Her-2 expression regulated by downregulation of miR-9 and which affects chemotherapeutic effect in breast cancer

TMEM16A ion channel: A novel target for cancer treatment

Cancer draws attention owing to the high morbidity and mortality. It is urgent to develop safe and effective cancer therapeutics. The calcium-activated chloride channel TMEM16A is widely distributed in various tissues and regulates physiological functions. TMEM16A is abnormally expressed in several cancers and associate with tumorigenesis, metastasis, and prognosis. Knockdown or inhibition of TMEM16A in cancer cells significantly inhibits cancer development. Therefore, TMEM16A is considered as a biomarker and therapeutic target for some cancers. This work reviews the cancers associated with TMEM16A. Then, the molecular mechanism of TMEM16A overexpression in cancer was analyzed, and the possible signal transduction mechanism of TMEM16A regulating cancer development was summarized. Finally, TMEM16A inhibitors with anticancer effect and their anticancer mechanism were concluded. We hope to provide new ideas for pharmacological studies on TMEM16A in cancer.

Smart Programmable Scalable Dual-Mode Diagnostic Logic Nanoflare Strategy for Dual-Tumor Marker Detection

Compared with the single-marker detection scheme, the detection of multiple targets in the complex cell and biological environment can obtain more reliable detection results. Herein, we detected miRNA-21 and APE1 in two modes, AND and OR, respectively, based on gold nanoflares and simple logic components. In both modes, DNAzyme and APE1 can get rich fluorescence recovery results by breaking the DNA strands from the gold nanorods (AuNRs) and unquenching under different conditions. In vivo and in vitro experiments suggest that both nanoflares exhibit excellent biocompatibility and make efficient and sensitive judgments on the two targets. This strategy emphasizes the reuse nature of enzymes, and a small amount of target can generate a large amount of fluorescent signal in the logic device, which greatly reduces the detection limit when monitoring low-abundance targets. Since the short-stranded DNA component of the detection device is simple in composition and easy to program its probe sequence, it can be expanded into a detection system for the detection of other sets of related markers, which increases its potential for clinical application.

Overview of MicroRNA Expression in Predicting Response to Neoadjuvant Therapies in Human Epidermal Growth Receptor-2 Enriched Breast Cancer - A Systematic Review

Purpose:

Increased appreciation of the human epidermal growth factor receptor-2 (HER2/neu) signalling pathway has led to the development of targeted therapeutic agents used in conjunction with chemotherapy to improve outcomes for HER2 overexpressing (HER2+) breast cancer. For neoadjuvant therapy, response rates can be unpredictable – novel biomarkers predicting effectiveness are required to enhance oncological outcomes for these patients, and microRNA may prove effective. Our objective was to identify microRNA (miRNA) expression patterns predictive of response to neoadjuvant chemotherapy (NAC) and/or anti-HER2 targeted therapies in patients being treated for early-stage HER2+ breast cancer.

Methods:

A search was performed of the PUBMED, SCOPUS, Web of Science, and EMBASE in accordance to Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines.

Results:

Overall, 15 studies including 1335 patients were included. These studies highlighted an expression profile of 73 miRNA and their ability to predict tumour response to neoadjuvant therapies was correlated. Results from 11 studies were in relation to circulatory miRNA and 4 studies included data from tumour tissue. Overall, upregulation and downregulation of 41 miRNA and 29 miRNA, respectively, predicted differential response to neoadjuvant therapy. Expression levels of 3 miRNA (miR-21, miR-210, and miR-376c-3p) were inconclusive in predicting therapeutic response, while ‘aberrant’ expression of circulating miR-199a predicted pathological complete response (pCR) to NAC.

Conclusions:

This systematic review outlines expression patterns of a number of miRNA which correlate with response to NAC and/or anti-HER2 therapies. Future translational research evaluating predictive biomarkers of primary response to neoadjuvant therapy in HER2+ breast cancer may consider these results.

Long non-coding RNA SNHG6 increases JAK2 expression by targeting the miR-181 family to promote colorectal cancer cell proliferation

BACKGROUND

Long non-coding RNA (lncRNA) small nucleolar RNA host gene 6 (SNHG6) exerts a regulatory role in cancer biology, although its detailed functions and mechanisms in colorectal cancer (CRC) still remain unclear.

