IL-2RG as a possible immunotherapeutic target in CRC predicting poor prognosis and regulated by miR-7-5p and miR-26b-5p.

Despite advances in treatment strategies, colorectal cancer (CRC) continues to cause significant morbidity and mortality, with mounting evidence a close link between immune system dysfunctions issued. Interleukin-2 receptor gamma (IL-2RG) plays a pivotal role as a common subunit receptor in the IL-2 family cytokines and activates the JAK-STAT pathway. This study delves into the role of Interleukin-2 receptor gamma (IL-2RG) within the tumor microenvironment and investigates potential microRNAs (miRNAs) that directly inhibit IL-2RG, aiming to discern their impact on CRC clinical outcomes. Bioinformatics analysis revealed a significant upregulation of IL-2RG mRNA in TCGA-COAD samples and showed strong correlations with the infiltration of various lymphocytes. Single-cell analysis corroborated these findings, highlighting IL-2RG expression in critical immune cell subsets. To explore miRNA involvement in IL-2RG dysregulation, mRNA was isolated from the tumor tissues and lymphocytes of 258 CRC patients and 30 healthy controls, and IL-2RG was cloned into the pcDNA3.1/CT-GFP-TOPO vector. Human embryonic kidney cell lines (HEK-293T) were transfected with this construct. Our research involved a comprehensive analysis of miRPathDB, miRWalk, and Targetscan databases to identify the miRNAs associated with the 3' UTR of human IL-2RG. The human microRNA (miRNA) molecules, hsa-miR-7-5p and hsa-miR-26b-5p, have been identified as potent suppressors of IL-2RG expression in CRC patients. Specifically, the downregulation of hsa-miR-7-5p and hsa-miR-26b-5p has been shown to result in the upregulation of IL-2RG mRNA expression in these patients. Prognostic evaluation of IL-2RG, hsa-miR-7-5p, and hsa-miR-26b-5p, using TCGA-COAD data and patient samples, established that higher IL-2RG expression and lower expression of both miRNAs were associated with poorer outcomes. Additionally, this study identified several long non-coding RNAs (LncRNAs), such as ZFAS1, SOX21-AS1, SNHG11, SNHG16, SNHG1, DLX6-AS1, GAS5, SNHG6, and MALAT1, which may act as competing endogenous RNA molecules for IL2RG by sequestering shared hsa-miR-7-5p and hsa-miR-26b-5p. In summary, this investigation underscores the potential utility of IL-2RG, hsa-miR-7-5p, and hsa-miR-26b-5p as serum and tissue biomarkers for predicting CRC patient prognosis while also offering promise as targets for immunotherapy in CRC management.

The impact of COVID-19 on national program of colorectal cancer screening in Tehran, Iran: a multicenter study.

BACKGROUND: The COVID-19 pandemic has affected all aspects of the healthcare system, including prevention, treatment, rehabilitation of diseases and health education; access to essential therapies; allocation of finance & facilities to health issues, and governance of diseases, including COVID-19 and other diseases. Consequently, the burden of COVID-19 was not only attributable to the multiorgan involvement and detailed presentation of the disease but also to the inadequate management of other diseases resulting from the exclusive allocation of resources and medical personnel to the pandemic crisis. Over the mentioned period, one observed deficiency was the lack of public and official favor for conventional screening protocols. To this end, this study aims to evaluate the impact of the COVID-19 pandemic on colorectal cancer (CRC) screening protocols at Shahid Beheshti University of Medical Sciences in Tehran, Iran, in an effort to identify individuals at risk for CRC and provide them with intensive screening and therapy. METHODS: This is an observational study comparing the number of candidates for CRC screening referred to primary, secondary, and tertiary health-care centers under supervision of Shahid Beheshti University of Medical Sciences (SBMU), Tehran, Iran in a 2-year interval before and after COVID-19 pandemics. Patients with intermediate- and high-risk criteria for colorectal cancer were included in the study and were screened by fecal immunochemical test. Patients with positive or indeterminate fecal test results were further evaluated with colonoscopy in research institute for gastroenterology and liver diseases where is a tertiary referral center for CRC screening. Finally, the decrease percentage of screening tests and endoscopic findings during the pandemic period compared to pre-pandemic period was calculated and interpreted. RESULTS: A significant decrease in the number of performed fecal immunochemical tests (FITs), referred positive FITs, and referred patients with positive alarm signs to the Research Institute of Gastroenterology and Liver Diseases (RIGLD) center inevitably led to a considerable decrease in the number of endoscopic findings, including high-risk adenomas, sessile serrated polyps, and even early-stage colorectal cancers (CRCs). CONCLUSION: The disruption of screening protocols caused by the COVID-19 pandemic appears to increase the number of patients with high-grade and end-stage CRCs referred in the near future.

