitary level. The underlying intracellular transduction mechanisms in pituitary cells are still debated. AMP-activated protein kinase (AMPK) functions as a cellular sensor of low energy stores in all mammalian cells and promotes adaptive changes in response to calorie restriction. It is also regarded as a target for therapy of proliferative disorders. Various hormones and drugs can promote tissue-specific activation or inhibition of AMPK by enhancing or inhibiting AMPK phosphorylation, respectively. This review explores the preclinical studies published in the last decade that investigate the role of AMP-activated protein kinase in the intracellular transduction pathways downstream of endocrine and metabolic signals or drugs affecting pituitary cell function, and its role as a target for drug therapy of pituitary proliferative disorders. The effects of the hypoglycemic agent metformin, which is an indirect AMPK activator, are discussed. The multiple effects of metformin on cell metabolism and cell signalling and ultimately on cell function may be either dependent or independent of AMPK. The in vitro effects of metformin may also help highlighting differences in metabolic requirements between pituitary adenomatous cells and normal cells.

Hyperglycemia decreases anti-cancer efficiency of Adriamycin via AMPK pathway

The authors and journal apologise for an error in the above paper, which appeared in volume 25 part 11, pages 955–966. The error relates to the artwork of Fig. 5 on page 963, in which the blots given in panel E were mistakenly replicated in panel F.

Diabetes and its Potential Impact on Head and Neck Oncogenesis

In recent years, the incidence of diabetes mellitus and cancer has increased sharply; indeed, these have become the two most important diseases threatening health and survival. Head and neck (HN) tumors are the sixth most common malignancies in humans. Numerous studies have shown that there are many common risk factors for diabetes mellitus and HN squamous cell carcinoma, including advanced age, poor diet and lifestyle, and environmental factors. However, the mechanism linking the two diseases has not been identified. A number of studies have shown that diabetes affects the development, metastasis, and prognosis of HN cancer, potentially through the associated hyperglycemia, hyperinsulinemia and insulin resistance, or chronic inflammation. More recent studies show that metformin, the first-line drug for the treatment of type 2 diabetes, can significantly reduce the risk of HN tumor development and reduce mortality in diabetic patients. Here, we review recent progress in the study of the relationship between diabetes mellitus and HN carcinogenesis, and its potential mechanisms, in order to provide a scientific basis for the early diagnosis and effective treatment of these diseases.

Incident cancer risk in dipeptidyl peptidase-4 inhibitor-treated patients with type 2 diabetes mellitus

Objective

It is known that patients with diabetes are susceptible to cancer development due to long-standing diabetic conditions. This study aimed to investigate new-onset cancer risk associated with dipeptidyl peptidase-4 (DPP-4) inhibitors as compared to metformin, the first-line antidiabetic agent with promising anticancer activity, in patients with type 2 diabetes mellitus (T2DM).

Methods

A retrospective cohort study of adult T2DM patients was performed at a tertiary care hospital in Korea. Patients who received comparison therapies during 2008–2017 were propensity score (PS)-matched in a 1:1 ratio either to the DPP-4 inhibitors group or to the metformin group in accordance with their primary antidiabetic therapy.

Results

A total of 1538 patients (769 in each group) were found eligible for study entry. Although the rate of newly diagnosed malignancy, irrespective of specific sites or types, was numerically less frequent in the DPP-4 inhibitors group, the difference in overall cancer risk between groups was not statistically significant (HR=1.00, 95% CI=0.56–1.80, P=0.998). The PS-matched patients were further stratified by relevant patient factors and diabetes severity. No signal of increased risk of malignant complications among DPP-4 inhibitor-receiving diabetic patients was detected in any of the individual strata, nor in the subgroup patients where insulin-exposed patients were excluded from study analyses in consideration of its carcinogenic properties. Patient death or incident pancreatitis events were seldom encountered in both treatment groups; hence such risks were assessed as negligible with the use of either antidiabetic therapy.

Conclusion

This PS-matched cohort study demonstrated no elevated risk of malignant complications with DPP-4 inhibitor treatment relative to metformin treatment among T2DM patients, irrespective of patient sex, age, comorbid conditions, and diabetes severity status. Similar results were confirmed in the subgroup analyses where a potential confounding effect due to the between-group disparity in insulin co-therapy was eliminated by excluding insulin-exposed patients from risk assessments.