METHODS

A quantitative reverse transcriptase-polymerase chain reaction was implemented to investigate the expression of SNHG6, miR-181 family and Janus kinase 2 (JAK2) in CRC tissues and cell lines. The proliferation of CRC cells was detected by a cell counting kit-8 assay, and the apoptosis of CRC cells was determined by flow cytometry analysis. The interaction of the miR-181 family with SNHG6 or with the 3'-untranslated region of JAK2 was validated by the luciferase reporter gene method. The effects of SNHG6 and the miR-181 family on JAK2 expression were analyzed by western blotting.

RESULTS

SNHG6 was significantly up-regulated in CRC samples. The knockdown of SNHG6 reduced the proliferation of CRC cells and promoted the apoptosis, whereas the over-expression of SNHG6 had the opposite effect. SNHG6 could bind with all the four members of the miR-181 family, and expression in miR-181 family members was significantly down-regulated in CRC samples. SNHG6 expression was negatively correlated with the miR-181 family member expression in CRC samples. Moreover, over-expressed SNHG6 significantly counteracted the inhibitory effect of miR-181 mimics on CRC cell proliferation, as well as the promoting effect on apoptosis. Furthermore, SNHG6 over-expression and knockdown can promote and inhibit JAK2 expression, respectively, and miR-181 family member function is opposite to that of SNHG6 by repressing JAK2.

CONCLUSIONS

SNHG6 can exert a cancer-promoting effect in CRC by targeting miR-181 family members and up-regulating JAK2.

miR‑204‑5p promotes apoptosis and inhibits migration of gastric cancer cells by targeting HER‑2

Gastric cancer is one of the most common types of cancer worldwide, with a high incidence and mortality rate. MicroRNAs (miRs) play an important role in tumorigenesis, cell proliferation, migration, apoptosis and metastasis of cancer. The present study aimed to investigate the role and potential mechanism of miR‑204‑5p in gastric cancer. The mRNA expression levels of miR‑204‑5p in gastric cancer were determined by reverse transcription‑quantitative PCR. Cell proliferation was determined using Cell Counting Kit‑8 and colony formation assays. Flow cytometry analysis was performed to detect the cell apoptosis rate. Wound healing and Transwell assays were carried out to determine the cell migration and invasion rates, respectively. A putative binding site of miR‑204‑5p in the 3' untranslated region of human epidermal growth factor receptor 2 (HER‑2) was predicted using a bioinformatics algorithm and confirmed using a dual‑luciferase reporter assay. miR‑204‑5p levels were downregulated in gastric cancer cells. Overexpression of miR‑204‑5p significantly inhibited cell proliferation and decreased cell colony formation. Additionally, miR‑204‑5p decreased the migration and invasion rates of gastric cancer cells. Furthermore, an increased apoptotic rate was detected following overexpression of miR‑204‑5p, along with increased expression levels of Bax and decreased expression levels of Bcl‑2. HER‑2 was a direct target of miR‑204‑5p, and inhibition of HER‑2 acted as a tumor suppressor by inhibiting cell proliferation, migration and invasion, and promoting cell apoptosis, which was reversed by the inhibition of miR‑204‑5p expression. These results suggested that miR‑204‑5p could exert its anti‑tumor function by inhibiting cell proliferation, migration and invasion, and promoting cell apoptosis via regulation of HER‑2, which may be a potential therapeutic target for gastric cancer.

Construction of differentially expressed Her-2 related lncRNA-mRNA-miRNA ceRNA network in Her-2 positive breast cancer

Background

Her-2 positive subtype breast cancer is characterized as Her-2 gene amplification with poor survival and increased invasiveness accounting for 20–30% of invasive infiltrated breast cancer. A lncRNA-miRNA-mRNA competing endogenous RNA (ceRNA) network is constructed to detect Her-2 specific RNAs in the development and progression of HER-2 positive breast cancer which may overcoming the anti-HER-2 therapy resistance of breast cancer cells.

Methods

One thousand one hundred and nine breast cancer samples obtained from The Cancer Genome Atlas (TCGA) database were classified into two cohorts including ER+/PR+ (n=461) and ER-/PR- breast cancer (n=152). Differently expressed mRNAs, lncRNAs and miRNAs were screened in ER+/PR+ and ER-/PR- breast cancer cohorts, respectively. lncRNA-miRNA interactions were preformed to predicted and verified by miRcode. miRNA-mRNA interactions were selected to predict targeted mRNAs of miRNAs by miRanda, Targetscan and miRTarBase.

