Diagnostic value of long noncoding RNA SNHG15 in gastric cancer: in vitro and in silico studies.

LncRNA SNHG15 has been recognized as the main factor in the progression of various cancer types. However, the underlying mechanisms are not well clarified. This research aimed to explore the diagnostic potential of SNHG15 in gastric cancer (GC) patients and also the effects of SNHG15-miRNA-mRNA network in GC pathobiology. The expression level of SNHG15 in GC tissues and adjacent normal tissues (ANTs) was evaluated by qRT-PCR and also considered in relation to clinicopathologic factors. The ROC curve was explored to consider the specificity and sensitivity of SNHG15. Gene ontology functional annotation and KEGG pathway analysis were performed in order to predict the effects of SNHG15-miRNA-mRNA network in GC pathobiology. SNHG15 was overexpressed in GC tissues compared to ANTs (fold change= 3.87 and P-value = 0.0022). The SNHG15 expression level was not significantly associated with clinicopathologic factors. ROC curve indicated the specificity of 63.51 and sensitivity of 79.73 and the AUC of 0.744 (P-value < 0.0001). Further gene network analysis revealed that SNHG15 interacts with has-miR-613, has-miR-542-3p, and has-miR-1236-3p, and may be involved in the GC pathobiology by affecting the EGFR tyrosine kinase inhibitor resistance, HIF-1 signaling pathway, and VEGF signaling pathway. It can be concluded that SNHG15 may be a diagnostic factor in GC and may contribute in a variety of cancer-related signaling pathways.

Clinical application of circulating tumor DNA in metastatic cancers.

INTRODUCTION: Advances in genomics have facilitated the application of cell-free DNA (cfDNA) and circulating tumor DNA (ctDNA) in phase II and phase III clinical trials. The various mutations of cfDNA/ctDNA have been correlated with clinical features. Advances in next-generation sequencing (NGS) and digital droplet PCR have paved the way for identifying cfDNA/ctDNA mutations. AREAS COVERED: Herein, the biology of ctDNA and its function in clinical application in metastasis, which may lead to improved clinical management of metastatic cancer patients, are comprehensively reviewed. EXPERT OPINION: Metastatic cancer ctDNA shows the greatest frequency of mutations in TP53, HER-2, KRAS, and EGFR genes (alteration frequency of > 50%). Therefore, identifying key mutations frequently present in metastatic cancers can help identify patients with pre-malignant tumors before cancer progression. Studying ctDNA can help determine the prognosis and select appropriate treatments for affected patients. Nevertheless, the obstacles to detecting and analyzing ctDNA should be addressed before translation into routine practice. Also, more clinical trials should be conducted to study the significance of ctDNA in commonly diagnosed malignancies. Given the recent advances in personalized anti-neoplastic treatments, further studies are needed to detect a panel of ctDNA and patient-specific ctDNA for various cancers.

Suppression of lncRNA NORAD may affect cell migration and apoptosis in gastric cancer cells.

BACKGROUND: Gastric cancer (GC) is a major malignancy that threatens people's lives worldwide. Long noncoding RNA (lncRNA) non-coding RNA activated by DNA damage (NORAD) is known to be a potential oncogene in many cancers and may promote cell migration and metastasis, and decrease apoptosis rate. MATERIAL AND METHODS: NORAD expression was measured in 70 pairs of GC tissues and their adjacent normal tissues (ANTs) by quantitative real-time polymerase chain reaction. Si-NORAD gene knockdown study and cellular assays were conducted to assess the correlation between NORAD expression and cell viability, apoptosis, migration, and metastasis. RESULTS: NORAD was significantly overexpressed in GC tissues compared to ANTs (P value < 0.0001). The receiver operating characteristic curve indicated the AUC of 0.721 with the sensitivity and specificity of 78.57 and 61.43, respectively (P value < 0.0001). NORAD downregulation leads to decreased cell viability (P value < 0.001) and migration (P value < 0.01), increased apoptosis rate (P value < 0.0001), and increased protein level for PTEN, E-cadherin, and Bax, but decreased protein level for Bcl-2. CONCLUSION: Generally, NORAD may serve as a potential diagnostic biomarker in GC.

Crosstalk between lncRNAs and miRNAs in gastrointestinal cancer drug resistance.

Gastrointestinal cancers are one of the most prevalent malignancies worldwide. Dysregulation of lncRNAs by epigenetic alteration is crucial in gastrointestinal carcinogenesis. Epigenetic alteration includes DNA methylation, chromatin remodeling, histone modifications, and deregulated-gene expression by miRNAs. LncRNAs are involved in biological processes, including, uncontrolled cell division, migration, invasion, and resistance to apoptosis and drugs. Multiple-drug resistance (MDR) is a crucial obstacle in effective chemotherapy for gastrointestinal cancers. MDR can be associated with the prognosis and diagnosis of patients receiving chemotherapeutic agents (i.e. cisplatin, oxaliplatin, platinum, 5-fluorouracil, gefitinib, methotrexate, taxol, cetuximab, docetaxel, and gemcitabine). In this review, we focused on recently known lncRNAs and their relation with miRNAs and chemotherapeutic drugs, and their modulation in gastrointestinal cancers. Moreover, we mentioned the future prospective and clinical application of lncRNAs as a critical indicator and biomarker in diagnosis, prognosis, staging, grading, and treatment of gastrointestinal cancers.

The emerging role of miR-200 family in metastasis: focus on EMT, CSCs, angiogenesis, and anoikis.

