scholarly journals Deregulation of LIMD1–VHL–HIF-1α–VEGF pathway is associated with different stages of cervical cancer

2018 ◽  
Vol 475 (10) ◽  
pp. 1793-1806 ◽  
Author(s):  
Chandraditya Chakraborty ◽  
Sraboni Mitra ◽  
Anirban Roychowdhury ◽  
Sudip Samadder ◽  
Sankhadeep Dutta ◽  
...  

To understand the mechanism of cellular stress in basal–parabasal layers of normal cervical epithelium and during different stages of cervical carcinoma, we analyzed the alterations (expression/methylation/copy number variation/mutation) of HIF-1α and its associated genes LIMD1, VHL and VEGF in disease-free normal cervix (n = 9), adjacent normal cervix of tumors (n = 70), cervical intraepithelial neoplasia (CIN; n = 32), cancer of uterine cervix (CACX; n = 174) samples and two CACX cell lines. In basal–parabasal layers of normal cervical epithelium, LIMD1 showed high protein expression, while low protein expression of VHL was concordant with high expression of HIF-1α and VEGF irrespective of HPV-16 (human papillomavirus 16) infection. This was in concordance with the low promoter methylation of LIMD1 and high in VHL in the basal–parabasal layers of normal cervix. LIMD1 expression was significantly reduced while VHL expression was unchanged during different stages of cervical carcinoma. This was in concordance with their frequent methylation during different stages of this tumor. In different stages of cervical carcinoma, the expression pattern of HIF-1α and VEGF was high as seen in basal–parabasal layers and inversely correlated with the expression of LIMD1 and VHL. This was validated by demethylation experiments using 5-aza-2′-deoxycytidine in CACX cell lines. Additional deletion of LIMD1 and VHL in CIN/CACX provided an additional growth advantage during cervical carcinogenesis through reduced expression of genes and associated with poor prognosis of patients. Our data showed that overexpression of HIF-1α and its target gene VEGF in the basal–parabasal layers of normal cervix was due to frequent inactivation of VHL by its promoter methylation. This profile was maintained during different stages of cervical carcinoma with additional methylation/deletion of VHL and LIMD1.

2016 ◽  
Vol 473 (19) ◽  
pp. 3221-3236 ◽  
Author(s):  
Chandraditya Chakraborty ◽  
Anirban Roychowdhury ◽  
Sudip Samadder ◽  
Anup Roy ◽  
Ranajit Kumar Mandal ◽  
...  

To understand the molecular mechanism of RB1 phosphorylation in basal–parabasal layers of normal cervix and during cervical cancer (CACX) development, we analyzed the alterations (expression/methylation/deletion/mutation) of RB1/phosphorylated RB1 (p-RB1) (ser807/811 and ser567) and two RB1 phosphorylation inhibitors, P16 and RBSP3, in disease-free normal cervical epithelium (n = 9), adjacent normal cervical epithelium of tumors (n = 70), cervical intraepithelial neoplasia (CIN; n = 28), CACX (n = 102) samples and two CACX cell lines. Immunohistochemical analysis revealed high/medium expression of RB1/p-RB1 (ser807/811 and ser567) and low expression of P16 and RBSP3 in proliferating basal–parabasal layers of majority of normal cervical epitheliums, irrespective of HPV16 infection. Interestingly, 35–52% samples showed high/medium expression of P16 in basal–parabasal layers of normal and had significant association with deleterious non-synonimous SNPs of P16. Methylation of P16 and RBSP3 in basal–parabasal layers of normal cervix (32 and 62%, respectively) showed concordance with their respective expressions in basal–parabasal layers. The methylation frequency of P16 and RBSP3 in basal–parabasal layers of normal did not change significantly in CIN and CACX. The deletion frequency of P16 and RB1 increased significantly with CACX progression. While, deletion of RBSP3 was high in CIN and comparable during CACX progression. P16 showed scattered and infrequent mutation in CACX. The alteration of P16 and RBSP3 was synergistic and showed association with overexpression of p-RB1 in tumors and associated with poor prognosis of patients. Thus, our data suggest that overexpression of p-RB1 in basal–parabasal layers of normal cervical epithelium was due to methylation/low functional-linked non-synonimous SNPs of P16 and RBSP3. This pattern was maintained during cervical carcinogenesis by additional deletion/mutation.