Correlated downregulation of VDR and CYP3A4 in colorectal cancer.

BACKGROUND: The evidence obtained from experimental studies suggests the tumor-suppressive effects of vitamin D by controlling the differentiation, proliferation, and apoptosis in cancerous cells. Furthermore, the deregulation of genes involved in vitamin D metabolism has been reported in several types of cancer. METHODS: In the present study, we investigated the expression level of vitamin D metabolic pathway genes, including VDR, CYP3A4, RXRα, and GC, in colorectal cancer (CRC) samples compared with the adjacent tissues by using quantitative RT-PCR. RESULTS: The results indicated significant downregulation of CYP3A4 and VDR genes in CRC tissues compared with the adjacent control tissues (p < 0.01). RXRA and GC expression levels did not show any significant alteration among the studied samples. Moreover, a positive correlation was observed between the expression level of CYP3A4 and VDR genes (p < 0.0001). ROC curve analysis also revealed the potential diagnostic power of CYP3A4 and VDR genes in CRC samples. CONCLUSION: Reduction in the expression of both CYP3A4 and VDR plays an important role in CRC due to the possible impairment in vitamin D metabolism. Further studies concerning the relationship between the expression of these genes and colorectal cancer pathogenesis and treatment are recommended.

Long non­coding RNA LINC00460 contributes as a potential prognostic biomarker through its oncogenic role with ANXA2 in colorectal polyps.

BACKGROUND: Long intergenic non-coding RNA 460 (LINC00460) as a potential oncogene and Annexin A2 (ANXA2) as a promoter in different cancer progression processes was considered. A significant relationship between the LINC00460 and ANXA2 has been recently discovered in colorectal cancer (CRC). Therefore, defining molecular biomarkers accompanied by lesion histopathologic features can be a suggestive prognostic biomarker in precancerous polyps. This study aimed to investigate the elusive expression pattern of ANXA2 and LINC00460 in polyps. MATERIALS AND METHODS: The construction of the co-expression and correlation network of LINC00460 and ANXA2 was plotted. LINC00460 and ANXA2 expression in 40 colon polyps was quantified by reverse transcription-real-time polymerase chain reaction. The receiver operating characteristic (ROC) curve was designed for distinguishing the high-risk precancerous lesion from the low-risk. Further, bioinformatics analysis was applied to find the shared MicroRNA-Interaction-Targets (MITs) between ANXA2 and LINC00460, and the associated pathways. RESULTS: ANXA2 has a high co-expression rank with LINC00460 in the lncHUB database. Overexpression of ANXA2 and LINC00460 was distinguished in advanced adenoma polyps compared to the adjacent normal samples. The estimated AUC for ANXA2 and LINC00460 was 0.88 - 0.85 with 93%-90% sensitivity and 81%-70% specificity. In addition, eight MITs were shared between ANXA2 and LINC00460. Enrichment analysis detected several GO terms and pathways, including HIF-1α associated with cancer development. CONCLUSION: In conclusion, the expression of the ANXA2 and LINC00460 were significantly elevated in pre-cancerous polyps, especially in high-risk adenomas. Collectively, ANXA2 and LINC00460 may be administered as potential prognostic biomarkers in patients with a precancerous large intestine lesion as an alarming issue.

Identification of antisense and sense RNAs of intracrine fibroblast growth factor components as novel biomarkers in colorectal cancer and in silico studies for drug and nanodrug repurposing.