INTRODUCTION: Cancer is the second major threat to human society and one of the main challenges facing healthcare systems. One of the main problems of cancer care is the metastases of cancer cells that cause 90% of deaths due to cancer. Multiple molecular mechanisms are involved in cancer cell metastasis. Therefore, a better understanding of these molecular mechanisms is necessary for designing restrictive strategies against cancer cell metastasis. Accumulating data suggests that MicroRNAs (miRNAs) are involved in metastasis and invasion of human tumors through regulating multiple genes expression levels that are involved in molecular mechanisms of metastasis. The goal of this review is to present the molecular pathways by which the miR 200 family manifests its effects on EMT, cancer stem cells, angiogenesis, anoikis, and the effects of tumor cell metastases. METHODS: A detailed literature search was conducted to find information about the role of the miR-200 family in the processes involved in metastasis in various databases. RESULTS: Numerous lines of evidence revealed an association between the mir-200 family and metastasis of human tumors by impressing processes such as cancer stem cells, EMT, angiogenesis, and anoikis. CONCLUSIONS: Understanding the molecular mechanisms associated with metastasis in which the miR-200 family is involved can be effective in treating metastatic cancers.

Helicobacter pylori Infection and Dietary Factors Act Synergistically to Promote Gastric Cancer.

However, the incidence of gastric cancer (GC) has been decreased in past decades; GC is the second cause of cancer related death in the world. Evidence has illustrated that several factors including Helicobacter pylori (H. pylori) infection, host genetics, and environmental factors (smoking and particularly diet) may play a crucial role in gastric carcinogenesis. It has been demonstrated that high consumption of fresh fruits, vegetables, high level of selenium and zinc in drinking water, sufficient iron, and cholesterol protect against GC, while; smoked , pickled, and preserved foods in salt, and nitrites increase the risk of GC. Epidemiological studies have also proved that H. pylori infection and a high salt diet could independently induce atrophic gastritis and intestinal metaplasia. Recently, studies have been demonstrated that dietary factors directly influence H. pylori virulence. The use of appropriate diet could reduce levels of H. pylori colonization or virulence and prevent or delay development of peptic ulcers or gastric carcinoma. This is attractive from a number of perspectives including those of cost, treatment tolerability, and cultural acceptability. This review will describe new insights into the pathogenesis of H. pylori in relation to environmental factors, especially dietary, not only to find the developed means for preventing and treating GC, but also for understanding the role of chronic inflammation in the development of other malignancies.

Helicobacter pylori cag Pathogenicity Island cagL and orf17 Genotypes Predict Risk of Peptic Ulcerations but not Gastric Cancer in Iran.

BACKGROUND: Gastric cancer (GC) is the third most common cancer regarding mortality in the world. The cag pathogenicity island (PAI) of Helicobacter pylori which contains genes associated with a more aggressive phenotype may involve in the pathogenesis of gastrointestinal disease. We here aimed to examine the associations of cagH, cagL, orf17, and cagG genotypes of H. pylori cag PAI with severe gastrointestinal disease. MATERIALS AND METHODS: A total of 242 H. pylori strains were genotyped. Histopathological examination and classification of subjects were performed. RESULTS: The frequencies of the cagH, cagL, cagG, and orf17 genotypes were 40/54 (74.1%), 53/54 (98.1%), 38/54 (70.4%), and 43/54 (79.6%), respectively, in patients with peptidic ulceration (PU),while in the control group, the frequencies were 87/147 (59.6%) for cagH, 121/146 (82.9%) for cagL, 109/146 (74.7%) for cagG, and 89/146 (61.0%) for orf17. The results of simple logistic regression analysis showed that the cagL and orf17 genotypes were significantly associated with an increased risk of PU not GC; the ORs (95% CI) were 10.950 (1.446-82.935), and 2.504 (1.193-5.253), respectively. No significant association was found between the cagH and cagG genotypes and the risk of both the PU and the GC in Iran (P>0.05). Finally, multiple logistic regression analysis showed that the cagL genotype was independently and significantly associated with the age- and sex-adjusted risk for PU; the OR (95% CI) was 9.557 (1.219-17.185). CONCLUSIONS: We conclude that the orf17 and especially cagL genotypes of H. pylori cag PAI could be factors for risk prediction of PU, but not GC in Iran.

Active Immunization with Recombinant PilA protein Protects Against Pseudomonas aeruginosa Infection in a Mouse Burn Wound Model.

Pseudomonas aeruginosa as an opportunistic human pathogen that causes lethal infections in immunocompromised patients. Type IV pili are critical factors in virulence and colonization of P. aeruginosa in acute burn wound infection. The immunogenicity and efficacy of P. aeruginosa recombinant PilA (r-PilA) was evaluated in an experimental model of burn wound sepsis as a vaccine candidate. In this study, female C57BL/6 mice were divided into five groups. Mice in the experimental groups received either r-PilA vaccine alone or in combination with the alum adjuvant or complete Freund's adjuvant (CFA). Mice in the negative control group received phosphate-buffered saline (PBS). In order to characterize the response of Th1-Th2 to immunization, the cytokine profiles of spleen cells isolated from r-PilA immunized mice were investigated. Total IgG titers and isotopes were measured using ELISA method and finally, in order to study the systemic infection, bacterial titers in the liver, spleen and blood were also determined. Active immunization with r-PilA, which is followed by two booster shots, was sufficient to generate a robust immune response in mice. Cytokine analysis demonstrated the secretion of IL-4 and INF-É£ from splenocytes in response to in vitro antigen stimulation. The IgG response to r-PilA was a Th2 type response consis¬¬ting predominantly of the isotype IgG1 accompanied by lower levels of IgG2a. In conclusion, in this burned mouse model, vaccination with r-PilA can increase the humoral immunity, thereby leading to an effective protection against P. aeruginosa infection.