Whole exome sequencing identifies MAP3K1, MSH2, and MLH1 as potential cancer-predisposing genes in familial early-onset colorectal cancer.

The incidence of early-onset colorectal cancer (CRC), which affects people under 50, is increasing for unknown reasons. Additionally, no underlying genetic cause is found in 20%-30% of patients suspected of having familial CRC syndrome. Whole exome sequencing (WES) has generated evidence for new genes associated with CRC susceptibility, but many patients remain undiagnosed. This study applied WES in five early-onset CRC patients from three unrelated families to identify novel genetic variants that could be linked to rapid disease development. Furthermore, the candidate variants were validated using Sanger sequencing. Two heterozygote variations, c.1077-2A>G and c.199G>A, were found in the MSH2 and the MLH1 genes, respectively. Sanger sequencing analysis confirmed that these (likely) pathogenic mutations segregated in all the affected families' members. In addition, we identified a rare heterozygote variant (c.175C>T) with suspected pathogenic potential in the MAP3K1 gene; formally the variant is of uncertain significance (VUS). Our findings support the hypothesis that CRC onset may be oligogenic and molecularly heterogeneous. Larger and more robust studies are needed to understand the genetic basis of early-onset CRC development, combined with novel functional analyses and omics approaches.

DNA methylation biomarkers in colorectal cancer: Clinical applications for precision medicine.

Colorectal cancer (CRC) is the second leading cause of cancer death worldwide that is attributed to gradual long-term accumulation of both genetic and epigenetic changes. To reduce the mortality rate of CRC and to improve treatment efficacy, it will be important to develop accurate noninvasive diagnostic tests for screening, acute and personalized diagnosis. Epigenetic changes such as DNA methylation play an important role in the development and progression of CRC. Over the last decade, a panel of DNA methylation markers has been reported showing a high accuracy and reproducibility in various semi-invasive or noninvasive biosamples. Research to obtain comprehensive panels of markers allowing a highly sensitive and differentiating diagnosis of CRC is ongoing. Moreover, the epigenetic alterations for cancer therapy, as a precision medicine strategy will increase their therapeutic potential over time. Here, we discuss the current state of DNA methylation-based biomarkers and their impact on CRC diagnosis. We emphasize the need to further identify and stratify methylation-biomarkers and to develop robust and effective detection methods that are applicable for a routine clinical setting of CRC diagnostics particularly at the early stage of the disease.

Evaluation of miR-200c-3p and miR-421-5p levels during immune responses in the admitted and recovered COVID-19 subjects.

Angiotensin-converting enzyme 2 (ACE2) acts as a key receptor for the spike of SARS-CoV-2. Two main microRNAs (miRs), miR-200c-3p and miR-421-5p, are considered to modulate the expression of ACE2 gene and alterations in the expression of these miRNAs may influence the outcomes of COVID-19 infection. Accordingly, we examined whether miRNAs directing ACE2 expression altered in the SARS-CoV-2 infection. 30 patients with COVID-19 included in the study. At the time of admission and discharge, the expression of miR-200c-3p and miR-421-5p, inflammatory cytokine IL-6, and regulatory T cells' expression profiles (CD4, CD25, and Foxp3) were examined using quantitative real-time PCR method. At the time of admission, the expression levels of miR-200c-3p and miR-421-5p as well as CD4, CD25, and Foxp3 significantly decreased while IL-6 expression notably enhanced. However, by the time of discharge, the expression levels of the genes were opposite to the time of admission. Moreover, Pearson correlation analysis indicated that IL-6 expression negatively correlated with Foxp3 and miR-200c-3p expressions despite miR-421-5p and miR-200c-3p positively correlated at admission time. By manipulating miR-200c-3p and miR-421-5p expressions and controlling the ACE2 level, it is plausible to modulate the inflammation by reducing IL-6 and maintenance tolerance hemostasis during COVID-19 infection.

Investigating the Relationship Between the Expression Level of Mucin Gene Cluster (MUC2, MUC5A, and MUC5B) and Clinicopathological Characterization of Colorectal Cancer.

