MAD2 Combined with Mitotic Spindle Apparatus (MSA) and Anticentromere Antibody (ACA) for Diagnosis of Small Cell Lung Cancer (SCLC).

BACKGROUND MAD2 is the gene controlling mitosis. Many studies have assessed MAD2 in various types of carcinoma. Antinuclear mitotic spindle apparatus antibody (MSA) and anticentromere antibody (ACA) are related mitotic antibodies, playing roles in autoimmune diseases and carcinomas, but the expression of MAD2, MSA, and ACA in SCLC is unclear. MATERIAL AND METHODS We enrolled 70 SCLC patients, 72 non-small cell lung cancer (NSCLC) patients, and 65 pulmonary nodule (PN) patients. MAD2 expression was measured through agarose electrophoresis and qt-PCR. Antinuclear mitotic spindle apparatus antibody (MSA) and anticentromere antibody (ACA) were detected by indirect immunofluorescence (IIF). RESULTS MAD2 was found both in SCLC and NSCLC. Interestingly, there was a significant difference found between SCLC and NSCLC using qt-PCR (P<0.05). The area under the ROC curve of MAD2 expression was 0.799, with medium diagnostic value. MAD2 expression was related to age, lymphatic metastasis, and survival time, but not with sex. The positivity for MSA and ACA by IIF assay were 37.20% and 34.00%, respectively, in the SCLC group, which were higher than in the NSCLC and pulmonary nodule groups (P<0.05). The kappa values of MSA and ACA with MAD2 expression were 0.73 and 0.65, respectively, with moderate consistency. Combining MAD2 with MSA and ACA enhanced the sensitivity and specificity for diagnosing SCLC. CONCLUSIONS MAD2 expression was found to be involved in carcinogenesis and prognosis of SCLC. The combination of MAD2 with MSA and ACA is useful for early diagnosis and shows promise in treatment of SCLC.

BRCA1 and MAD2 Are Coexpressed and Are Prognostic Indicators in Tubo-ovarian High-Grade Serous Carcinoma.

OBJECTIVES: The aim of this study was to investigate the relationship between BRCA1 and mitotic arrest deficiency protein 2 (MAD2) protein expression, as determined by immunohistochemistry, and clinical outcomes in epithelial ovarian carcinoma (EOC). METHODS: A tissue microarray consisting of 94 formalin-fixed paraffin-embedded EOC with fully matched clinicopathological data were immunohistochemically stained with anti-BRCA1 and anti-MAD2 antibodies. The cores were scored in a semiquantitative manner evaluating nuclear staining intensity and extent. Coexpression of BRCA1 and MAD2 was evaluated, and patient survival analyses were undertaken. RESULTS: Coexpression of BRCA1 and MAD2 was assessed in 94 EOC samples, and survival analysis was performed on 65 high-grade serous carcinomas (HGSCs). There was a significant positive correlation between BRCA1 and MAD2 expression in this patient cohort (P < 0.0001). Both low BRCA1 and low MAD2 are independently associated with overall survival because of HGSC. Low coexpression of BRCA1 and MAD2 was also significantly associated with overall survival and was driven by BRCA1 expression. CONCLUSION: BRCA1 and MAD2 expressions are strongly correlated in EOC, but BRCA1 expression remains the stronger prognostic factor in HGSC.

Knockdown of REV7 Inhibits Breast Cancer Cell Migration and Invasion.

REV7 (also known as MAD2L2) is a multifunctional protein involved in DNA damage tolerance, cell cycle regulation, gene expression, and carcinogenesis. Although its expression is reportedly associated with poor prognosis in several kinds of human cancers, the significance of REV7 expression in breast malignancies is unclear. In this study, REV7 was found to be increased in breast cancer. We found that knockdown of REV7 inhibited the migration, invasion, and epithelial-mesenchymal transition (EMT) of breast cancer cells. Meanwhile, overexpression of REV7 promoted the migration, invasion, and EMT of breast cancer cells. As shown by Western blot, knockdown of REV7 can promote TGF-ß1 expression. Western blot analysis indicated that TGF-ß1 may play a role as a downstream factor of REV7. Moreover, interference of TGF-ß1 can also inhibit the cell's ability for migration, invasion, and EMT, as well as in a cell line whose REV7 is overexpressed. Taken together, these results contributed to a recognition of the oncogene functions of REV7 in breast cancer cells and provided a novel direction to treat breast cancer.