INTRODUCTION: Colorectal cancer (CRC) is one of the most malignant tumors and in which various efforts for screening is inconclusive.The intracrine FGF panel, the non-tyrosine kinase receptors (NTKR) FGFs and affiliated antisenses play a pivotal role in FGF signaling.The expression levels of coding and non-coding intracrine FGFs were assessed in CRC donors.Also, substantial costs and slow pace of drug discovery give high attraction to repurpose of previously discovered drugs to new opportunities. OBJECTIVES: The aim of present study was to evaluate the potential role of the coding and non-coding intracrine FGFs as a new biomarkers for CRC cases and defining drug repurposing to alleviate FGF down regulation. METHODS: RNA-seq data of colon adenocarcinomas (COAD) was downloaded using TCGA biolinks package in R.The DrugBank database (https://go.drugbank.com/) was used to extract interactions between drugs and candidate genes. A total of 200 CRC patients with detailed criteria were enrolled.RNAs were extracted with TRIzol-based protocol and amplified via LightCycler® instrument.FGF11 and FGF13 proteins validation was performed by used of immunohistochemistry technique in tumor and non-tumoral samples.Pearson's correlation analysis and ROC curve plotted by Prism 8.0 software. RESULTS: RNA-seq data from TCGA was analyzed by normalizing with edgeR.Differentially expressed gene (DEG) analysis was generated. WCC algorithm extracted the most significant genes with a total of 47 genes. Expression elevation of iFGF antisenses (12AS,13As,14AS) compared with the normal colon tissue were observed (P = 0.0003,P = 0.042,P = 0.026, respectively). Moreover,a significant decrease in expression of the corresponding sense iFGF genes was detected (P < 0.0001).Plotted receiver operating characteristic (ROC) curves for iFGF components' expression showed an area of over 0.70 (FGF11-13: 0.71% and FGF12-14: 0.78%, P < 0.001) for sense mRNA expression, with the highest sensitivity for FGF12 (92.8%) and lowest for FGF11 (61.41%).The artificial intelligence (AI) revealed the valproic acid as a repurposing drug to relief the down regulation of FGF12 and 13 in CRC patients. CONCLUSION: Intracrine FGFs panel was down regulated versus up regulation of dependent antisenses. Thus, developing novel biomarkers based on iFGF can be considered as a promising strategy for CRC screening.In advanced, valporic acid detected by AI as a repurposing drug which may be applied in clinical trials for CRC treatment.

Association of HOTAIR rs2366152 and rs1899663 polymorphisms with colorectal cancer susceptibility in Iranian population: A case-control study.

BACKGROUND: Despite the fact that numerous studies have investigated the association between genetic polymorphisms and colorectal cancer (CRC), more research is required to comprehend the molecular mechanisms of CRC. In the present study, we investigated the association between lncRNA HOTAIR rs2366152 and rs1899663 polymorphisms with CRC susceptibility in the Iranian population. METHODS: This case-control study consisting of 187 CRC patients and 200 healthy samples. The tetra-amplification refractory mutation system-polymerase chain reaction (Tetra-ARMS-PCR) technique was used for the genotyping of rs2366152 and rs1899663 polymorphisms. RESULTS: The findings showed that the AG genotype of the rs2366152 polymorphism has a protective effect on CRC susceptibility (OR = 0.60, 95% CI: 0.38-0.94, p-value = 0.023). Furthermore, rs2366152 polymorphism associated with CRC risk in an over dominant inheritance model (p-value = 0.0089). According to the outcomes of the rs1899663 polymorphism, the GT genotype had protective effects on CRC risk (OR = 0.55, 95% CI: 0.35-0.86, p-value = 0.008). Moreover, statistical analysis has shown that the rs1899663 polymorphism was associated with CRC risk in dominant (p-value = 0.013) and overdominant (p-value = 0.0086) inheritance models in the Iranian population. CONCLUSION: This study confirmed that HOTAIR rs2366152 and rs1899663 polymorphisms associated with CRC risk in different inheritance models. It is indeed necessary to do additional research to verify our findings.

Up regulation of long non-coding RNAs BACE1 and down regulation of LINC-PINT are associated with CRC clinicopathological characteristics.

BACKGROUND: Long non-coding RNAs (LncRNAs) are known to have regulatory consequences for aberrant gene expression in cancers. The aim of this study was to evaluate the expression levels of long non-encoding RNAs, BACE1 (ß-secretase1) and LINC-PINT (Long Intergenic Non-Protein Coding RNA, P53 Induced Transcript), in colorectal cancer (CRC) with clinicopathological parameters. METHODS AND RESULTS: Bioinformatics analysis defining effectual signalling pathways Wnt. A total of 130 tissue samples (50 fresh CRC tissues with parallel adjacent normal tissues (ADJ) accompanied with 30 normal healthy control tissue samples) were collected from the Iranian population. mRNA expression analysis was performed via Real Time Q-PCR. Statistical analysis for comparing CRC expression levels with ADJ and normal healthy tissues were carried out using Kruskal-Wallis tests. The Receiver Operating Characteristic (ROC) curve was plotted for each LNC, separately. We discovered that PINT and BACE1 expression levels were decreased and increased respectively in CRC tumour samples compared with ADJ normal and healthy tissues. Clinicopathological parameter assessment revealed a significant relationship between PINT expression, tumour location, staging and distant metastasis (p < 0.009, p < 0.014, p < 0.008, respectively). Also, BACE1 over expression was significantly associated with tumour site (p < 0.009), metastasis (p < 0.017) and histological differentiation (p < 0.028) and staging (p < 0.017). Furthermore, ROC curve plotting showed LINC-PINT LNC-BACE1 may distinguish between early and late-stage of CRC, highlighting the value of both BACE1 and PINT as CRC progression biomarkers. CONCLUSION: We investigated two LNCRNAs (PINT and BACE1) as potential CRC prognostic biomarkers, which are imperative for early and effective medical intervention in CRC. Expression levels of PINT and BACE1 in CRC tissue samples may serve to identify metastasis earlier, increasing patient survival rates and expediating clinical treatment options.

