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Highlights • Colorectal carcinoma associated with proficient MLH1 gene are more aggressive cancers. • MLH1 influences the chemoresistance by mediating nuclear autophagy, nucleophagy. • Interaction among MLH1 and autophagy marker LC3 facilitated nucleophagy induction. • MLH1 mediated nucleophagy determined chemoresistance in colorectal cancer cells., Graphical abstract Image, graphical abstract, Colorectal Cancer (CRC) with Microsatellite instability (MSI) and mutLhomolog-1 (MLH1) gene deficiency are less aggressive than MLH1 proficient cancers. MLH1 is involved in several cellular processes, but its connection with the autophagy-dependent cellular response towards anticancer drugs remains unclear. In this study, we aimed to investigate the interaction between MLH1 and the autophagy marker LC3, which facilitated nucleophagy induction, and its potential role in determining sensitivity to 5-Fluorouracil (5-FU) induced cell death. To examine the role of MLH1 in DNA-damage-induced nucleophagy in CRC cells, we utilized a panel of MLH1 deficient and MLH1 proficient CRC cell lines. We included a parental HCT116 cell line (MLH1−/−) and its isogenic cell line HCT116 MLH1+/− in which a single allele of the MLH1 gene was introduced using CRISPR-Cas9 gene editing. We observed that MLH1 proficient cells were less sensitive to the 5-FU-induced cytotoxic effect. The 5-FU induced DNA damage led to LC3 up-regulation, which was dependent on MLH1 overexpression. Moreover, immunofluorescence and immunoprecipitation data showed LC3 and MLH1 were colocalized in CRC cells. Consequently, MLH1 dependent 5-FU-induced DNA damage contributed to the formation of micronuclei. These micronuclei colocalize with autolysosome, indicating a cytoprotective role of MLH1 dependent nucleophagy. Interestingly, siRNA knockdown of MLH1 in HCT116 MLH1+/− prevented LC3 upregulation and micronuclei formation. These novel data are the first to show an essential role of MLH1 in mediating the chemoresistance and survival of cancer cells by increasing the LC3 expression and inducing nucleophagy in 5-FU treated CRC cells.

Background Fat mass and obesity-associated protein gene variants have shown diverse influence on body weight and metabolism across different populations. Overweight, obesity and metabolic syndrome are multifactorial major health problems in the UAE and worldwide. Insulin resistance represents the link between overweight and development of metabolic syndrome and type 2 diabetes mellitus. We investigated two (FTO) variants in Emirati population, in relation to insulin resistance and different parameters of metabolic syndrome. Methods We recruited 259 Emiratis through the UAE National Diabetes and Lifestyle Project. Ethical approval was obtained. Besides basic data collection, venous blood samples were collected. Fasting blood glucose, Lipid profile, and insulin levels were measured. Genotyping for (FTO) rs9939609 (A>T) and rs9930506 (G>A) were performed using real time-PCR. Insulin resistance were identified using HOMA2-IR calculation; with a cut-off point of 1.4 for female and 1.18 for male subjects. Results The study included 259 Emiratis (age range 30–53 years, mean 41.76 years, 54.4% females), 24.5% are diabetic and 30.8% are hypertensive, with body mass index of 28.4 ± 5.9 and 28.7 ± 5.7 kg/m2 in female and male subjects, respectively. Homozygous A of rs9939609 showed significantly higher fasting glucose compared to other genotypes (p = 0.04) with a trend of higher insulin level and HOMA-2IR. The A/A diabetic patients (n = 13) showed significantly higher insulin levels compared to other genotypes. G allele of rs9930506 showed a trend of higher fasting glucose and HOMA-2IR, but lower insulin level and HbA1c. No association of genotypes was detected with other components of metabolic syndrome. Conclusion There is an association of FTO rs9939609 A/A genotype and impaired fasting glucose and insulin resistance. Homozygous A genotype diabetic patients may be more vulnerable to blood glucose fluctuation. Focused genotyping can help the health care providers to identify high risk groups of both normal population and diabetic patients to intervene accordingly.

Background Statin-induced myopathy has been linked to the C allele of a single nucleotide polymorphism (SNP) (rs4149056) of SLCO1B1 gene. This effect is more significant, but not restricted to simvastatin. Many studies have included European, American, African and Southeast Asian ancestries, but few were carried out on Middle Eastern population. Aim To detect the prevalence of SLCO1B1 rs4149056 (521T > C) in Emirati population. Method We recruited 282 Emiratis through the UAE National Diabetes and Lifestyle Project. Ethical approval was obtained before the study starts. Besides basic data collection, venous blood samples were collected. Fasting blood glucose, Lipid profile, and insulin levels were measured. Genotyping for rs4149056 (521T > C) was tested in triplicates through Real Time-PCR using TaqMan® Drug Metabolism Genotyping Assay. rs2306283 (388A > G) was analyzed for comparison. In addition, presence of minor alleles of both SNPs define stronger association with statin-induced myopathy. Results The study included 282 individuals, 52.8% were males with median age of 39.5 years. 10% had Diabetes Mellitus and 23% were hypertensive. Median of body mass index (BMI) was 27.68 kg/m2 in males and 28.38 kg/m2 in females. One-hundred ninety-seven (69.9%) showed abnormal lipid profile (either increased LDL-cholesterol or triglycerides or both). For rs4149056, C allele was present in 21.3% (2.8% homozygous C and 18.4% heterozygous CT). Although homozygous C genotype prevalence was low, compared with Caucasians (4%) and Africans (0%), C allele was associated with a trend of having higher BMI and abnormal lipid profile. C allele subjects were all pre-diabetics with mean glycated hemoglobin above 6%. Mean BMI in CC, CT, and TT genotypes was 30.91 ± 4.4, 29.48 ± 4.2, 27.96 ± 5.5 kg/m2 respectively, with lack of such a trend observed with the different genotypes of the rs2306283 (used for comparison). Abnormal lipid profile was observed in 7/8(87.5%), 38/52(73.1%) and 152/222(70%) of the CC, CT, and TT genotypes respectively. Conclusion There is lower prevalence of statin-induced myopathy-linked C allele of rs4149056 in SLCO1B1 gene in Emirati population, compared to Caucasians and Africans. However, there is a trend of higher glycosylated hemoglobin and BMI associated with normal lipid profile in patients having this allele.