2021 ◽  
Vol 20 ◽  
pp. 153303382098011
Author(s):  
Junjun Shu ◽  
Ling Xiao ◽  
Sanhua Yan ◽  
Boqun Fan ◽  
Xia Zou ◽  
...  

Objective: Ovarian cancer (OC) ranks one of the most prevalent fatal tumors of female genital organs. Aberrant promoter methylation triggers changes of microRNA (miR)-375 in OC. Our study aimed to evaluate the mechanism of methylated miR-375 promoter region in OC cell malignancy and to seek the possible treatment for OC. Methods: miR-375 promoter methylation level in OC tissues and cells was detected. miR-375 expression in OC tissues and cell lines was compared with that in demethylated cells. Role of miR-375 in OC progression was measured. Dual-luciferase reporter gene assay was utilized to verify the targeting relationship between miR-375 and Yes-associated protein 1 (YAP1). Then, Wnt/β-catenin pathway-related protein expression was tested. Moreover, xenograft transplantation was applied to confirm the in vitro experiments. Results: Highly methylated miR-375 was seen in OC tissues and cell lines, while its expression was decreased as the promoter methylation increased. Demethylation in OC cells brought miR-375 back to normal level, with obviously declined cell invasion, migration and viability and improved apoptosis. Additionally, miR-375 targeted YAP1 to regulate the Wnt/β-catenin pathway protein expression. Overexpressed YAP1 reversed the protein expression, promoted cell invasion, migration and viability while reduced cell apoptosis. Overexpressed miR-375 in vivo inhibited OC progression. Conclusion: Our study demonstrated that demethylated miR-375 inhibited OC growth by targeting YAP1 and downregulating the Wnt/β-catenin pathway. This investigation may offer novel insight for OC treatment.


Blood ◽  
2006 ◽  
Vol 108 (12) ◽  
pp. 3881-3889 ◽  
Author(s):  
Joel G. Turner ◽  
Jana L. Gump ◽  
Chunchun Zhang ◽  
James M. Cook ◽  
Douglas Marchion ◽  
...  

AbstractWe investigated the role of the breast cancer resistance protein (BCRP/ABCG2) in drug resistance in multiple myeloma (MM). Human MM cell lines, and MM patient plasma cells isolated from bone marrow, were evaluated for ABCG2 mRNA expression by quantitative polymerase chain reaction (PCR) and ABCG2 protein, by Western blot analysis, immunofluorescence microscopy, and flow cytometry. ABCG2 function was determined by measuring topotecan and doxorubicin efflux using flow cytometry, in the presence and absence of the specific ABCG2 inhibitor, tryprostatin A. The methylation of the ABCG2 promoter was determined using bisulfite sequencing. We found that ABCG2 expression in myeloma cell lines increased after exposure to topotecan and doxorubicin, and was greater in logphase cells when compared with quiescent cells. Myeloma patients treated with topotecan had an increase in ABCG2 mRNA and protein expression after treatment with topotecan, and at relapse. Expression of ABCG2 is regulated, at least in part, by promoter methylation both in cell lines and in patient plasma cells. Demethylation of the promoter increased ABCG2 mRNA and protein expression. These findings suggest that ABCG2 is expressed and functional in human myeloma cells, regulated by promoter methylation, affected by cell density, up-regulated in response to chemotherapy, and may contribute to intrinsic drug resistance.


2010 ◽  
Vol 103 (2) ◽  
pp. 287-296 ◽  
Author(s):  
Mehdi H. Shahi ◽  
Mohammad Afzal ◽  
Subrata Sinha ◽  
Charles G. Eberhart ◽  
Juan A. Rey ◽  
...  

2017 ◽  
Vol 443 (1-2) ◽  
pp. 121-130 ◽  
Author(s):  
Chandraditya Chakraborty ◽  
Sudip Samadder ◽  
Anirban Roychowdhury ◽  
Anup Roy ◽  
Pradip Das ◽  
...  

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