High expression of ZEB1 is associated with EMAST & metastasis in colorectal cancer patients.

Background & objectives: Transforming growth factor-beta (TGF-ß) signalling pathway has been reported to be involved in metastasis and at the same time has been considered compellingly an important mediator of epithelial-to-mesenchymal transition (EMT). Besides, EMT process is maintained by zinc-finger E-box-binding homeobox 1 (ZEB1) gene which is induced by TGF-ß pathway. TGF-ß has been shown to be associated with elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) phenomenon, which is one of the prognostic biomarkers of colorectal cancer (CRC). This study was conducted to determine the link among ZEB1-induced TGF-ß, EMAST status and metastasis. Methods: The expression level of ZEB1 was evaluated using quantitative reverse transcription (qRT) real-time PCR in 122 formalin fixed paraffin-embedded tissues of CRC sample with known EMAST status and TGF-ß/Smad-dependent pathways. The association among ZEB1 expression, TGF-ß signalling pathway, EMAST status and metastatic behaviour was examined. Results: ZEB1 gene expression level was higher in tumour tissues as compared to normal samples (P<0.045). In addition, ZEB1 positive expression level was associated significantly with metastasis (P=0.05), EMAST+ status (P=0.052) and activated TGF-ß signalling pathway (P=0.002). Interpretation & conclusions: Our results validated significant association between activated TGF-ß signalling pathway and EMAST+ phenotype with higher expression of ZEB1 and higher level of metastasis.

Autophagy ATG16L1 rs2241880 impacts the colorectal cancer risk: A case-control study.

BACKGROUND: Despite many efforts to discover the important role of the autophagy process in the pathogenesis of colorectal cancer (CRC), the exact involved molecular mechanism still remains to be elucidated. Recently, a limited number of studies have been employed to discover the impact of autophagy genes' variants on the development and progression of CRC. Here, we evaluated the association between two single-nucleotide polymorphisms (SNPs) in the main components of the autophagy genes, ATG16L1 rs2241880, and ATG5 rs1475270, and the CRC risk in an Iranian population. METHODS: During this investigation, a total of 369 subjects, including 179 CRC patients and 190 non-cancer controls have been genotyped using Tetra-primer amplification refractory mutation system-polymerase chain reaction (TP-ARMS-PCR) method. RESULT: The results demonstrated that the T allele of the ATG16L1 rs2241880 was significantly associated with the increased risk of CRC in the studied population (OR 1.64, 95% CI: 1.21-2.22, p = 0.0015). Moreover, ATG16L1 rs2241880 TT genotype increased the susceptibility to CRC (OR 3.31, 95% CI: 1.64-6.69, p = 0.0008). Furthermore, a significant association was observed under the recessive and dominant inheritance models (p = 0.0015 and p = 0.017, respectively). No statistically significant differences were found in the ATG5 rs1475270 alleles and genotypes between the cases and controls. CONCLUSION: The results of the present study may be helpful concerning the risk stratification in CRC patients based on the genotyping approach of autophagy pathways and emphasize the need for further investigations among different populations and ethnicities to refine our conclusions.

Novel long noncoding RNAs upregulation may have synergistic effects on the CYP24A1 and PFDN4 biomarker role in human colorectal cancer.