Background: Colorectal cancer (CRC) is one of the most common cancers in the world and has a high mortality rate. It is accepted that dysfunction in the expression of mucins are associated with the occurrence and development of CRC. Therefore, the present study aimed to investigate the expression of MUC2, MUC5A, and MUC5B genes in CRC and their relationship with clinicopathological variables. Materials and Methods: The population included 28 patients after a colonoscopy and confirmation of the results. Tumors and parallel adjacent normal tissues from CRC patients were collected. RNA extraction and cDNA synthesis were performed using the corresponding kits. The gene primer was designed and RT-PCR was used to evaluate gene expression. The t-test and ANOVA were used to examine the differences between the different groups. Data analysis was performed using Prism8 software. Tumors from CRC patients were retrospectively collected from Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Results: The results showed that the expression of MUC2, MUC5A, and MUC5B genes was lower in patients with CRC aged 50 years or younger than was in older patients (P<0.05). Only the MUC5B gene expression was associated with tumor grades, which was higher in poorly differentiated tumors. The expression of MUC5A and MUC2 genes was higher in stage IV of the tumor than in other stages (P<0.05). Conclusion: Among the changes in the expression of MUC secretory genes, including MUC2, MUC5A, and MUC5B and clinicopathological variables, there was a relationship that could have prognostic and diagnostic value in CRC. Conclusion: None.

Expression of Main Toll-Like Receptors in Patients with Different Types of Colorectal Polyps and Their Relationship with Gut Microbiota.

Abnormal activation of Toll-like receptor (TLRs) signaling can result in colon cancer development. The aim of this study was to investigate the expression of important TLRs in different histological types of colorectal polyps and evaluate their relationship with intestinal microbiota. The expression levels of TLR2, 3, 4, and 5 were analyzed in intestinal biopsy specimens of 21 hyperplastic polyp (HP), 16 sessile serrated adenoma (SSA), 29 tubular adenoma (TA), 21 villous/tubulovillous (VP/TVP) cases, and 31 normal controls. In addition, selected gut bacteria including Streptococcus bovis, Enterococcus faecalis, Enterotoxigenic Bacteroides fragilis (ETBF), Fusobacterium nucleatum, Porphyromonas spp., Lactobacillus spp., Roseburia spp., and Bifidobacterium spp. were quantified in fecal samples using absolute qRT PCR, and, finally, the association between TLRs and these gut microbiota- was evaluated by Spearman's correlation coefficient. Higher expression of TLR2 and TLR4 in VP/TVP and TA, and lower expression levels of TLR3 and TLR5 in all type of polyps were observed. The differences in TLR expression patterns was not only dependent on the histology, location, size, and dysplasia grade of polyps but also related to the intestinal microbiota patterns. TLR2 and TLR4 expression was directly associated with the F. nucleatum, E. faecalis, S. bovis, Porphyromonas, and inversely to Bifidobacterium, Lactobacillus, and Roseburia quantity. Furthermore, TLR3 and TLR5 expression was directly associated with Bifidobacterium, Roseburia, and Lactobacillus quantity. Our results suggest a possible critical role of TLRs during colorectal polyp progression. An abnormal regulation of TLRs in relation to gut microbial quantity may contribute to carcinogenesis.

Investigating the diagnostic performance of HOTTIP, PVT1, and UCA1 long noncoding RNAs as a predictive panel for the screening of colorectal cancer patients with lymph node metastasis.