Metformin and Breast Cancer: Molecular Targets

Metformin has been the first-line drug for the treatment of type II diabetes mellitus for decades, being presently the most widely prescribed antihyperglycemic drug. Retrospective studies associate the use of metformin with a reduction in cancer incidence and cancer-related death. However, despite extensive research about the molecular effects of metformin in cancer cells, its mode of action remains controversial. The major molecular targets of metformin include complex I of the mitochondrial electron transport chain, adenosine monophosphate (AMP)-activated protein kinase (AMPK), and mechanistic target of rapamycin complex 1 (mTORC1), but AMPK-independent effects of metformin have also been described. Breast cancer is one of the leading causes of cancer-related morbidity and mortality among women worldwide. Several studies have reinforced a link between breast cancer risk and diabetes. Moreover, metformin significantly reduces breast cancer risk, compared to patients who are not using metformin and is independent of diabetes status. In this review, we summarize the current molecular evidence to elucidate metformin's mode of action against breast cancer cells.

Metformin Treatment Suppresses Melanoma Cell Growth and Motility Through Modulation of microRNA Expression

Melanoma is a highly aggressive cancer with high mortality in advanced stages. Metformin is an oral biguanide drug used for diabetes and has demonstrated positive effects on cancer prevention and treatment. Herein, we found that metformin significantly suppressed melanoma cancer cell motility and growth through inducing cell cycle arrest at the G2/M phase and promoting cell apoptosis. Using the next-generation sequencing approach, we identified three upregulated microRNAs (miRNA; miR-192-5p, miR-584-3p, and miR-1246) in melanoma cells treated with metformin. Among these, we examined the roles of miR-192-5p and miR-584-3p and discovered that they significantly suppressed melanoma cell motility. Furthermore, they inhibited melanoma cell growth through destroying cell cycle progression and inducing cell apoptosis. Using microarray and bioinformatics approaches for identifying putative target genes, Epidermal growth factor (EGF) containing fibulin-like extracellular matrix protein 1 (EFEMP1) gene for miR-192-5p and an isoform of the secretory carrier membrane proteins (SCAMP3) gene for miR-584-3p could be silenced through targeting their 3′UTR region directly. EFEMP1 and SCAMP3 knockdown significantly suppressed melanoma cell growth, but only EFEMP1 knockdown inhibited its motility abilities. Our findings indicated that miR-192-5p and miR-584-3p might contribute to metformin-induced growth and motility suppression in melanoma cells through silencing their target genes EFEMP1 and SCAMP3.

Metformin Counteracts HCC Progression and Metastasis Enhancing KLF6/p21 Expression and Downregulating the IGF Axis

BACKGROUND AND AIMS

Hepatocellular carcinoma (HCC) is the common tumor of the liver. Unfortunately, most HCC seem to be resistant to conventional chemotherapy and radiotherapy. The poor efficacy of antitumor agents is also due, at least in part, to the inefficient drug delivery and metabolism exerted by the steatotic/cirrhotic liver that hosts the tumor. Thus, novel approaches in chemotherapy may be needed to improve the survival rate in patients with HCC. Metformin (METF) has been found to lower HCC risk; however, the mechanisms by which METF performs its anticancer activity are not completely elucidated. Previous studies have showed METF action on growth inhibition in the liver in a dose/time-dependent manner and its antitumor role by targeting multiple pathways. We investigated molecular effects of METF in an in vitro human hepatoma model (HepG2), studying cell cycle regulators, tumorigenesis markers, and insulin-like growth factor (IGF) axis regulation.

MATERIALS AND METHODS

HepG2 cells were treated with METF (400 μM) for 24, 48, and 72 hours. METF action on cell cycle progression and cellular pathways involved in metabolism regulation was evaluated by gene expression analysis, immunofluorescence, and Western blot assay.

RESULTS

By assessing HepG2 cell viability, METF significantly decreased growth cell capacity raising KLF6/p21 protein content. Moreover, METF ameliorated the cancer microenvironment reducing cellular lipid drop accumulation and promoting AMPK activity. The overexpression of IGF-II molecule and the IGF-I receptor that plays a main role in HCC progression was counteracted by METF. Furthermore, the protein content of HCC principal tumor markers, CK19 and OPN, linked to the metastasis process was significantly reduced by METF stimulus.

