Genetic polymorphisms in cyclin D1 are associated with risk of renal cell cancer in the Chinese population

The expression of c-MYC, Cyclin D1 and Ki-67/MIB-1 in benign and malignant thyroid tissues: is there any diagnostic value?

AIM

To investigate the immunohistochemical (IHC) expression and the diagnostic value of c-MYC, Cyclin D1, and Ki-67∕MIB-1 in follicular adenomas (FAs), follicular carcinomas (FCs), and anaplastic carcinomas (ACs) of the thyroid gland, as well as in their corresponding adjacent, non-neoplastic thyroid tissue (NNTT).

MATERIALS AND METHODS

We conducted a retrospective study of patients who were pathologically diagnosed with FA, FC, or AC after total thyroidectomy. Tissue microarrays with cores taken from neoplastic and adjacent NNTT were constructed. Immunohistochemistry for anti-c-MYC, anti-Cyclin D1, and anti-Ki-67∕MIB-1 antibodies was performed, and the positivity was evaluated.

RESULTS

Twenty-eight specimens were included. Nuclear c-MYC positivity was observed in 4∕11 FCs, and 3∕4 ACs, whereas cytoplasmic c-MYC positivity was found in 16∕24 NNTTs. Globally, there were statistically significant differences between neoplasms and NNTTs, with higher nuclear c-MYC and Cyclin D1 expression observed in neoplasms (p=0.017 and p=0.001, respectively). In contrast, cytoplasmic positivity was seen solely in NNTTs (p=0.001). Cyclin D1 positivity was noted in 11∕13 FAs, 7∕11 FCs, 2∕4 ATCs, and only in one NNTT. A statistically significant correlation was found between MIB1 and c-MYC nuclear positivity (p=0.040).

CONCLUSIONS

Our findings exhibit a clear difference in the IHC expression of c-MYC and Cyclin D1 between different types of thyroid tumors, as well as between the neoplastic and NNTT. Nuclear c-MYC positivity excludes the benign nature of a thyroid lesion, in contrast to cytoplasmic positivity, which demonstrates normal or hyperplastic nature.

Association of CCND1 (c.723G > A, rs9344) variant with elevated risk of breast carcinoma: a retrospective case-control study

BACKGROUND

The prevalence rate of breast carcinoma (BC) among multiple ethnic populations required more explanations to understand the pathogenesis mechanisms for the development of this type of cancer. The principal purpose of this work is to validate the correlation of the CCND1 (c.723G > A; rs9344) variant with an increased risk of breast carcinoma.

METHODS

This retrospective case-controlled study was designed appertaining to 200 women including 100 BC patients and 100 unrelated cancer-free controls. The amplification of genomic DNA was genotyped utilizing the PCR-RFLP technique.

RESULTS

The frequencies of the CCND1 (c.723G > A; rs9344) variant revealed a significant association with increased risk of breast carcinoma under different genetic models including allelic (OR = 2.84, P-value < 0.001), recessive (OR = 4.83, P-value < 0.001), and dominant (OR = 3.19, P-value < 0.001) models.

CONCLUSIONS

Our findings concluded that the genetic biomarker of the CCND1 (c.723G > A; rs9344) variant is correlated with an elevated risk of breast carcinoma among Egyptian women.

Genetic and expression variations of cell cycle pathway genes in brain tumor patients

The present study was designed to determine the association between the genetic polymorphisms/expression variations of RB1 and CCND1 genes and brain tumor risk. For this purpose, 250 blood samples of brain tumor patients along with 250 controls (cohort I) and 96 brain tumor tissues (cohort II) with adjacent control section were collected. Mutation analysis of RB1 (rs137853294, rs121913300) and CCND1 (rs614367, rs498136) genes was performed using ARMS-PCR followed by sequencing, and expression analysis was performed using real-time PCR and immunohistochemistry. The results showed homozygous mutant genotype of RB1 gene polymorphism, rs121913300 (P=0.003) and CCND1 gene polymorphism rs614367 (P=0.01) were associated significantly with brain tumor risk. Moreover, significant down-regulation of RB1 (P=0.005) and up-regulation of CCND1 (P=0.0001) gene was observed in brain tumor sections vs controls. Spearman correlation showed significant negative correlation between RB1 vs proliferation marker, Ki-67 (r = -0.291*, P<0.05) in brain tumors. Expression levels of selected genes were also assessed at protein level using immunohistochemical analysis (IHC) and signification down-regulation of RB1 (P=0.0001) and up-regulation of CCND1 (P=0.0001) was observed in brain tumor compared with control sections. In conclusion, it is suggested that polymorphisms/expression variations of RB1 and CCND1 genes may be associated with increased risk of brain tumor.

Bioinformatic analysis reveals MIR502 as a potential tumour suppressor in ovarian cancer

BACKGROUND

Ovarian cancer (OC) is a major cause of death among women due to the lack of early screening methods and its complex pathological progression. Increasing evidence has indicated that microRNAs regulate gene expression in tumours by interacting with mRNAs. Although the research regarding OC and microRNAs is extensive, the vital role of MIR502 in OC remains unclear.

METHODS

We integrated two microRNA expression arrays from GEO to identify differentially expressed genes. The Kaplan-Meier method was used to screen for miRNAs that had an influence on survival outcome. Upstream regulators of MIR502 were predicted by JASPAR and verified by ChIP-seq data. The LinkedOmics database was used to study genes that were correlated with MIR502. Gene Set Enrichment Analysis (GSEA) was conducted for functional annotation with GO and KEGG pathway enrichment analyses by using the open access WebGestalt tool. We constructed a PPI network by using STRING to further explore the core proteins.