Like other noncoding RNAs (ncRNAs), dysregulation of long ncRNAs (lncRNAs) has been associated with various clinicopathological features of colorectal cancer (CRC) patients such as lymph node metastasis (LNM). Recently, three aberrant expressed oncogenic lncRNA (onco-lncRNAs), including HOXA transcript at the distal tip (HOTTIP), plasmacytoma variant translocation 1 (PVT1), and urothelial carcinoma associated 1 (UCA1) have been reported in LNM. Herein, we compared the diagnostic performance of these lncRNAs as individual biomarkers and as a discriminating panel between LNM CRC patients, nonmetastatic lymph nodes (NLN) and normal healthy subjects. The lncRNAs expression level was measured by quantitative real-time PCR and analyzed by the Mann-Whitney U test. The receiver operating characteristic (ROC) curve analysis was applied to evaluate the diagnostic power. The Kaplan-Meier survival analysis was performed to outline the overall survival (OS) of CRC patients with an abnormal level of lncRNAs. The area under the ROC curve (AUC) of the overexpressed HOTTIP (0.7817; 95% CI, 0.6809-0.8824), PVT1 (0.8559; 95% CI, 0.7737-0.9382), and UCA1 (0.8135; 95% CI, 0.722-0.9051) introduced them as individual CRC biomarkers. As a predictive panel, the AUC values of the HOTTIP, PVT1, and UCA1 for training set were 0.9256 (95% CI, 0.8634-0.9879; all CRCs), 0.8708 (95% CI, 0.7709-0.9378; NLN) and 0.9804 (95% CI, 0.9585-0.9998; LNM), and for validation set were 0.9286 (95% CI, 0.8752-0.9820; all CRCs), 0.8911 (95% CI, 0.8238-0.9585; NLN), and 0.9833 (95% CI, 0.9642-1.002; LNM), respectively. Also, HOTTIP/PVT1/UCA1 panel dysregulation had a marked correlation with patient's OS in training set (logrank test P = 0.0121; hazard ratio [HR], 0.1225; 95% confidence interval [CI], 0.02376-0.6312), and in validation set (logrank test P < 0.0001, HR, 0.2003; 95% CI, 0.08942-0.4486). These data showed that the combination of HOTTIP, PVT1, and UCA1 as a predictive panel, has a better diagnostic performance than each of these lncRNAs individually, and could be used for the screening of patients with advanced CRC.

Positive correlation between interleukin-1 receptor antagonist gene 86bp VNTR polymorphism and colorectal cancer susceptibility: a case-control study.

Colorectal cancer (CRC) is one of the most common malignancies worldwide. Genetic variations in cytokine genes and their receptors lead to the severity of the disease. The interleukin-1 receptor antagonist (IL1RN) is a cytokine that inhibits interleukin-1 (IL-1) activity by binding to IL-1 receptors. Also, interleukin-4 (IL-4) is an anti-inflammatory cytokine that can play an important role in several cancers. The present case-control study was aimed to evaluate the association of IL-4 and IL1RN VNTR polymorphisms with the susceptibility to CRC in a sample of Iranian population provided by the Research Center for Gastroenterology and Liver Disease at Taleghani Hospital, Tehran. A total of 123 patients diagnosed with CRC and 152 healthy controls were recruited in the present study. Genomic DNA was extracted by salting out method from whole blood and genotyping of IL1RN and IL-4 VNTR polymorphisms were determined by PCR-based technology. Our study manifested the frequency of 1/2 and 2/4 genotypes of IL1RN 68bp VNTR polymorphism are significantly different between both groups (p = 0.0001 and p = 0.01 respectively). However, we could not find any correlation between IL-4 VNTR polymorphism and CRC cancer. It seems that 1/2 and 2/4 genotypes of IL1RN are correlated with CRC susceptibility in our population, although, more studies are needed to confirm our results.

MOLECULAR SURVEILLANCE OF Plasmodium vivax AND Plasmodium falciparum DHFR MUTATIONS IN ISOLATES FROM SOUTHERN IRAN.

In Iran, both Plasmodium vivax and P. falciparum malaria have been detected, but P. vivax is the predominant species. Point mutations in dihydrofolate reductase (dhfr) gene in both Plasmodia are the major mechanisms of pyrimethamine resistance. From April 2007 to June 2009, a total of 134 blood samples in two endemic areas of southern Iran were collected from patients infected with P. vivax and P. falciparum. The isolates were analyzed for P. vivax dihydrofolate reductase (pvdhfr) and P. falciparum dihydrofolate reductase (pfdhfr) point mutations using various PCR-based methods. The majority of the isolates (72.9%) had wild type amino acids at five codons of pvdhfr. Amongst mutant isolates, the most common pvdhfr alleles were double mutant in 58 and 117 amino acids (58R-117N). Triple mutation in 57, 58, and 117 amino acids (57L/58R/117N) was identified for the first time in the pvdhfr gene of Iranian P. vivax isolates. All the P. falciparumsamples analyzed (n = 16) possessed a double mutant pfdhfrallele (59R/108N) and retained a wild-type mutation at position 51. This may be attributed to the fact that the falciparum malaria patients were treated using sulfadoxine-pyrimethamine (SP) in Iran. The presence of mutant haplotypes in P. vivax is worrying, but has not yet reached an alarming threshold regarding drugs such as SP. The results of this study reinforce the importance of performing a molecular surveillance by means of a continuous chemoresistance assessment.