CONCLUSION

Our data show that METF could suppress HepG2 proliferation, through induction of cell cycle arrest at the G0/G1 phase. In addition, METF effect on the cancer microenvironment and on the IGF axis leads to the development of new METF therapeutic use in HCC treatment.

Serum insulin level, HOMA-IR and prostate cancer risk: A systematic review and meta-analysis

AIMS

This meta-analysis study was performed to assess serum insulin level and insulin resistance status in prostate cancer patients in observational studies.

MATERIALS AND METHODS

A systematic literature search was performed for observational studies in Scopus, PubMed, Ovid and ISI Web of Science up to July 2017.

RESULTS

From 2070 publication were searched firstly, only 10 studies with 9 and 6 arms included for the meta-analysis assessing serum insulin level and HOMA-IR status in prostate cancer patients, respectively. Pooled effects analysis showed that the Fasting insulin level was significantly higher in men with prostate cancer compared to control group (WMD = 2.12 μ IU/ml, 95%CI; 0.26, 3.99; P = 0.02). Sub-group analysis showed that the elevation in serum insulin level takes place only in patients with ages more than 65 years old (WMD = 3.88 μ IU/ml, 95%CI; 2.28, 5.48; P < 0.001). HOMA-IR was no significantly different between study groups. However, the difference got statistically significant after sub-grouping patients based on their age (WMD = 1.37, 95% CI; 0.61, 2.12; P < 0.001).

CONCLUSION

In conclusion, the results of this meta-analysis study showed higher fasting serum insulin and HOMA-IR levels especially in patients with ages more than 65 years..

Effect of different glucose-lowering therapies on cancer incidence in type 2 diabetes: An observational population-based study

AIM

To assess the effect of metformin on cancer incidence in type 2 diabetes (T2DM), considering possible interactions with other glucose-lowering drugs and diabetes duration.

METHODS

Study cohort included diabetes patients aged 20-84 on December 2009, still alive and resident in Reggio Emilia province as of December 2011. Drug exposure was assessed for 2009-2011; subjects taking metformin continuously, with or without other hypoglycaemic drugs, were compared to subjects on diet-only therapy. The cohort was followed up from 2012 to 2014 through the cancer registry. Age- and sex-adjusted incidence rate ratios (IRRs) were computed using Poisson regression models for all sites, lung, breast, liver, colorectal, prostate and pancreatic cancer.

RESULTS

The cohort includes 17,026 people with T2DM, 7460 taking metformin. 887 cancers occurred during follow-up, 348 among metformin users. Cancer risk was similar in T2DM patients using metformin and those on diet-only. The risk for prostate (IRR = 0.65; 95%CI:0.36; 1.17), liver (IRR = 0.82; 95%CI:0.36; 1.85) and breast (IRR = 0.77; 95%CI:0.43; 1.40) cancers only was slightly reduced; for lung (IRR = 1.52; 95%CI:0.92; 2.50), pancreas (IRR = 1.51; 95%CI:0.59:3.89) and colon-rectum (IRR = 1.71; 95%CI:0.94; 3.08) the risk was slightly increased.

CONCLUSIONS

There is no evidence of antitumor effect of metformin. A possible decrease only for breast, liver and prostate cancer, is compatible with random fluctuations.

Chronic hyperglycemia mediated physiological alteration and metabolic distortion leads to organ dysfunction, infection, cancer progression and other pathophysiological consequences: An update on glucose toxicity

Chronic exposure of glucose rich environment creates several physiological and pathophysiological changes. There are several pathways by which hyperglycemia exacerbate its toxic effect on cells, tissues and organ systems. Hyperglycemia can induce oxidative stress, upsurge polyol pathway, activate protein kinase C (PKC), enhance hexosamine biosynthetic pathway (HBP), promote the formation of advanced glycation end-products (AGEs) and finally alters gene expressions. Prolonged hyperglycemic condition leads to severe diabetic condition by damaging the pancreatic β-cell and inducing insulin resistance. Numerous complications have been associated with diabetes, thus it has become a major health issue in the 21st century and has received serious attention. Dysregulation in the cardiovascular and reproductive systems along with nephropathy, retinopathy, neuropathy, diabetic foot ulcer may arise in the advanced stages of diabetes. High glucose level also encourages proliferation of cancer cells, development of osteoarthritis and potentiates a suitable environment for infections. This review culminates how elevated glucose level carries out its toxicity in cells, metabolic distortion along with organ dysfunction and elucidates the complications associated with chronic hyperglycemia.