RESULTS

We found that the expression level of MIR502 was significantly downregulated in OC, which was related to poor overall survival. NRF1, as an upstream regulator of MIR502, was predicted by JASPAR and verified by ChIP-seq data. In addition, anti-apoptosis and pro-proliferation genes in the Hippo signalling pathway, including CCND1, MYC, FGF1 and GLI2, were negatively regulated by MIR502, as shown in the GO and KEGG pathway enrichment results. The PPI network further demonstrated that CCND1 and MYCN were at core positions in the development of ovarian cancer.

CONCLUSIONS

MIR502, which is regulated by NRF1, acts as a tumour suppressor gene to accelerate apoptosis and suppress proliferation by targeting the Hippo signalling pathway in ovarian cancer.

Downregulation of miR‑193a‑3p via targeting cyclin D1 in thyroid cancer

Thyroid cancer (TC) is a frequently occurring malignant tumor with a rising steadily incidence. microRNA (miRNA/miR)‑193a‑3p is an miRNA that is associated with tumors, playing a crucial role in the genesis and progression of various cancers. However, the expression levels of miR‑193a‑3p and its molecular mechanisms in TC remain to be elucidated. The present study aimed to probe the expression of miR‑193a‑3p and its clinical significance in TC, including its underlying molecular mechanisms. Microarray and RNA sequencing data gathered from three major databases, specifically Gene Expression Omnibus (GEO), ArrayExpress and The Cancer Genome Atlas (TCGA) databases, and the relevant data from the literature were used to examine miR‑193a‑3p expression. Meta‑analysis was also conducted to evaluate the association between clinicopathological parameters and miR‑193a‑3p in 510 TC and 59 normal samples from the TCGA database. miRWalk 3.0, and the TCGA and GEO databases were used to predict the candidate target genes of miR‑193a‑3p. Gene Ontology, Kyoto Encyclopedia of Genes and Genomes and protein‑protein interaction network enrichment analyses were conducted by using the predicted candidate target genes to investigate the underlying carcinogenic mechanisms. A dual luciferase assay was performed to validate the targeting regulatory association between the most important hub gene cyclin D1 (CCND1) and miR‑193a‑3p. miR‑193a‑3p expression was considerably downregulated in TC compared with in the non‑cancer controls (P<0.001). The area under the curve of the summary receiver operating characteristic was 0.80. Downregulation of miR‑193a‑3p was also significantly associated with age, sex and metastasis (P=0.020, 0.044 and 0.048, respectively). Bioinformatics analysis indicated that a low miR‑193a‑3p expression may augment CCND1 expression to affect the biological processes of TC. In addition, CCND1, as a straightforward target, was validated through a dual luciferase assay. miR‑193a‑3p and CCND1 may serve as prognostic biomarkers of TC. Finally, miR‑193a‑3p may possess a crucial role in the genesis and progression of TC by altering the CCND1 expression.

MicroRNA‑628‑5p inhibits cell proliferation and induces apoptosis in colorectal cancer through downregulating CCND1 expression levels

MicroRNA (miR)-628-5p serves as an antitumor gene in a variety of cancers; however, the role of miR-628-5p in colorectal cancer remains largely unclear. The purpose of this study was to investigate the role and mechanism of miR-628-5p in colorectal cancer. Reverse transcription-quantitative PCR (RT-qPCR), colony formation assays and flow cytometric analysis were used to determine the expression levels of miR-628-5p in colorectal cancer tissues and cell lines, and the proliferative ability of colorectal cancer cells. TargetScan version 7.2 and dual-luciferase reporter assay were performed to predict and confirm miR-628-5p target genes. The expression levels of cyclin D1 (CCND1) and related genes were determined using RT-qPCR or/and western blotting analysis. miR-628-5p mimics and CCND1 plasmids were used to overexpress miR-628-5p and CCND1; it was demonstrated that the expression levels of miR-628-5p were significantly downregulated in colorectal cancer tissues and cell lines. miR-628-5p mimic-transfected cells inhibited the proliferation and induced apoptosis of HT-29 cells. CCND1, a downstream effector of miR-628-5p, promoted the proliferation and suppressed apoptosis of HT-29 cells, and the effects were reversed by miR-628-5p mimics. In conclusion, the present study suggested that colorectal cancer progression may be regulated through the miR-628-5p/CCND1 axis, and miR-628-5p could be used as a potential diagnostic and prognostic biomarker for colorectal cancer.

MicroRNA-466 inhibits osteosarcoma cell proliferation and induces apoptosis by targeting CCND1

Emerging pieces of evidence indicate that microRNA-466 (miR-466) serves as a tumor suppressor in several human tumors, including colorectal cancer and prostate cancer. However, whether miR-466 is involved in osteosarcoma (OS) progression remains largely unknown. The present study demonstrated that miR-466 was significantly downregulated in OS tissues and cell lines. Furthermore, it was revealed that the expression of miR-466 was negatively correlated with OS severity. Moreover, low miR-466 expression in patients with OS predicted poor prognosis. Through functional experiments, miR-466 overexpression significantly inhibited the proliferation and cell cycle of OS cells while inducing cellular apoptosis. In terms of mechanism, it was revealed that CCND1 was a target of miR-466 in OS cells. miR-466 overexpression suppressed CCND1 expression in OS cells. A reverse association was observed between the expression levels of miR-466 and CCND1 in OS tissues. Furthermore, CCND1 restoration in OS cells significantly rescued the effects of miR-466 on cellular proliferation and apoptosis. Overall, the results of the present study demonstrated that miR-466 suppressed OS progression by targeting CCND1, suggesting that miR-466 may be a promising biomarker and therapeutic target for OS prognosis and treatment.