Emerging molecular functions of microRNA-9: Cancer pathology and therapeutic implications

BRAF mutation, selected miRNAs and genes expression in primary papillary thyroid carcinomas and local lymph node metastases

Mutations in cancer-related genes are now known to be accompanied by epigenetic events in carcinogenesis by modification of the regulatory pathways and expression of genes involved in the pathobiology. Such cancer-related mutations, miRNAs and gene expression may be promising molecular markers of the most common papillary thyroid carcinoma (PTC). However, there are limited data on their relationships. The aim of this study was to analyse the interactions between BRAF mutations, selected microRNAs (miR-21, miR-34a, miR-146b, and miR-9) and the expression of selected genes (LGALS3, NKX2-1, TACSTD2, TPO) involved in the pathogenesis of PTC. The study cohort included 60 primary papillary thyroid carcinomas (PTC) that were classified as classical (PTC/C; n=50) and invasive follicular variant (PTC/F; n=10), and 40 paired lymph node metastases (LNM). BRAF mutation status in primary and recurrent/persistent papillary thyroid carcinomas was determined. The mutation results were compared both between primary and metastatic cancer tissue, and between BRAF mutation status and selected genes and miRNA expression in primary PTC. Furthermore, miRNAs and gene expression were compared between primary PTCs and non-neoplastic tissue, and local lymph node metastatic tumor, respectively. All studied markers showed several significant mutual interactions and contexts. In conclusion, to the best our knowledge, this is the first integrated study of BRAF mutational status, the expression levels of mRNAs of selected genes and miRNAs in primary PTC, and paired LNM.

MiRNA dysregulation underlying common pathways in type 2 diabetes and cancer development: an Italian Association of Medical Oncology (AIOM)/Italian Association of Medical Diabetologists (AMD)/Italian Society of Diabetology (SID)/Italian Society of Endocrinology (SIE)/Italian Society of Pharmacology (SIF) multidisciplinary critical view

Increasing evidence suggests that patients with diabetes, particularly type 2 diabetes (T2D), are characterized by an increased risk of developing different types of cancer, so cancer could be proposed as a new T2D-related complication. On the other hand, cancer may also increase the risk of developing new-onset diabetes, mainly caused by anticancer therapies. Hyperinsulinemia, hyperglycemia, and chronic inflammation typical of T2D could represent possible mechanisms involved in cancer development in diabetic patients. MicroRNAs (miRNAs) are a subset of non-coding RNAs, ⁓22 nucleotides in length, which control the post-transcriptional regulation of gene expression through both translational repression and messenger RNA degradation. Of note, miRNAs have multiple target genes and alteration of their expression has been reported in multiple diseases, including T2D and cancer. Accordingly, specific miRNA-regulated pathways are involved in the pathogenesis of both conditions. In this review, a panel of experts from the Italian Association of Medical Oncology (AIOM), Italian Association of Medical Diabetologists (AMD), Italian Society of Diabetology (SID), Italian Society of Endocrinology (SIE), and Italian Society of Pharmacology (SIF) provide a critical view of the evidence about the involvement of miRNAs in the pathophysiology of both T2D and cancer, trying to identify the shared miRNA signature and pathways able to explain the strong correlation between the two conditions, as well as to envision new common pharmacological approaches.

miR-375 suppresses the growth and metastasis of esophageal squamous cell carcinoma by targeting PRDX1

BACKGROUND

Esophageal cancer (EC) is one of the most lethal cancers. Esophageal squamous cell carcinoma (ESCC) is the most common histological subtype in Asian people. Diverse microRNAs, such as miR-375, have been confirmed to be involved in the process of tumorigenesis and metastasis. However, the underlying mechanism through which miR-375 acts in ESCC patients remains unknown.

METHODS

We used The Cancer Genome Atlas (TCGA) database to analyze the association between miR-375 and the survival rate in patients with esophageal squamous cell carcinoma. Real Time quantitative PCR (RT-qPCR) analysis was performed to evaluate the level of miR-375 in EC tissues and cells. A luciferase reporter assay was used to confirm the target gene of miR-375. A colony formation assay as well as flow cytometric and transwell invasion experiments were employed to examine the effects of miR-375 and peroxiredoxin 1 (PRDX1) on ESCC cells. A tumor xenograft mouse model was then used to investigate the role of miR-375 on tumor growth in vivo. Moreover, we performed rescue experiments to evaluate the effect of PRDX1 on ESCC progression.

RESULTS

miR-375 expression was significantly downregulated in both ESCC clinical tissues and serum, and the reduction of miR-375 was remarkably linked to a poor prognosis in ESCC. Further investigation illustrated that aberrant expression of miR-375 dampened the growth and infiltration of ESCC cells both in vitro and in vivo. Bioinformatics and luciferase reporter analysis verified that the transcript of PRDX1 is a direct target of miR-375 and its expression in ESCC cells was found to be inversely modulated by miR-375. Moreover, the tumor formation experiment in nude mice confirmed that miR-375 can effectively dampen tumor growth in xenograft tumor mice models. Notably, over-expression of PRDX1 effectively counteracted the tumor-suppressing capabilities of miR-375.

CONCLUSIONS

We demonstrated the antitumor effect of miR-375 on ESCC by targeting PRDX1 both in vitro and in vivo.

Role of miRNA-495 and NRXN-1 and CNTN-1 mRNA Expression and Its Prognostic Importance in Breast Cancer Patients

Breast cancer is a heterogeneous disease in which genetic factors are involved in disease worsening and higher mortality. Epidemiological and clinical research revealed that breast cancer incidence continues to rise. 100 histopathologically confirmed untreated newly diagnosed cases of invasive ductal carcinoma (IDC) of breast and 100 healthy subjects were involved and blood samples were collected in non-EDTA plain vials. Serum was separated by centrifugation, total RNA was extracted from serum, and cDNA synthesis was done to study the miRNA-495 and neurexin-1 (NRXN-1) and contactin 1 (CNTN-1) mRNA expression by QRT-PCR. The expression levels of miRNA-495, NRXN-1, and CNTN-1 were expressed in fold change. The present study observed decreased relative miRNA-495 expression (0.07-fold) while an increase in NRXN-1 (11.61-fold) and CNTN-1 (4.92-fold) was observed among breast cancer patients compared to healthy controls. A significant difference was observed in miRNA-495 expression with menopausal status (p=0.0001) and TNM stages (p=0.02). It was observed that NRXN-1 expression was significantly associated with menopausal status (p=0.03), lymph node involvement (p < 0.0001), estrogen receptor (ER) status (p=0.03), progesterone receptor (PR) status (p=0.005), TNM stages (p < 0.0001), and distant metastases (p < 0.0001). CNTN-1 expression was also found to be associated with lymph node involvement (p=0.01), PR status (p=0.03), HER2 status (p=0.04), TNM stages (p < 0.0001), and distant metastases (p < 0.0001). ROC suggested that NRXN-1 and CNTN-1 could be the important predictive marker for disease advancement and distant organ metastases. The study concluded that the decreased expression of miR-495 observed in breast cancer patients showed a negative correlation with NRXN-1 while the increased expression of NRXN-1 and CNTN-1 was linked with disease advancement and distant metastases and could be the important predictive marker for breast cancer patients.