The double trouble of metabolic diseases: the diabetes-cancer link

Repurposing metabolic regulators: antidiabetic drugs as anticancer agents

Drug repurposing in cancer taps into the capabilities of existing drugs, initially designed for other ailments, as potential cancer treatments. It offers several advantages over traditional drug discovery, including reduced costs, reduced development timelines, and a lower risk of adverse effects. However, not all drug classes align seamlessly with a patient's condition or long-term usage. Hence, repurposing of chronically used drugs presents a more attractive option. On the other hand, metabolic reprogramming being an important hallmark of cancer paves the metabolic regulators as possible cancer therapeutics. This review emphasizes the importance and offers current insights into the repurposing of antidiabetic drugs, including metformin, sulfonylureas, sodium-glucose cotransporter 2 (SGLT2) inhibitors, dipeptidyl peptidase 4 (DPP-4) inhibitors, glucagon-like peptide-1 receptor agonists (GLP-1RAs), thiazolidinediones (TZD), and α-glucosidase inhibitors, against various types of cancers. Antidiabetic drugs, regulating metabolic pathways have gained considerable attention in cancer research. The literature reveals a complex relationship between antidiabetic drugs and cancer risk. Among the antidiabetic drugs, metformin may possess anti-cancer properties, potentially reducing cancer cell proliferation, inducing apoptosis, and enhancing cancer cell sensitivity to chemotherapy. However, other antidiabetic drugs have revealed heterogeneous responses. Sulfonylureas and TZDs have not demonstrated consistent anti-cancer activity, while SGLT2 inhibitors and DPP-4 inhibitors have shown some potential benefits. GLP-1RAs have raised concerns due to possible associations with an increased risk of certain cancers. This review highlights that further research is warranted to elucidate the mechanisms underlying the potential anti-cancer effects of these drugs and to establish their efficacy and safety in clinical settings.

Assessment of Pre-existing Type 2 Diabetes Mellitus Prevalence and Risk Factors Among Colorectal Cancer Patients in King Abdulaziz Medical City, Jeddah

BACKGROUND

Diabetes mellitus (DM) and cancer are recognized as non-communicable chronic disorders which are among the top ten causes of death globally. In Saudi Arabia, the prevalence of type 2 DM (T2DM) and colorectal cancer (CRC) is alarmingly high. Both T2DM and CRC share common risk factors. In this study, we aim to assess the prevalence of pre-existing T2DM among CRC Saudi patients.

METHODS

In this cross-sectional study, data were collected from the medical records of 275 Saudi adult patients with CRC from 2009 to 2018 at King Abdulaziz Medical City, Jeddah (KAMC-J).

RESULTS

Participants had a mean age of 57.0 years, standard deviation (SD) of 13.0, and were mostly males (60.00%) and Saudi (100.0%). Participants had a mean BMI of 26.42 (7.35) kg/m². The prevalence of pre-existing T2DM in this study was 40.80%. 15.8% of participants were overweight and obese (BMI>30), respectively. The average age of diabetics and non-diabetics was 63.6 (10.64) and 52.73 (12.43), respectively. Diabetic patients are significantly older than non-diabetic patients (p<0.001). The average BMI for diabetics was 26.96 (7.26) kg/m², whereas the average BMI for non-diabetics was 25.93 (7.48) kg/m². No significant differences were found between the two groups.

CONCLUSION

This study provides new insight into the high prevalence of pre-existing T2DM in CRC patients in Saudi Arabia. In particular, the age of diagnosis of CRC in diabetic patients was significantly higher than in non-diabetics.

Association Between Diabetes and the Risk of Kidney Cancer: Systematic Review and Meta-Analysis

Diabetes is a risk factor for several types of cancer, but the specific relationship between diabetes and kidney cancer is not well understood. We conducted a search strategy in scientific databases for case-control and cohort studies on this topic. We analyzed 17 studies and found that diabetes was significantly associated with the risk of developing kidney cancer and that this risk was slightly stronger for women and for people living in Asia. These findings were not influenced by obesity, cigarette smoking, or hypertension. We conclude that diabetes is an independent risk factor for the development of kidney cancer.

