Heat-shock protein 70-2 (HSP70-2) expression in bladder urothelial carcinoma is associated with tumour progression and promotes migration and invasion.
OBJECTIVE
Testis specific heat-shock protein 70-2 (HSP70-2), a member of HSP70 chaperone family, is essential for the growth of spermatocytes and cancer cells. We investigated the association of HSP70-2 expression with clinical behaviour and progression of urothelial carcinoma of bladder.


METHODS
We assessed the HSP70-2 expression by RT-PCR and HSP70-2 protein expression by immunofluorescence, flow cytometry, immunohistochemistry and Western blotting in urothelial carcinoma patient specimens and HTB-1, UMUC-3, HTB-9, HTB-2 and normal human urothelial cell lines. Further, to investigate the role of HSP70-2 in bladder tumour development, HSP70-2 was silenced in the high-grade invasive HTB-1 and UMUC-3 cells. The malignant properties of urothelial carcinoma cells were examined using colony formation, migration assay, invasion assay in vitro and tumour growth in vivo.


RESULTS
Our RT-PCR analysis and immunohistochemistry analysis revealed that HSP70-2 was expressed in both moderate to well-differentiated and high-grade invasive urothelial carcinoma cell lines studied and not in normal human urothelial cells. In consistence with these results, HSP70-2 expression was also observed in superficially invasive (70%) and muscle-invasive (90%) patient's tumours. Furthermore, HSP70-2 knockdown significantly suppressed cellular motility and invasion ability. An in vivo xenograft study showed that inhibition of HSP70-2 significantly suppressed tumour growth.


CONCLUSIONS
In conclusion, our data suggest that the HSP70-2 expression is associated with early spread and progression of urothelial carcinoma of bladder cancer and that HSP70-2 can be the potential therapeutic target for bladder urothelial carcinoma.
Garg
Manoj
M
National Institute of Immunology, New Delhi, India.
Kanojia
Deepika
D
Seth
Amlesh
A
Kumar
Rajive
R
Gupta
Anju
A
Surolia
Avadhesha
A
Suri
Anil
A
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002295:Carcinoma, Transitional Cell / Q000378:metabolism* / Q000473:pathology; D002455:Cell Division; D002465:Cell Movement; D018450:Disease Progression; D015536:Down-Regulation; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D055785:Gene Knockdown Techniques; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D014183:Transplantation, Heterologous; D014407:Tumor Cells, Cultured; D001749:Urinary Bladder Neoplasms / Q000378:metabolism* / Q000473:pathology; D055815:Young Adult
D014408:Biomarkers, Tumor; D018840:HSP70 Heat-Shock Proteins; C525621:HSPA1B protein, human; D009363:Neoplasm Proteins; D012333:RNA, Messenger