Introduction Incretin-based therapy (like GLP-1R agonists) have been recently widely used as for treatment of diabetes and obesity. They have favourable effect on proliferation of beta cells of pancreas. GLP-1 mediates an incretin effect, by which oral glucose has a greater stimulatory effect on insulin secretion than intravenous glucose. GLP-1 binds to a specific GLP-1 receptor (GLP-1R), which is expressed in many tissues including; pancreatic beta cells, gastric mucosa, kidney, lung, heart, skin, immune cells, and the hypothalamus. In addition, those receptors are expressed in some types of cancers; including medullary thyroid, ovarian and colorectal cancers. The aim of our study is to explore the effect of GLP-1R agonist (exendin-4) and GLP-1 antagonist (exendin 9–39) on human pheochromocytoma (hPheo1) and colorectal cancer (HT29) cell proliferation and migration. Material and methods GLP-1 receptor expression was detected by Western Blotting and real time PCR in 4 different cell lines; colorectal HT29, HCT116, [m1] pheochromocutoma (hPheo1) and neuroblastoma (SH-SY-5Y). Different concentrations (0.1–100 µM) of exendin-4 and exendin 9–39 (5 and 10 µM) were applied on hPheo1 and HT29 cell lines. The effect on proliferation was detected after 48 and 72 hours by cell viability assay (MTT). Cell migration assay was detected by wound healing experiment through measuring migration distance rate. Statistical significance was assessed using ANOVA, followed by post hoc Tukey Kramer test when groups were significantly different. Results and discussions The GLP1R gene is expressed in all 4 cell lines cell lines. Exendin-4 increased proliferation of hPheo and HT29 cell lines at 0.1μM and 1μM concentrations, as compared to control group (p Conclusion The GLP-1R agonists may increase the proliferation of cancer cells initially and at low doses, whereas higher doses decreases the proliferation rate. They are likely to have no effect, or potentially favourable suppressing effect on cancer cell proliferation and migration in pheochromocytoma and colorectal cancer.

Introduction Protein arginine methyltransferase 5 (PRMT5) is an enzyme that is greatly implicated in diverse cellular processes, including transcriptional regulation, RNA metabolism, and cell-cycle regulation. It was found in previous studies to be highly expressed in cancers including lung adenocarcinoma, Hepatocellular Carcinoma (HCC), and melanoma; in amounts much more significant as compared to benign tissues; raising evidence that PRMT5 is involved in tumorigenesis. Recent studies have proven that inhibition of PRMT5 in HCC cells through the use of AMI-1, a water soluble selective protein arginine methyltransferase inhibitor significantly reduces the proliferation and migration of HCC cells. It was also found that β-catenin is a target of PRMT5, therefore inhibiting PRMT5 resulted in the silencing of β-catenin; as well as its downstream cell-cycle regulator cyclin D1. The aim of our study is to investigate the effect of PRMT5 inhibitor (AMI-1) on the proliferation, migration and survival of lung adenocarcinoma cells. Material and methods We compared the effect of AMI-1 on lung adenocarcinoma (A549 cell line) suppression with the standard chemotherapeutic agent, cisplatin, by measuring cell viability using MTT assay, PMRT5/β-catenin expression via Western Blotting, the extent of cell migration through wound healing assay, and survival of cancer cells by performing cell cycle progression and Annexin-V staining assays. Results and discussions Treating the cells with a combination of 10 µM AMI-1 and IC50 of Cisplatin (23.4 µM) significantly decreased cell viability at 24 and 48 hours. Moreover, treatment with both drugs at 48 hours led to a reduction in cell migration measured by the migration rate. AMI-1 induced G2/M arrest in A549 cells at 24 hours. This effect was enhanced in the combined treatment. Furthermore, A549 cells were unable to recycle again as they arrested at G1 after 48 hours of combination treatment. There was a minor cell death induction after 48 hours of treatment with both drugs. Neither PRTM5 nor β-catenin protein levels were affected due to the treatment. However, 48 hours treatment with AMI-1 alone or in combination with Cisplatin reduced the methylation of PRTM5- downstream target, Histone 4. Conclusion Inhibition of the intracellular enzyme protein arginine methyltransferase 5 by AMI-1 potentiates the anti-cancer effect to cisplatin in the lung adenocarcinoma, with a promising potential role as an adjuvant therapy in lung cancer. The?effect is likely mediated by methylation reduction of histone-4.