PPAR-Responsive Elements Enriched with Alu Repeats May Contribute to Distinctive PPARγ-DNMT1 Interactions in the Genome

Simple Summary

This study aimed to explore the potential role of PPARγ–DNMT1 interaction through PPAR-responsive elements (PPREs), which we have found to be enriched with Alu repeats. Apart from protein–protein interactions and co-expression in multiple cancer types, we exclusively described a prognostic role for PPARγ in uveal melanoma (UM).

Abstract

Background: PPARγ (peroxisome proliferator-activated receptor gamma) is involved in the pathology of numerous diseases, including UM and other types of cancer. Emerging evidence suggests that an interaction between PPARγ and DNMTs (DNA methyltransferase) plays a role in cancer that is yet to be defined. Methods: The configuration of the repeating elements was performed with CAP3 and MAFFT, and the structural modelling was conducted with HDOCK. An evolutionary action scores algorithm was used to identify oncogenic variants. A systematic bioinformatic appraisal of PPARγ and DNMT1 was performed across 29 tumor types and UM available in The Cancer Genome Atlas (TCGA). Results: PPAR-responsive elements (PPREs) enriched with Alu repeats are associated with different genomic regions, particularly the promotor region of DNMT1. PPARγ–DNMT1 co-expression is significantly associated with several cancers. C-terminals of PPARγ and DNMT1 appear to be the potential protein–protein interaction sites where disease-specific mutations may directly impair the respective protein functions. Furthermore, PPARγ expression could be identified as an additional prognostic marker for UM. Conclusions: We hypothesize that the function of PPARγ requires an additional contribution of Alu repeats which may directly influence the DNMT1 network. Regarding UM, PPARγ appears to be an additional discriminatory prognostic marker, in particular in disomy 3 tumors.

Regulatory MicroRNAs in T2DM and Breast Cancer

MicroRNAs orchestrate the tight regulation of numerous cellular processes and the deregulation in their activities has been implicated in many diseases, including diabetes and cancer. There is an increasing amount of epidemiological evidence associating diabetes, particularly type 2 diabetes mellitus, to an elevated risk of various cancer types, including breast cancer. However, little is yet known about the underlying molecular mechanisms and even less about the role miRNAs play in driving the tumorigenic potential of the cell signaling underlying diabetes pathogenesis. This article reviews the role of miRNA in bridging the diabetes–breast cancer association by discussing specific miRNAs that are implicated in diabetes and breast cancer and highlighting the overlap between the disease-specific regulatory miRNA networks to identify a 20-miRNA signature that is common to both diseases. Potential therapeutic targeting of these molecular players may help to alleviate the socioeconomic burden on public health that is imposed by the type 2 diabetes mellitus (T2DM)–breast cancer association.

Fucoidan Structure and Its Impact on Glucose Metabolism: Implications for Diabetes and Cancer Therapy

Fucoidans are complex polysaccharides derived from brown seaweeds which consist of considerable proportions of L-fucose and other monosaccharides, and sulphated ester residues. The search for novel and natural bioproduct drugs (due to toxicity issues associated with chemotherapeutics) has led to the extensive study of fucoidan due to reports of it having several bioactive characteristics. Among other fucoidan bioactivities, antidiabetic and anticancer properties have received the most research attention in the past decade. However, the elucidation of the fucoidan structure and its biological activity is still vague. In addition, research has suggested that there is a link between diabetes and cancer; however, limited data exist where dual chemotherapeutic efforts are elucidated. This review provides an overview of glucose metabolism, which is the central process involved in the progression of both diseases. We also highlight potential therapeutic targets and show the relevance of fucoidan and its derivatives as a candidate for both cancer and diabetes therapy.