Long noncoding RNAs (lncRNAs) are emerging as the master regulators of tumor initiation, proliferation, and metastasis; however, their diagnostic value as potential biomarkers should be clarified. Vitamin D influences the expression of several genes in various pathways, including the CYP24A1 gene in the vitamin D metabolism pathway. In the present research, we surveyed the expression levels and clinical significance of novel lncRNAs related to CYP24A1 and PFDN4 genes in colorectal cancer (CRC) using real-time polymerase chain reaction. Furthermore, we assessed the expression of these genes after vitamin D treatment in HCT-116 and HT-29 colon cancer cell lines. Our results indicated that the transcription of CYP24A1, PFDN4, and nearby lncRNAs was affected by vitamin D treatment in HCT-116 and HT-29 cell lines. Moreover, CYP24A1, PFDN4, lnc-CYP24A1-3:1, and lnc-TSHZ2-19:1 were upregulated and had the potential to distinguish colorectal cancer tissues from the adjacent tissues by the large area under the receiver operating characteristic curve (0.94, 0.66, 0.70, and 0.60, respectively). lnc-TSHZ2-19:1 expression level significantly correlated with gender (p = .03). In conclusion, CYP24A1, PFDN4, lnc-CYP24A1-3:1, and lnc-TSHZ2-19:1 can be used as potential diagnostic biomarkers in the specific and sensitive assessment of CRC. Besides this, vitamin D treatment may modulate the expression of these genes in a cell-specific manner.

The effective function of circular RNA in colorectal cancer.

Colorectal cancer (CRC) is the 3rd most common type of cancer worldwide. Late detection plays role in one-third of annual mortality due to CRC. Therefore, it is essential to find a precise and optimal diagnostic and prognostic biomarker for the identification and treatment of colorectal tumorigenesis. Covalently closed, circular RNAs (circRNAs) are a class of non-coding RNAs, which can have the same function as microRNA (miRNA) sponges, as regulators of splicing and transcription, and as interactors with RNA-binding proteins (RBPs). Therefore, circRNAs have been investigated as specific targets for diagnostic and prognostic detection of CRC. These non-coding RNAs are also linked to metastasis, proliferation, differentiation, migration, angiogenesis, apoptosis, and drug resistance, illustrating the importance of understanding their involvement in the molecular mechanisms of development and progression of CRC. In this review, we present a detailed summary of recent findings relating to the dysregulation of circRNAs and their potential role in CRC.

Toward finding the difference between untreated celiac disease and COVID-19 infected patients in terms of CD4, CD25 (IL-2 Rα), FOXP3 and IL-6 expressions as genes affecting immune homeostasis.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is defined as an emerging infectious disease caused by severe acute respiratory syndrome coronavirus 2 and celiac disease (CD) is one of the autoimmune multiorgan diseases, which can be accompanied by an increased risk of viral infections. CD patients, especially untreated subjects, may be at greater risk of infections such as viral illnesses. Interleukin (IL)-6, CD4, CD25, and FOXP3 are known as genes affecting immune homeostasis and relate to the inflammation state. This study aimed to compare the expression levels of aforementioned genes in peripheral blood samples of CD and severe COVID-19 patients. METHODS: Sixty newly diagnosed CD patients with median age (mean ± SD) of 35.40 ± 24.12 years; thirty confirmed severe COVID-19 patients with median age (mean ± SD) of 59.67 ± 17.22, and 60 healthy subjects with median age (mean ± SD) of 35.6 ± 13.02 years; were recruited from March to September 2020. Fresh whole blood samples were collected, total RNA was obtained and cDNA synthesis was carried out. RNA expression levels of IL-6, CD4, CD25, and FOXP3 genes were assessed using real-time quantitative RT-PCR according to the 2-∆∆Ct formula. Statistical analysis was performed using SPSS (V.21) and GraphPad, Prism (V.6). RESULTS: While increased expression of CD4, CD25, and FOXP3 was observed in CD patients compared to the control group (p = 0.02, p = 0.03, and p < 0.0001 respectively) and COVID-19 patients group (p < 0.0001 for all of them), their expression levels in COVID-19 patients decreased compared to controls (p < 0.0001, p = 0.01, p = 0.007, respectively). Increased IL-6 expression was observed in both groups of patients compared to controls (p < 0.0001 for both of them). CONCLUSIONS: Although untreated CD patients may be at greater risk of developing into severe COVID-19 if they are infected by SARS-CoV-2 virus (due to their high expression of IL-6), increased expression of anti-inflammatory markers in these patients may be beneficial for them with the ability of reducing the severity of COVID-19 disease, which needs to be proven in future studies involving celiac patients infected with COVID-19.

Dysregulation of vitamin D synthesis pathway genes in colorectal cancer: A case-control study.