Results

lncRNA-miRNA-mRNA ceRNA network was constructed by retained lncRNAs, miRNAs and mRNAs. Fifteen DEmiRNAs, 129 DElncRNAs and 269 DEmRNAs were retained in ER+/PR+ cohort after intersection with DEmiRNAs, DElncRNAs and DEmRNAs between breast cancer and normal tissues. Six hundred and ninety-three DEmRNAs, 25 DEmiRNAs and 364 DElncRNAs were retained in ER-/PR- cohort. ceRNA network in ER+/PR+ breast cancer cohort was constructed of the interactions of 4 DElncRNA–DEmiRNA pairs and 2 DEmiRNA–DEmRNA pairs included 4 DElncRNAs, 1 DEmiRNAs, and 2 DEmRNAs. ceRNA network in ER-/PR- breast cancer cohort was constructed of the interactions of 24 DElncRNA–DEmiRNA pairs and 1 DEmiRNA–DEmRNA pairs included 19 DElncRNAs, 4 DEmiRNAs, and 1 DEmRNA. MIR7-3HG- hsa-mir-204-NTRK2 axis was identified in both ER+/PR+ and ER-/PR- cohort in our study.

Conclusions

Based on the ceRNA hypothesis, a potential Her-2 related regulatory ceRNA networks are constructed which may provide novel insights into the mechanism underlying the biological processes of Her-2 positive breast cancer.

MicroRNA-9 and breast cancer

Breast cancer is the most common cancer in women worldwide and seriously impairs patients' physical and mental health. Its incidence has been predicted to rise further. Mounting evidence indicates that microRNAs (miRNAs) play key roles in tumorigenesis and development. It is worth noting that miR-9 exerts critical functions in the initiation and progression of breast cancer, and the present research displays opposite roles of miR-9 in breast cancer. This article mainly reviews the roles of miR-9 in breast cancer progression.

MicroRNA-9 exerts antitumor effects on hepatocellular carcinoma progression by targeting HMGA2

Accumulating evidence has demonstrated that the aberrant expression of microRNAs (miRs or miRNAs) may contribute to the initiation and progression of various types of human cancer and may also constitute biomarkers for cancer diagnosis and therapy. However, the specific function of miR‐9 in hepatocellular carcinoma (HCC) remains unclear, and the mechanisms that underlie HCC are incompletely understood. Here, we report that miR‐9 expression was significantly decreased in clinical tumor tissue samples, as well as in a cohort of HCC cell lines. In addition, it was demonstrated that overexpression of miR‐9 suppressed the proliferative and migratory capacity of HCC cells and impaired cell cycle progression. Furthermore, high mobility group AT‐hook 2 (HMGA2) was verified as a downstream target gene of miR‐9 using a luciferase reporter assay. Quantitative RT‐PCR and western blotting implicated HMGA2 in the miR‐9‐mediated reduction of HCC cell growth. In vivo, transfection with miR‐9 mimics down‐regulated the expression of HMGA2, thus leading to a dramatic reduction in tumor growth in a mouse xenograft model. These results suggest that miR‐9 may exert critical antitumor effects on HCC by directly targeting HMGA2, and the miR9/HMGA2 signaling pathway may be of use for the diagnosis and prognosis of patients with HCC.

Alkylating anticancer agents and their relations to microRNAs

Alkylating agents represent an important class of anticancer drugs. The occurrence and emergence of tumor resistance to the treatment with alkylating agents denotes a severe problem in the clinics. A detailed understanding of the mechanisms of activity of alkylating drugs is essential in order to overcome drug resistance. In particular, the role of non-coding microRNAs concerning alkylating drug activity and resistance in various cancers is highlighted in this review. Both synthetic and natural alkylating agents, which are approved for cancer therapy, are discussed concerning their interplay with microRNAs.