Cross Talk between COVID-19 and Breast Cancer

Cancer patients are more susceptible to COVID-19; however, the prevalence of COVID-19 in different types of cancer is still inconsistent and inconclusive. Here, we delineate the intricate relationship between breast cancer and COVID-19. Breast cancer and COVID-19 share the involvement of common comorbidities, hormonal signalling pathways, gender differences, rennin- angiotensin system (RAS), angiotensin-converting enzyme-2 (ACE-2), transmembrane protease serine 2 (TMPRSS2) and dipeptidyl peptidase-IV (DPP-IV). We also shed light on the possible effects of therapeutic modalities of COVID-19 on breast cancer outcomes. Briefly, we conclude that breast cancer patients are more susceptible to COVID-19 in comparison with their normal counterparts. Women are more resistant to the occurrence and severity of COVID-19. Increased expressions of ACE2 and TMPRSS2 are correlated with occurrence and severity of COVID-19, but higher expression of ACE2 and lower expression of TMPRSS2 are prognostic markers for overall disease free survival in breast cancer. The ACE2 inhibitors and ibuprofen therapies for COVID-19 treatment may aggravate the clinical condition of breast cancer patients through chemo-resistance and metastasis. Most of the available therapeutic modalities for COVID-19 were also found to exert positive effects on breast cancer outcomes. Besides drugs in clinical trend, TMPRSS2 inhibitors, estrogen supplementation, androgen deprivation and DPP-IV inhibitors may also be used to treat breast cancer patients infected with SARS-CoV-2. However, drug-drug interactions suggest that some of the drugs used for the treatment of COVID-19 may modulate the drug metabolism of anticancer therapies which may lead to adverse drug reaction events.

Management of metabolic adverse events of targeted therapies and immune checkpoint inhibitors in cancer patients: an Associazione Italiana Oncologia Medica (AIOM)/Associazione Medici Diabetologi (AMD)/Società Italiana Farmacologia (SIF) multidisciplinary consensus position paper

The growing insights in the next-generation immunotherapy and the state-of-the-art advancement in targeted-agents significantly improved clinical outcome of cancer patients by pointing towards a unexplored Achilles' heel. Novel toxicity profiles have been uncovered, representing unmet medical needs. Thus, a panel of expert provide comprehensive pharmacological and clinical evidence, to provide a patient-tailored approach to metabolic adverse events associated with novel anti-cancer treatments. Prompted by the need of a multidisciplinary cooperation, a working group of Associazione Italiana Oncologia Medica (AIOM), Associazione Medici Diabetologi (AMD) and Società Italiana Farmacologia (SIF) examined the available literature data. The identification of patient risk profile and the characterization of metabolic effects of novel anti-tumour drugs is clearly a clinical challenge that can be addressed by a multidisciplinary clinical approach. Therefore, this review pinpoints the relevance of the challenging profiling of the patient suffering from dysmetabolic conditions induced by the novel therapeutics in medical oncology.

Influence and mechanism of miR-99a suppressing development of colorectal cancer (CRC) with diabetes mellitus (DM)

OBJECTIVE

This study aimed to identify the changes of miRNAs in colorectal cancer (CRC) complicated with diabetes mellitus (DM) (CRC + DM) tissues and their potential effects.

METHODS

The changes of miRNAs in CRC + DM tissues were determined by miRNA microarray. The expression levels of miR-99a in 40 clinical specimens and 6 CRC cell lines were determined by qRT-PCR. The capacity for miR-99a to induce cell proliferation and invasion was examined with miR-99a-overexpressing HCT-116 cells. The relative mTOR mRNA and protein levels were determined by qRT-PCR and Western blotting, respectively, in HCT-116 cells transfected with miR-99a. The dual luciferase assay was performed to confirm the direct regulation of miR-99a on mTOR 3'-UTR. The HCT-116 cells were treated with 100 mg/L advanced glycation end products (AGEs); then, the mTOR expression levels were determined by qRT-PCR, Western blotting, and immunohistochemistry.

RESULTS

Seventeen miRNAs were found to be differentially expressed among normal tissue, CRC tissue, and CRC with DM tissue, including 15 upregulated and 2 downregulated with fold changs of more than 2 times. qRT-PCR confirmed that miR-99a was downregulated in CRC and CRC + DM tissues. In addition, miR-99a overexpression remarkably impaired CRC cell proliferation and metastasis, and negatively regulated mTOR signaling through direct binding to the 3'-UTR of mTOR. AGEs could suppress miR-99a and stimulate mTOR signaling in CRC cells. Increased mTOR was also identified in CRC with DM tissues.

CONCLUSION

Our findings indicate that miR-99a is a potential marker and therapeutic target of CRC complicated with DM, and that AGEs impair miR-99a-overactivated mTOR signaling in CRC with DM patients, which promotes CRC development.