BACKGROUND: The cytochromes P450 are a superfamily of enzymes that control the synthesis of the biologically active form of vitamin D, 1,25-dihydroxyvitamin D3. These enzymes contribute to the formation of 1,25-dihydroxyvitamin D3, which starts with a 25-hydroxylation by CYP2R1 and CYP27A1 and a subsequent 1α-hydroxylation via CYP27B1. METHODS: By using quantitative real-time polymerase chain reaction (qRT-PCR), we analyzed the expression ratio of CYP2R1, CYP27A1 and CYP27B1 genes within the vitamin D metabolic pathway in a total of 75 colorectal cancer (CRC) tissues compared to the adjacent tissues. Furthermore, we evaluated the association of CYP27B1 rs4646536 and CYP2R1 rs12794714 and rs10766196 polymorphisms with CRC risk in a total of 490 subjects, including 245 CRC patients and 245 non-cancer controls. The genotyping was performed using tetra-primer amplification refractory mutation system polymerase chain reaction (TP-ARMS-PCR) method. RESULTS: The results indicated 2.3 and 2.7 upregulation of CYP2R1 and CYP27B1 genes in colorectal cancer tissues compared to the adjacent tissues, respectively. Rs12794714 AG genotype increased the risk of CRC (P = .03). Furthermore, a significant association was observed under the dominant inheritance model (P = .039). CONCLUSION: CYP2R1 and CYP27B1 genes were over-expressed in CRC samples compared to the adjacent control tissues. Furthermore, CYP2R1 rs12794714 variant was associated with the risk of CRC in the studied samples. CYP2R1 rs10766196 and CYP27B1 rs4646536 are not responsible for CYP2R1 and CYP27B1 genes expression alteration, respectively, but CYP2R1 rs12794714 polymorphism may be the reason of CYP2R1 upregulation and increased the risk of CRC.

Identification of a stool long non-coding RNAs panel as a potential biomarker for early detection of colorectal cancer.

BACKGROUND: The feces of colorectal cancer (CRC) patients contain tumor colonocytes, which constantly shed into the lumen area. Therefore, stool evaluation can be considered as a rapid and low-risk way to directly determine the colon and rectum status. As long non-coding RNAs (lncRNAs) alterations are important in cancer cells fate regulation, we aimed to assess the level of a panel of cancer-related lncRNAs in fecal colonocytes. METHODS: The population study consisted of 150 subjects, including a training set, a validation set, and a group of 30 colon polyps. The expression levels of lncRNAs were evaluated by quantitative real-time PCR (qRT-PCR). The NPInetr and EnrichR tools were used to identify the interactions and functions of lncRNAs. RESULTS: A total of 10 significantly dysregulated lncRNAs, including CCAT1, CCAT2, H19, HOTAIR, HULC, MALAT1, PCAT1, MEG3, PTENP1, and TUSC7, were chosen for designing a predictive panel. The diagnostic performance of the panel in distinguishing CRCs from the healthy group was AUC: 0.8554 in the training set and 0.8465 in the validation set. The AUC for early CRCs (I-II TNM stages) was 0.8554 in the training set and 0.8465 in the validation set, and for advanced CRCs (III-IV TNM stages) were 0.9281 in the training set and 0.9236 in the validation set. The corresponding AUC for CRCs vs polyps were 0.9228 (I-IV TNM stages), 0.9042 (I-II TNM stages), and 0.9362 (III-IV TNM stages). CONCLUSIONS: These data represented the application of analysis of fecal colonocytes lncRNAs in early detection of CRC.

EMAST status as a beneficial predictor of fluorouracil-based adjuvant chemotherapy for Stage II/III colorectal cancer.

BACKGROUND: Elevated microsatellite alteration at selected tetranucleotide repeats (EMAST) is a type of microsatellite instability that occurs in ∼60% of colorectal cancers (CRCs) and associated with MSH3 dysfunction. A 5-fluorouracil (5-FU)-related cytotoxicity is attenuated in MSH3-deficient colon cancer cells. Reported here is the predictive value of EMAST in CRCs with Stage II or III disease treated with 5-FU-based chemotherapy. METHODS: EMAST status was analyzed in 157 patients with CRC with Stage II or III disease and MSH3 expression was analyzed using immunohistochemistry. The patients treated with 5-FU-based chemotherapy were studied in terms of the links of EMAST status with MSH3 expression, clinicopathological features, and overall survival (OS). RESULTS: A total of 63 patients (40.1%) had EMAST positive (EMAST+ ) CRC and 77 patients (49.0%) had low MSH3 expression. EMAST+ tumors were associated with advanced TNM stage and poor and moderately differentiated tumor. EMAST CRC was more frequently observed in tumors with low expression of MSH3 in the nucleus (n = 53; 84.1%, p < .001). On multivariate analysis, patients with EMAST+ status had a worse OS (hazard ratio: 2.489, 95% confidence interval [1.149-5.394], and p = .021). Worse OS in EMAST+ patients who received 5-FU-based chemotherapy was significantly more common compared with EMAST- CRCs. CONCLUSION: There is a link between EMAST and reduced nuclear expression of MSH3. There is worse survival in patients with EMAST+ CRC after 5-FU-based chemotherapy. According to our findings, adjuvant 5-FU-based chemotherapy might not be advantageous in EMAST+ CRCs with Stage II or III disease.