Mad2 overexpression is associated with high cell proliferation and reduced disease-free survival in primary gastrointestinal diffuse large B-cell lymphoma.

OBJECTIVES: Primary gastrointestinal diffuse large B-cell lymphoma (PGI-DLBCL) is a rare hematological malignancy with limited results on carcinogenesis and clinical characteristics. The aims of the current study were to examine mitotic arrest deficiency protein 2 (Mad2) expressions in PGI-DLBCL, and assess its association with Ki-67 expression, Helicobacter pylori (H. pylori) infection, BCL-6 gene rearrangement, and clinicopathological variables. METHODS: Cancer tissues from 38 PGI-DLBCL patients were examined for Mad2, Ki-67, and H. pylori expression by immunohistochemistry, using normal gastrointestinal tissues and nodal DLBCL as controls. BCL-6 gene translocation was analyzed by fluorescence in situ hybridization (FISH), and Mad2 expression status was evaluated along with clinicopathological characteristics. RESULTS: Mad2 expression was increased in PGI-DLBCL patients when compared with controls. The expression of Mad2 was 51.55 ± 22.88% in PGI-DLBCL, which was higher than reactive lymph node (28.77 ± 10.89%) and lymphoid nodule in normal gastrointestinal tissue (26.41 ± 11.30%) (P = 0.002), while it was comparable to nodal DLBCL (57.23 ± 20.79%) (P = 0.358). Mad2 overexpression had a positive correlation with Ki-67 proliferation index (r = 0.55, P = 0.01) in PGI-DLBCL, and patients with BCL-6 gene rearrangement had lower Mad2 expression (P = 0.032) than patients with intact BCL-6, while no relation was found between Mad2 expression and H. pylori infection. PGI-DLBCL patients with higher Mad2 expression had lower estimated disease-free survival (DFS) (17.10% vs. 53.00%) (P = 0.049). However, no correlation was found between Mad2 expression levels and overall survival (OS) (P = 0.443). CONCLUSIONS: Aberrant Mad2 expression was associated with cell proliferation and genetic instability, which may contribute to the carcinogenesis of PGI-DLBCL. Mad2 overexpression indicated a poor DFS and may be a potential biomarker for estimating prognosis for PGI-DLBCL patients.

Visceral obesity stimulates anaphase bridge formation and spindle assembly checkpoint dysregulation in radioresistant oesophageal adenocarcinoma.

PURPOSE: Oesophageal adenocarcinoma is an exemplar model of obesity-associated cancer. Locally advanced disease is treated with neoadjuvant chemoradiotherapy, and survival rates are highest in patients demonstrating a pathological response following neoadjuvant therapy. Given that 55 % of oesophageal adenocarcinoma patients are obese, uncovering the effect of adipose tissue on radioresponse is clinically relevant. This study investigates if adipose tissue activates genomic instability events in radioresponsive (OE33P) and radioresistant (OE33R) oesophageal cancer cell lines and tumour samples. METHODS: OE33R and OE33P were cultured with adipose-conditioned media derived from oesophageal adenocarcinoma patients (n = 10). Anaphase bridges, a marker of genomic instability, were enumerated in both cell lines following treatment with adipose media, and normalised to cell number. Genomic instability is regulated by the spindle assembly complex. Expression of two spindle assembly complex genes (MAD2L2, BUB1B) was assessed using qPCR, and validated in patient tumour specimens from viscerally obese (n = 46) and nonobese patients (n = 41). RESULTS: Adipose-conditioned media increased anaphase bridging in OE33R (p < 0.0001), with a threefold increase in OE33R compared to OE33P (p < 0.01). Levels of anaphase bridges in OE33R cells correlated with visceral obesity status as measured by waist circumference (R = 0.709, p = 0.03) and visceral fat area (R = 0.794, p = 0.006). Adipose tissue altered expression of MAD2L2 in vitro. In vivo, MAD2L2 expression was higher in viscerally obese oesophageal adenocarcinoma patients compared with nonobese patients (p < 0.05). CONCLUSIONS: Anaphase bridge levels are influenced by obesity and radiosensitivity status in oesophageal adenocarcinoma. Furthermore, visceral adipose-conditioned media stimulates dysregulation of the spindle assembly complex in oesophageal adenocarcinoma patients.

