Bag‐1 Expression as a Prognostic Factor in Tongue Squamous Cell Carcinomas

Abstract

Correlation between Bag-1 expression and other biologic variables revealed that Bag-1 might be involved in several biologic processes including apoptosis and cell proliferation. The expression of Bag-1 protein, particularly in combination with Bax expression or AI, respectively, has prognostic value in oral tongue SCC.

Subcellular localisation of BAG-1 and its regulation of vitamin D receptor-mediated transactivation and involucrin expression in oral keratinocytes: Implications for oral carcinogenesis

“…Since subcellular localisation of BAG-1 changes with differentiation in different tissues [2], and in oral cancers in vivo there appears to be a shift from nuclear to cytoplasmic expression [11,12], the localisation of specific BAG-1 isoforms may be important in differentiation and carcinogenesis and also their ability to modulate VDR activity. However, the localisation of the different BAG-1 isoforms has not been investigated in keratinocytes.…”

“…BAG-1 proteins regulate key cellular processes through interaction with a wide range of proteins, including anti-apoptotic protein Bcl-2 [3], molecular chaperone 70 kDa heat shock proteins (Hsc70/Hsp70) [4,5], serine/threonine kinase Raf-1 [6], Rb [7], nuclear receptors (NRs) and growth factor receptors [reviewed in 8]. BAG-1 is overexpressed in many cancers [9], including oral squamous cell carcinomas where the overexpression correlates with the presence of associated lymph node metastases [10] and with poor prognosis [11]. Our studies revealed that although BAG-1 is highly expressed in lymph node metastases, primary oral squamous cell carcinomas show reduced nuclear BAG-1 staining compared to normal epithelium, suggesting alteration in localisation of BAG-1 proteins during oral carcinogenesis.…”

Co-overexpression of Bag-1 and heat shock protein 70 in human epidermal squamous cell carcinoma: Bag-1-mediated resistance to 5-fluorouracil-induced apoptosis

“…Shindoh et al (2000) reported that small primary oral tumours (T1 and T2) that had associated lymph node metastases tended to show strong Bag-1 staining. Indeed, Xie et al (2004) suggested that strong Bag-1 staining may be an indicator of poor prognosis for tongue SCC, a particularly aggressive subset of oral cancer.…”

“…Bag-1 has been implicated as a prognostic marker in oral SCC, showing correlation with overexpression of Bcl-2 (Xie et al , 2004) and Hsp70 (Weber et al , 2007). Three major Bag-1 isoforms are expressed in human cells, Bag-1S, Bag-1M and Bag-1L, with molecular sizes of 36, 46 and 50 kDa, respectively.…”

Nuclear or cytoplasmic localization of Bag-1 distinctly correlates with pathologic behavior and outcome of gastric carcinomas

“…Expression of Bag-1 in the nucleus is reported to correlate with unfavorable clinical outcomes in esophageal and colorectal cancers [17,25]. Higher Bag-1 expression indicates a poor prognosis in breast and tongue SCC [37,38]. In contrast, cytoplasmic expression is suggested to prolong survival in nonsmall cell lung cancer [12].…”