miR-298 plays a pivotal role in colon cancer invasiveness by targeting PTEN.

Evidence indicate that the miR-298 dysregulation might associate with colorectal cancer (CRC) development. Herein, we evaluated the effect of miR-298 dysregulation on colon cancer invasiveness. First, metabolic activity, cell cycle progression, apoptosis, and invasion of miR-298 overexpressed/knocked out colon cancer cells were examined and combined with their transcriptome analysis data for better visualization of miR-298 intracellular signaling networks. Interaction between miR-298 and its target was evaluated with luciferase assay and validated using western blot analysis. The proportion of abnormal miR-298 level was investigated in tumor samples, matched normal adjacent tissues, and plasmas of 100 CRC patients, and also compared with 100 normal plasma samples. The Mann-Whitney U test was performed to assess miR-298 differences among the studied groups, and the correlation between miR-298 and the risk of CRC was shown by univariate and multivariate logistic regression. The data indicate that miR-298 overexpression promoted proliferation and metastasis in CRC cells via targeting phosphatase and tensin homolog. Comparative analysis of CRC tumors, normal adjacent tissues, and plasmas indicated a significant miR-298 upregulation in tumors and plasmas (1.72-fold and 1.65-fold, respectively; p < .001). Also, the aberrant level of miR-298 contributed with CRC tumor differentiation, TNM stage and lymph node metastasis (p < .001), and independently associated with poor survival of CRC patients (p < .029; hazard ratio: 1.292; 95% confidence interval: 0.339-2.184). Collectively, these data showed that abnormal level of miR-298 correlated with cancer development and through that lowered the overall survival rate of CRC patients. Therefore, miR-298 could be considered as a therapeutic target for CRC.

MSI-L/EMAST is a predictive biomarker for metastasis in colorectal cancer patients.

BACKGROUND: Microsatellite instability (MSI) is a prognostic marker in colorectal cancer (CRC). The biological significance of MSI-low (MSI-L) phenotype and its differences with microsatellite stable (MSS) phenotype remains unclear. The aim of this study is indicating the role of mononucleotide repeat in identifying MSI-L and revealing the association of MSI-L with elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) and oncologic outcome in CRC patients. METHODS: MSI and EMAST status were analyzed using three quasimonomorphic panel (BAT-25, BAT-26, and NR-27) and five tetranucleotide repeats (D20S82, D20S85, D9S242, D8S321, and MYCL1), respectively, by capillary electrophoresis method without the need to fluorescent primers. The associations of MSI status with clinicopathological features, EMAST status, metastasis, and overall survival (OS) were investigated. RESULTS: Among 159 CRC patient 22.0% were MSI-H, 40.3% were MSS, 37.7% were MSI-L, and 41.5% showed EMAST + phenotype. MSI-L were associated with advanced stages, EMAST+ tumors and worse OS ( p ≤ 0.001). Metastasis was relatively common in MSI-L/EMAST + CRCs and BAT-25 were the most unstable marker in these tumors. CONCLUSIONS: MSI-L tumors have different clinicopathological features from MSS and MSI-H tumors. The MSI-L phenotype is a worse prognostic biomarker in CRC and when accompanied by EMAST could be a predictor for metastasis.

HER2+ mCRC patients with exon 20 R784G substitution mutation do not respond to the cetuximab therapy.