Effects of metformin on cell growth and AMPK activity in pituitary adenoma cell cultures, focusing on the interaction with adenylyl cyclase activating signals

For a few years we have been investigating AMP-activated protein kinase (AMPK) as a target for drug therapy of GH-secreting pituitary adenomas. Aim of this study was to investigate the direct effects of metformin, which causes AMPK activation in different cell types, on rat pituitary adenoma cell growth and on related cell signalling pathways. Our results suggest that metformin can exert a growth-inhibitory activity in rat pituitary tumor cells mediated by AMPK activation, although multiple mechanisms are most likely involved. Membrane proteins, including growth factor receptors, are valuable targets of AMPK. The inhibition of the mTOR-p70S6 kinase signalling pathway plays a role in the suppressive effect of metformin on pituitary tumor cell growth. Metformin did not affect the MTT reduction activity in energetic stress conditions. Finally, metformin was still able to induce AMPK activation and to inhibit cell growth in cells treated with forskolin and in transfected cells overexpressing GHRH-receptor and treated with GHRH. Hence, adenylyl cyclase over-activation does not account for the lack of response of some human pituitary tumors to AMPK-activating compounds in vitro.

Selenadiazole derivatives antagonize hyperglycemia-induced drug resistance in breast cancer cells by activation of AMPK pathways

Hyperglycemia is an important factor for chemoresistance of breast cancer patients with diabetes. In the present study, a novel selenadiazole derivative has been evaluated and found to be able to antagonize the doxorubicin (DOX) resistance of MCF-7 cells under simulated diabetes conditions. Hyperglycemia promotes the proliferation, invasion and migration of MCF-7 cells through activation of ERK and AKT pathways, which could be inhibited by the synthetic selenadiazole derivative. The antitumor effects of the selenadiazole derivative were attributed to its ability to activate AMPK pathways. Furthermore, the high lipophilicity (log P = 1.9) of the synthetic selenadiazole derivative facilitated its uptake by cancer cells and subsequently potentiated the cellular uptake of DOX, leading to a strong enhancment of the antiproliferative activity of DOX on MCF-7 cells by induction of apoptosis. The apoptosis was initiated by the ROS overproduction induced by the cooperation of the selenadiazole derivative and DOX. The excessive ROS then caused damage to DNA, which upregulated the expression of proapoptosis Bcl-2 family proteins and led to fragmentation of mitochondria, which finally caused apoptosis of the cancer cells. Taken together, this study provides a rational strategy for using selenadiazole derivatives to overcome hyperglycemia-induced drug resistance in breast cancer by activation of AMPK-mediated pathways.

Effect of hypoglycemic agents on survival outcomes of lung cancer patients with diabetes mellitus: A meta-analysis

BACKGROUND

To assess the association between hypoglycemic agents and prognosis of lung cancer patients with diabetes.

METHODS

A comprehensive literature search was performed in PubMed, Web of Science, Embase, and Cochrane Library until May 2017. The search yielded 2593 unique citations, of which 18 articles met inclusion criteria. The hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated by a fixed-effects or random-effects model.

RESULTS

The pooled HRs favoring metformin users were 0.77 for overall survival (OS) (n = 15, 95% CI: 0.68-0.86) and 0.50 for disease-free survival (n = 5, 95% CI: 0.39-0.64). One study assessed the relationship between metformin and cancer-specific survival (CSS), reporting no significant results. No significant association between insulin and OS (n = 2, HR: 0.95, 95% CI: 0.79-1.13) or CSS (n = 2, HR: 1.03, 95% CI: 0.76-1.41) was noted. One study evaluated association of sulfonylureas with lung cancer survival and reported no clinical benefit (HR: 1.10, 95% CI: 0.87-1.40). One study reported no association of thiazolidinediones with lung cancer survival (HR: 1.04, 95% CI: 0.65-1.66).