Diabetes, Obesity, and the Metabolic Syndrome as Prognostic Factors in Stages I to III Colorectal Cancer Patients

BACKGROUND

Attempts to introduce prognostic factors for survival outcomes in localized colorectal cancer patients receiving surgical treatment with or without adjuvant therapies, beyond the classic staging parameters, have been met with limited success. Obesity and diabetes mellitus are among the conditions that predispose to colorectal cancer but their value as prognostic markers once the disease is diagnosed is controversial.

PATIENTS AND METHODS

This study examines the prognostic value of the components of metabolic syndrome in a retrospective series of colorectal cancer patients with stages I to III disease followed in a single center.

RESULTS

Among the four components of the metabolic syndrome, only diabetes was independently associated with progression-free survival (PFS) while obesity, hypertension, and dyslipidemia were not. No associations of the metabolic syndrome (MS) or its components with overall survival (OS) were observed in multivariate analysis.

CONCLUSION

These data pinpoint to diabetes mellitus (DM) as a possible prognostic factor for PFS in localized colorectal cancer and further cast doubt for the value of obesity as measured by body mass index (BMI) on local stage colorectal cancer prognosis.

The metabolic syndrome and its components as prognostic factors in metastatic colorectal cancer

BACKGROUND

Components of the metabolic syndrome (MetS) are involved in colorectal cancer development and the incidence of the disease is higher in obese and diabetic patients. Nevertheless, the value of these diseases or the MetS as a whole as prognostic markers once colorectal cancer is diagnosed is controversial.

METHODS

Patients with metastatic colorectal cancer treated in our center over a 6-year period were reviewed and data on baseline characteristics of the patients and their cancers were extracted. Data on the presence and pharmacologic treatments of the four components of the MetS (obesity, diabetes, hypertension, and dyslipidemia) were also recorded. Overall survival (OS) and progression-free survival (PFS), Kaplan-Meier curves of the various groups were constructed and compared with the log-rank test.

RESULTS

One hundred and twenty-three patients were included in the analysis. The prevalence of the four MetS components was 66.1% for overweight/obesity, 25.2% for diabetes, 61% for hypertension, and 41.5% for dyslipidemia. Among the four components of the metabolic syndrome, none was associated with either PFS or OS. Diabetes tended to approach significance for PFS (p = 0.08). The MetS as a whole did not influence survival outcome. MetS was not prognostic even if the overweight category was not considered as a positive element of the syndrome.

CONCLUSION

These data suggest that diabetes or other metabolic syndrome elements are not prognostic factors for PFS or OS in metastatic colorectal cancer. Further investigation may be warranted with a focus on refinement of the metabolic evaluation.

The Role of RNA Editing in Cancer Development and Metabolic Disorders

Numerous human diseases arise from alterations of genetic information, most notably DNA mutations. Thought to be merely the intermediate between DNA and protein, changes in RNA sequence were an afterthought until the discovery of RNA editing 30 years ago. RNA editing alters RNA sequence without altering the sequence or integrity of genomic DNA. The most common RNA editing events are A-to-I changes mediated by adenosine deaminase acting on RNA (ADAR), and C-to-U editing mediated by apolipoprotein B mRNA editing enzyme, catalytic polypeptide 1 (APOBEC1). Both A-to-I and C-to-U editing were first identified in the context of embryonic development and physiological homeostasis. The role of RNA editing in human disease has only recently started to be understood. In this review, the impact of RNA editing on the development of cancer and metabolic disorders will be examined. Distinctive functions of each RNA editase that regulate either A-to-I or C-to-U editing will be highlighted in addition to pointing out important regulatory mechanisms governing these processes. The potential of developing novel therapeutic approaches through intervention of RNA editing will be explored. As the role of RNA editing in human disease is elucidated, the clinical utility of RNA editing targeted therapies will be needed. This review aims to serve as a bridge of information between past findings and future directions of RNA editing in the context of cancer and metabolic disease.