The human epidermal growth factor 2 (HER2) gene undergoes various mutations that could alter its activity or respond to the antibody therapies. Cetuximab, a known anti-EGFR monoclonal antibody (mAB), is widely administered in metastatic colorectal cancer (mCRC) cases. Here we identified mCRC patients who did not respond to cetuximab (500 mg/m2 , q2w) after fluoropyrimidine/oxaliplatin regimen failure. Tumor samples were examined with immunohistochemistry for protein distribution, polymerase chain reaction (PCR) sequencing for mutation detection and real-time PCR for mRNA expression pattern analysis between cetuximab sensitive and resistance patients. The conformational differences of normal and mutated protein structures were predicted by bioinformatics analysis. The 5-year survival rates of target groups were estimated using the Kaplan-Meier method. Immunohistochemistry showed that all cases had high level of HER2 protein. No K-Ras or B-Raf mutation was observed among the study population; however, cetuximab resistance patients harbored a somatic mutation R784G at the exon 20 region of HER2 coding sequence. According to bioinformatics analysis, this mutation caused a notable misfold in protein conformation. Meanwhile, survival analysis showed R784G mutated mCRC patients had shortened survival rate compared with the mCRC cases with wild-type HER2. Collectively, these data report a new mechanism of resistance to cetuximab and might be applicable in modifying new therapeutic strategies for HER2 involved cancers.

Intratumoral infiltrating lymphocytes correlate with improved survival in colorectal cancer patients: Independent of oncogenetic features.

BACKGROUND: The clinical relevance and prognostic value of tumor-infiltrating lymphocytes (TILs) as an interplay between malignant cells and immune function has been known for decades. On contrary, this potential may be different by T lymphocytes subsets endowed with a different function. Colorectal cancer (CRC) is a heterogeneous disease with different suggested prognostic biomarkers. So, this study was conducted to examine the prognostic value of CD8+ TILs on the survival rate of CRC as an independent factor of oncogenetic tumor features. METHODS: With respect to this, 281 formalin-fixed, paraffin-embedded tissue samples of Iranian CRC patients were evaluated for clinical features including tumor location, tumor stage, differentiation grade, and mucinous characteristics. Then, using the standard immunohistochemical technique, tumor sections were examined, and CD8+ TILs were counted and identified in two regions of the tumor, including intratumoral (ITCIL TILs) and stromal (S TILs). The prognostic value of CD8+ TILs was determined by comparing with parameters, such as diagnostic age, tumor stage, adjuvant therapy, microsatellite instability (MSI) status, KRAS and BRAF mutations, family history, and survival. RESULTS: The presence of intratumoral tumor cell-infiltrating lymphocytes (ITCIL) CD8+ lymphocytes are significantly associated with differentiation (p = 0.004), tumor, node, and metastases (TNM) stage (p = 0.001), and MSI (p = 0.001). Meanwhile, based on the level of stromal infiltrating lymphocytes (SIL) infiltration, analysis of CRC patients was statistically associated with a location (p = 0.002), TNM stage (p < 0.001), metastasis (p < 0.001), and KRAS mutation (p = 0.031). Also, tumors with severe ITCIL CD8+ lymphocytes have a good prognosis compared with tumors with poor or moderate ITCIL CD8+ lymphocytes. CONCLUSIONS: These results suggest that intratumor cell-infiltrating CD8- T lymphocytes as an independent prognostic factor that have an antitumor activity as judged by their favorable effect on patients' survival and could potentially be exploited in the treatment of CRC.

miR-30a promoter variation contributes to the increased risk of colorectal cancer in an Iranian population.

Cytochrome P450 family 24 subfamily A member 1 (CYP24A1) gene is overexpressed in many cancers including colorectal cancer (CRC) and correlated with tumor invasion, lymph node metastasis, and the reduced overall survival. We predicted that miR-30a and miR-125a regulate the CYp24A1 gene expression. Therefore, we performed a case-control study using 800 individuals, including 389 patients with CRC and 411 noncancer controls to evaluate the association between miR-30a rs2222722 and miR-125a rs12976445 polymorphisms, located at in the promoter region, and the risk of sporadic CRC in an Iranian population. The genotyping assay for both polymorphisms was performed using Tetra-primer amplification refractory mutation systems polymerase chain reaction. The results indicated that the frequency of the miR-30a rs2222722 CT genotype was significantly different in the studied groups ( P = 0.0001; odds ratio [OR] = 1.9; 95% confidence interval [CI], 1.39-2.60). Also, a significant difference was observed under the dominant inheritance model ( P = 0.0001; OR = 1.8; 95% CI, 1.33-2.43). The frequency of the miR-30a rs2222722 T allele was significantly associated with increased CRC risk in the studied population ( P = 0.0019; OR = 1.47; 95% CI, 1.15-1.89). Taken together, our study provides preliminary evidence that the rs2222722 polymorphism increases the susceptibility to CRC in an Iranian population. Therefore, the affecting factors on CYP24A1 gene expression such as microRNAs can be considered as risk factors for CRC.