MAD2 expression in oral squamous cell carcinoma and its relationship to tumor grade and proliferation.

BACKGROUND: Defects in the cell-cycle surveillance mechanism, called the spindle checkpoint, might contribute to the chromosomal instability observed in human cancers, including oral squamous cell carcinoma. MAD2 and BUBR1 are key components of the spindle checkpoint, whose role in oral carcinogenesis and clinical relevance still need to be elucidated. MATERIALS AND METHODS: We analyzed the expression of MAD2 in 49 cases of oral squamous cell carcinoma by immunohistochemistry and compared the findings with clinicopathological parameters, proliferative activity, BUBR1 expression and DNA ploidy. RESULTS: MAD2 was over-expressed in 18 (36.7%) cases. Tumors with over-expression of MAD2 were associated with the progression of histological grade from well to poor differentiation (p<0.001), the extent of lymph nodes involvement (PN) (p=0.0339) and Ki-67 labeling index (p<0.001). CONCLUSION: MAD2 may be involved in oral carcinogenesis and may represent an important prognostic factor associated with a more malignant phenotype of oral squamous cell carcinoma.

The transcription factor TFII-I promotes DNA translesion synthesis and genomic stability.

Translesion synthesis (TLS) enables DNA replication through damaged bases, increases cellular DNA damage tolerance, and maintains genomic stability. The sliding clamp PCNA and the adaptor polymerase Rev1 coordinate polymerase switching during TLS. The polymerases Pol η, ι, and κ insert nucleotides opposite damaged bases. Pol ζ, consisting of the catalytic subunit Rev3 and the regulatory subunit Rev7, then extends DNA synthesis past the lesion. Here, we show that Rev7 binds to the transcription factor TFII-I in human cells. TFII-I is required for TLS and DNA damage tolerance. The TLS function of TFII-I appears to be independent of its role in transcription, but requires homodimerization and binding to PCNA. We propose that TFII-I bridges PCNA and Pol ζ to promote TLS. Our findings extend the general principle of component sharing among divergent nuclear processes and implicate TLS deficiency as a possible contributing factor in Williams-Beuren syndrome.

Expression of budding uninhibited by benzimidazoles-1 and mitotic arrest deficient-2 in endometrial carcinoma and its significance.

OBJECTIVE: The aim of this study was to explore the expression of budding uninhibited by benzimidazoles-1 (Bub1) and mitotic arrest deficient-2 (Mad2) in endometrial carcinoma and its significance. MATERIALS AND METHODS: The expression of Bub 1 and Mad2 in 30 human normal endometrial tissues (group A), 30 complexly-hyperplastic endometrial tissues (group B), and 63 endometrial carcinoma tissues (group C) was observed using immunohistochemistry (the streptavidin-peroxidase method). RESULTS: The positive expression rates of Bub1 in groups A, B, and C were 86.67%, 56.67%, and 28.57%, respectively. The positive rate of Bub1 protein was correlated with the differentiation degree and clinical stage of endometrial carcinoma (p < 0.05) other than lymph node metastasis (p > 0.05): A higher differentiation degree and a more advanced stage of endometrial carcinoma indicated a higher positive rate of Bub1 protein. The positive rates of Mad2 protein in groups A, B, and C were 23.33%, 56.67%, and 85.71%, respectively. The positive rate of Mad2 protein was correlated with the differentiation degree of endometrial carcinoma (p < 0.05) other than its clinical stage and lymph node metastasis (p > 0.05): A lower differentiation degree indicated a higher positive rate of Mad2 protein. Bub1 and Mad2 proteins were negatively correlated in the endometrial carcinoma tissues (r = - 0.719, p < 0.001). CONCLUSION: Bub1 and Mad2 proteins interact with each other. They may play an important role in the initiation and development of endometrial carcinoma.