Cancer incidence among Finnish people with type 2 diabetes during 1989-2014

Diabetes and cancer are common diseases both with enormous impact on health burden globally. The increased risk of several types of cancer among people with type 2 diabetes mellitus has been indicated repeatedly. This study aimed at exploring and describing the association between type 2 diabetes and cancer incidence. A cohort of 428,326 people with type 2 diabetes was identified from the Finnish National Diabetes Register and followed up through a register linkage with the Finnish Cancer Registry for cancer incidence during 1988-2014. A total of 74,063 cases of cancer occurred in this cohort in 4.48 million person-years. This accounted for 16% more than the expected cancer incidence in the Finnish general population; the standardized incidence ratio (SIR) was 1.16 (95% confidence interval [CI] 1.15-1.16). There was a statistically significant excess of cancers of lip (SIR = 1.40, CI = 1.28-1.53), liver (SIR = 2.44, CI = 2.35-2.53), pancreas (SIR = 1.75, CI = 1.70-1.79), stomach (SIR = 1.22, CI = 1.18-1.26), colon (SIR = 1.22, CI = 1.19-1.25), gallbladder and bile ducts (SIR = 1.29, CI = 1.21-1.36), non-melanoma skin (SIR = 1.18, CI = 1.15-1.22), kidney (SIR = 1.42, CI = 1.37-1.47), bladder (SIR = 1.17, CI = 1.13-1.21), and thyroid (SIR = 1.22, CI = 1.12-1.31). There was a small statistically significant decrease in prostate cancer incidence (SIR = 0.95, CI = 0.93-0.96). This study showed an association between type 2 diabetes mellitus and the incidence of cancer at numerous sites in the Finnish population.

Challenges and perspectives in the treatment of diabetes associated breast cancer

Type 2 diabetes mellitus is one of the most common chronic disease worldwide and affects all cross-sections of the society including children, women, youth and adults. Scientific evidence has linked diabetes to higher incidence, accelerated progression and increased aggressiveness of different cancers. Among the different forms of cancer, research has reinforced a link between diabetes and the risk of breast cancer. Some studies have specifically linked diabetes to the highly aggressive, triple negative breast cancers (TNBCs) which do not respond to conventional hormonal/HER2 targeted interventions, have chances of early recurrence, metastasize, tend to be more invasive in nature and develop drug resistance. Commonly used anti-diabetic drugs, such as metformin, have recently gained importance in the treatment of breast cancer due to their proposed anti-cancer properties. Here we discuss the link between diabetes and breast cancer, the metabolic disturbances in diabetes that support the development of breast cancer, the challenges involved and future perspective and directions. We link the three main metabolic disturbances (dyslipidemia, hyperinsulinemia and hyperglycemia) that occur in diabetes to potential aberrant molecular pathways that may lead to the development of an oncogenic phenotype of the breast tissue, thereby leading to acceleration of cell growth, proliferation, migration, inflammation, angiogenesis, EMT and metastasis and inhibition of apoptosis in breast cancer cells. Furthermore, managing diabetes and treating cancer using a combination of anti-diabetic and classical anti-cancer drugs should prove to be more efficient in the treatment diabetes associated cancers.

Glucose-regulated and drug-perturbed phosphoproteome reveals molecular mechanisms controlling insulin secretion

Insulin-secreting beta cells play an essential role in maintaining physiological blood glucose levels, and their dysfunction leads to the development of diabetes. To elucidate the signalling events regulating insulin secretion, we applied a recently developed phosphoproteomics workflow. We quantified the time-resolved phosphoproteome of murine pancreatic cells following their exposure to glucose and in combination with small molecule compounds that promote insulin secretion. The quantitative phosphoproteome of 30,000 sites clustered into three main groups in concordance with the modulation of the three key kinases: PKA, PKC and CK2A. A high-resolution time course revealed key novel regulatory sites, revealing the importance of methyltransferase DNMT3A phosphorylation in the glucose response. Remarkably a significant proportion of these novel regulatory sites is significantly downregulated in diabetic islets. Control of insulin secretion is embedded in an unexpectedly broad and complex range of cellular functions, which are perturbed by drugs in multiple ways.

Dysfunction in insulin secretion is a main driver of type 2 diabetes development. Here the authors monitor phosphoproteome modulation in cells stimulated with glucose and treated with drugs affecting glucose-mediated insulin secretion to reveal phosphorylation sites implicated in insulin secretion control and gene expression regulation.