Research progresses in roles of LncRNA and its relationships with breast cancer

Some progresses have been made in research of long non-coding RNA (hereunder referred to as LncRNA) related to breast cancer. Lots of data about LncRNA transcription concerning breast cancer have been obtained from large-scale omics research (e.g. transcriptomes and chips). Some LncRNAs would become indices for detecting breast cancer and judging its development and prognosis. LncRNAs may affect genesis and development of breast cancer in multiple ways. Perhaps they could develop into potential targets for treating breast cancer if they are carcinogenic. Like those from other studies of breast cancer, many data gained from omics research remain to be validated by much experimental work. For instance, it is still necessary to demonstrate reliability of LncRNAs as indices for diagnosing breast cancer and judging its prognosis (particularly for various subtypes of breast cancer), effectiveness and feasibility of these genes for treating breast cancer as targets. In this paper, recent years’ literatures about LncRNAs which are related to breast cancer are summarized and sorted out to review the research progresses in relationships between LncRNAs and breast cancer.

Meta-analysis of the Correlation Between Schizophrenia and Breast Cancer

PURPOSE

To determine the correlation between schizophrenia and breast cancer (BC).

METHODS

We searched relevant articles indexed in the PubMed, Embase, and Cochrane Library databases; managed the data in Endnote X7 software; evaluated literature quality by Newcastle-Ottawa quality evaluation criteria; designed tables; and extracted relevant data. The main outcome measure was BC incidence. Effect values were risk ratio and 95% confidence intervals. We used Stata 13.1 software to perform the meta-analysis, choosing a corresponding combination model according to heterogeneity test results and carrying out subgroup analyses in order to better understand the stability of results through sensitivity analysis.

RESULTS

On the basis of 15 studies that assessed patients in different geographic regions, meta-analysis results showed that BC incidence between the exposure group (patients with schizophrenia) and the control group (nonschizophrenia population or general population) had statistical difference (risk ratio = 1.18; 95% confidence interval, 1.05, 1.32), thus showing that BC incidence in patients with schizophrenia is higher than in the nonschizophrenia or general population. Subgroup analysis indicated that gender and geographic region may be sources of the assessed studies' heterogeneity.

CONCLUSION

The incidence of schizophrenia is positively correlated with BC, and the incidence of BC in patients with schizophrenia is increased to a certain degree. Because of the effects of potential and publication bias, this conclusion needs more high-quality studies to increase the strength of evidence.

Roles of MALAT1 in development and migration of triple negative and Her-2 positive breast cancer

Background

As a type of new targets for prognosis of malignancies, long non-coding RNA MALAT1 (metastasis-associated lung adenocarcinoma transcription 1) is associated with proliferation and metastatic abilities of several malignancies. However, its relations to development and migration of triple negative and human epidermal growth factor receptor 2 (Her-2) positive breast cancers haven't been reported.

Objectives

In this paper, we aimed to discuss how MALAT1 is connected with and affects proliferation and invasion abilities of cells in Her-2 positive and triple-negative breast cancers (TNBC).

Methods

The expression of MALAT1 in clinical samples with TNBC and Her-2 positive breast cancers was tested by qRT-PCR. The statistical analysis was performed to unveil the potential relationships between the expression of MALAT1 and prognostic factors of breast cancer such as OS (overall survival), RFS (relapse-free survival), number of metastatic lymph nodes and pTNM staging in patients with TNBC or Her-2 positive breast cancer. MALAT1 and XBP1 were knockdown respectively in Her-2 positive cell line MDA-MB-231, and MALAT1 and Her-2 were knockdown respectively in TNBC cell line MDA-MD-435 using siRNA. The alterations of expressions of MALAT1 and related genes were detected by qRT-PCR in two breast cancer cell lines. The changes of proliferation abilities in two cell lines were observed using CCK8 assays. Furthermore, transwell assays were performed to detect changes to invasion abilities of the cells.

Results

The expression of MALAT1 in triple negative and Her-2 positive breast cancers was positively correlated to the number of metastatic lymph nodes in patients with breast cancer. MALAT1 promotes proliferation and invasion abilities of breast cancer cells through XBP1 (X-box binding protein 1)-HIF (hypoxia-inducible factor)-1α pathway in MDA-MB-231 and through Her-2 pathway in MDA-MD-435. Moreover, MALAT1 could possibly be involved in regulation of MYC gene and CD47 (an immune checkpoint gene) in both cell lines.

Conclusions

Our study suggested that MALAT1 is a core signaling molecule for promoting development and migration of triple negative and Her-2 positive breast cancers. It would be employed as common markers for prognosis of the two types of breast cancer mentioned above and potential targets for treating them.