CONCLUSIONS

This meta-analysis demonstrated that metformin exposure might improve survival outcomes in lung cancer patients with diabetes.

Fasting Blood Glucose Level in Locally Advanced Non-Small Cell Lung Cancer: a New Prognostic Factor?

Hyperglycemia may lead to proliferation, invasion, apoptosis inhibition, migration, and eventually metastasis of cancer cells by several mechanisms. In this study, the effect of hyperglycemia on overall survival (OS), disease-free survival (DFS), and locoregional recurrence (LRR) was investigated in NSCLC. One stage IIIA-IIIB NSCLC patient treated with chemoradiotherapy between 2010 and 2015 was enrolled. Fasting blood glucose (FBG) levels were recorded in pre-treatment, treatment, and post-treatment periods. Median age was 54 years (51-62). Fifty-two patients had squamous cell carcinoma (SCC); 19 had adenocarcinoma. Median follow-up was 19 (11-30), median survival was 19 (13-24), and DFS was 9 (7-11) months. Diabetic patients had shorter survival than non-diabetics 12 (95%CI, 10-14) vs. 25 months (95%CI,18-32), p = 0.005. Number of patients with LRR was also higher in diabetics compared to non-diabetics (8/12 vs. 11/37, p = 0.039). OS was shorter in patients with hyperglycemic-FBG and diabetic-FBG levels in pre-treatment period (log-rank p = 0.03 and 0.023, respectively). Diabetic-FBG level in pre-treatment period was found to be the only independent risk factor for survival. In subgroup analysis, these differences were apparent in SCC (log-rank p = 0.009 for hyperglicemic, log-rank p = 0.017 for diabetic-FBG). LRR was 68% in patients with diabetic-FBG, 36.5% in patients with non-diabetic-FBG in post-treatment period (p = 0.015). Patients with LRR had significantly higher median FBG value in post-treatment period compared to non-relapsing patients, 138 mg/dL (119-228) and 111 mg/dL (99-164), respectively (p = 0.022). The patients with hyperglycemic and diabetic-FBG levels in pre-treatment period had shorter survival compared to normoglycemic ones. The patients with diabetic-FBG level in post-treatment period had higher LRR, and relapsing patients had higher FBG levels in post-treatment period.

Diabetes Mellitus and Risk of Hepatocellular Carcinoma

The occurrence of hepatocellular carcinoma (HCC) is two to three times higher in patients with diabetes mellitus (DM), the prevalence of which is increasing sharply worldwide. The purpose of this review was to describe clinical links between DM and HCC and potential biological mechanisms that may account for this association. We evaluated the role of potential pathways that could account for the development of HCC with different etiologies in the presence of DM. In addition, we also briefly discuss the potential effect of other factors such as type and dosage of antidiabetic medicines and duration of DM on HCC risk.

Metformin use and survival outcomes in endometrial cancer: a systematic review and meta-analysis

Previous studies have evaluated the effects of metformin use on survival outcomes in endometrial cancer, but their results are inconsistent. We conducted a systematic review and meta-analysis to provide a quantitative assessment of the drug's effects based on available evidence. We searched PubMed, Embase, and the Cochrane Central Register of Controlled Trials to identify relevant studies that evaluated the association between metformin use on survival outcomes in endometrial cancer. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated to evaluate the association of metformin use with overall survival and with progression-free survival using a fixed-effects model. A total of nine studies involving 2,016 patients with endometrial cancer were identified. In a meta-analysis of eight studies involving 1,594 individuals, metformin use was associated with significant improvements in overall survival (HR, 0.51; 95% CI, 0.41 to 0.64). Metformin users similarly showed improved progression-free survival in a meta-analysis of two studies involving 632 individuals (HR, 0.63; 95% CI, 0.46 to 0.87). In conclusion, endometrial cancer patients who use metformin show improved overall survival and progression-free survival. Further studies are required to confirm the full potential effects of metformin use on survival outcomes in endometrial cancer.