MicroRNA‑124 suppresses cell proliferation and invasion of triple negative breast cancer cells by targeting STAT3

MicroRNAs (miRNAs) are pivotal regulators of the progression of carcinogenesis and negatively regulate the expression of tumour-associated genes. Downregulation of miR-124 expression has been demonstrated in various human cancer tissues, wherein miR-124 serves as a tumour suppressor by targeting oncogenes. However, its function and underlying mechanism of action remain unclear in breast cancer. In the present study, the tissue-specific expression of miR-124 was detected in 10 paired triple-negative breast cancer and normal tissues, and its inhibitory effects on cell growth and invasion were evaluated in vitro and in vivo. Bioinformatics analysis identified signal transducer and activator of transcription 3 (STAT3), a well-known oncogene in breast cancer, as the potential target. Upregulation of miR-124 expression decreased STAT3 mRNA and protein levels in breast cancer cells and the relative luciferase activity. Rescue experiments revealed that the transfection of a STAT3 expression plasmid reversed the inhibitory effect of miR-124 on the proliferation and invasion of MDA-MB-468 cells. These data demonstrate that miR-124 serves vital roles in the suppression of triple-negative breast cancer via inhibition of cell proliferation and invasion through STAT3. These results highlight the potential role of miR-124 as a diagnostic or therapeutic target in patients with breast cancer.

Regulation of RAB22A by mir-193b inhibits breast cancer growth and metastasis mediated by exosomes

Breast cancer is one of the main types of cancer affecting the health of females worldwide. Despite improvements in therapeutic approaches, cancer patients succumb to the disease due to metastasis itself, rather than the primary tumor from which metastases arise, emphasizing the need for the better understanding of the biological bases that contribute to disease progression. RAB22A, a member of the proto-oncogene RAS family, plays an important role in the formation, trafficking and metabolism of exosomes, and is associated with the occurrence and development of multiple human cancers. In this study, we demonstrate that the upregulation of RAB22A is associated with breast cancer progression and lymph node metastasis. We identified a signature of RAB22A and miR-193b that exhibited a negative association in metastatic as opposed to the surrounding normal cells, and RAB22A was identified as the target gene of miR-193b. While RAB22A was found to regulate exosomes-mediated breast cancer cell proliferation, invasion and migration, these biological characteristics were diminished in the breast cancer cells in which the RAB22A gene was knocked down or in the cells in which the exosomes were dissolved by proteinase K/RNase treatment. On the whole, the findings of this study demonstrate the critical role that miR-193b plays in the regulation of RAB22A-mediated exosome function during cancer growth and metastasis, which may have significant implications on cancer therapy.

miRNA in a multiomic context for diagnosis, treatment monitoring and personalized management of metastatic breast cancer

Metastatic breast cancer is characterized by aggressive spreading to distant organs. Despite huge multilevel research, there are still several important challenges that have to be clarified in the management of this disease. Therefore, recent investigations have implemented a modern, multiomic approach with the aim of identifying specific biomarkers for not only early detection but also to predict treatment responses and metastatic spread. Specific attention is paid to short miRNAs, which regulate gene expression at the post-transcriptional level. Aberrant miRNA expression could initiate cancer development, cell proliferation, invasion, migration, metastatic spread or drug resistance. An miRNA signature is, therefore, believed to be a promising biomarker and prediction tool that could be utilized in all phases of carcinogenesis. This article offers comprehensive information about miRNA profiles useful for diagnostic and treatment purposes that may sufficiently advance breast cancer management and improve individual outcomes in the near future.

Hematopoietic stem cells from induced pluripotent stem cells - considering the role of microRNA as a cell differentiation regulator

Although hematopoietic stem cell (HSC) therapy for hematological diseases can lead to a good outcome from the clinical point of view, the limited number of ideal donors, the comorbidity of patients and the increasing number of elderly patients may limit the application of this therapy. HSCs can be generated from induced pluripotent stem cells (iPSCs), which requires the understanding of the bone marrow and liver niches components and function in vivo iPSCs have been extensively applied in several studies involving disease models, drug screening and cellular replacement therapies. However, the somatic reprogramming by transcription factors is a low-efficiency process. Moreover, the reprogramming process is also regulated by microRNAs (miRNAs), which modulate the expression of the transcription factors OCT-4 (also known as POU5F1), SOX-2, KLF-4 and MYC, leading somatic cells to a pluripotent state. In this Review, we present an overview of the challenges of cell reprogramming protocols with regard to HSC generation from iPSCs, and highlight the potential role of miRNAs in cell reprogramming and in the differentiation of induced pluripotent stem cells.