Metformin: a review of its potential indications

Metformin is the most commonly prescribed drug for type 2 diabetes mellitus. In recent years, in addition to glucose lowering, several studies have presented evidence suggesting some potential role for metformin, such as antitumor effect, antiaging effect, cardiovascular protective effect, neuroprotective effect or an optional treatment for polycystic ovary syndrome. This paper will critically review the role of metformin to provide reference for doctors and researchers.

Lack of chemopreventive efficacy of metformin in rodent models of urinary bladder, head and neck, and colon/intestine cancer

Metformin is a biguanide employed in treating type II diabetes. Its potential efficacy for treating cancer has been demonstrated epidemiologically (lower cancer incidence in metformin users compared with users of sulfonylureas or insulin) and mechanistically, primarily in cell culture. Metformin decreases the levels of insulin-like growth factor 1 and secondarily inhibits the mammalian target of rapamycin pathway to exhibit anticancer effects. The current study examined its cancer preventive efficacy in multiple standard in situ arising cancer models. Metformin was administered orally by gavage or in the diet, at human equivalent doses, in numerous cancer models. In the hydroxybutyl(butyl)nitrosamine-induced model of invasive urinary bladder cancer, metformin (50 or 150 mg/kg body weight/day, intragastric) was ineffective despite high urinary concentrations of metformin. Metformin (250 or 500 ppm in diet) failed to decrease the incidence or invasiveness of squamous cell cancer of the tongue in a 4-nitroquinoline-1-(4NQO)-induced model. Finally, in the Min mouse model of gastrointestinal cancer, metformin (400 or 1,200 ppm in diet) was ineffective. Notably, a slight increase in intestinal tumor multiplicity was observed at the higher dose. Therefore, metformin lacked efficacy in multiple standard cancer models in non-diabetic rodents. This lack of efficacy may discourage any large phase clinical cancer trials in non-diabetic individuals in the absence of clear phase-II studies.

Prognostic significance of anti-diabetic medications in pancreatic cancer: A meta-analysis

The role of anti-diabetic medications in pancreatic cancer remains conflicting. We carried out a systematic search of Pubmed and Embase databases for studies published before August 2016, which assessed the associations between anti-diabetic medications (metformin, sulfonylureas, thiazolidinediones and insulin) intake and pancreatic cancer prognosis. Hazard ratios (HRs) with 95% confidence intervals (CIs) were estimated using the random-effects model. The primary outcomes of interest were overall survival (OS) and progression-free survival (PFS). Fourteen studies enrolling 94778 participants were eligible for inclusion, with 12 cohort studies and 2 randomized controlled trials (RCTs). Significant association between metformin (adjusted HR=0.77, 95% CI=0.68-0.87) use and OS was found in cohort studies, whereas no significant association between metformin use and PFS (HR=1.22; 95% CI=0.76-1.95) or OS (HR=1.20, 95% CI=0.84-1.72) in RCTs. No significant survival benefits were identified for insulin (HR=1.18, 95% CI=0.83-1.69), sulfonylureas (HR=1.03, 95% CI=0.81-1.30), or thiazolidinediones (HR=0.84, 95% CI=0.58-1.22). The trim-and-fill method and subgroup analyses stratified by the study characteristics confirmed the robustness of the results. Our findings provide strong evidence that metformin is associated with improved OS in pancreatic cancer patients in cohort studies. However, the effect of other anti-diabetic medications should be interpreted with caution owing to the limited number of studies.

Associations among Metabolism, Circadian Rhythm and Age-Associated Diseases

Accumulating epidemiological studies have implicated a strong link between age associated metabolic diseases and cancer, though direct and irrefutable evidence is missing. In this review, we discuss the connection between Warburg effects and tumorigenesis, as well as adaptive responses to environment such as circadian rhythms on molecular pathways involved in metabolism. We also review the central role of the sirtuin family of proteins in physiological modulation of cellular processes and age-associated metabolic diseases. We also provide a macroscopic view of how the circadian rhythm affects metabolism and may be involved in cell metabolism reprogramming and cancer pathogenesis. The aberrations in metabolism and the circadian system may lead to age-associated diseases directly or through intermediates. These intermediates may be either mutated or reprogrammed, thus becoming responsible for chromatin modification and oncogene transcription. Integration of circadian rhythm and metabolic reprogramming in the holistic understanding of metabolic diseases and cancer may provide additional insights into human diseases.