Effect of Culture at Low Oxygen Tension on the Expression of Heat Shock Proteins in a Panel of Melanoma Cell Lines

Tumours are commonly hypoxic and this can be associated with aggressive tumour type, metastasis and resistance to therapy. Heat shock proteins (hsps) are induced in response to hypoxia, provide cancer cells with protection against tumour-associated stressors and chaperone oncoproteins that drive tumour proliferation. This study examined the effect of different oxygen concentrations on the expression of hsps in melanoma cell lines.Melanoma cell lines were cultured in 2% and 20% O(2). Expression of Hsp90, Hsp70, Hsp60, Hsp40 and Hsp32 proteins were determined by flow cytometry.Growth rates and viability were reduced in the majority of cell lines by culture in 2% O(2). Hsp expression was different in 2% compared to 20% O(2) and changes in Hsp90 expression correlated with cell line generation time (P<0.005) and viability (P<0.01). Greater total hsp expression correlated with improved viability in 2% but not 20% O(2) (P<0.05). Relative expression of the different hsps was consistent across cell lines and each correlated with the others (P = 0.0001) but not with Hsp32. Hsp expression was inversely correlated with cell line adhesion to laminin as well as collagen type IV and Breslow depth of the original primary tumour tissue (P<0.05), but not with Clark level or patient survival. All five hsps were identified on the cell surface.Culture in 2% O(2) variably altered hsp expression in a panel of melanoma cell lines. Hsp expression was associated with certain cell line characteristics and clinical parameters of the originating tumour

Long-term prognostic significance of HSP-70, c-myc and HLA-DR expression in patients with malignant melanoma

Aim: Use of molecular markers indicative of the tumour oncogenic potential and host response may enhance our prognostic information for more effective treatment of melanoma patients. The roles of HSP-70 protein, c-myc oncogene and HLA-DR antigen expression were examined in melanoma patients and related to prognostic factors, recurrence rate and long-term survival. Methods: Forty patients with tumours thicker than I mm were included in this study. All had elective node dissection and were followed for at least 7 years. Twenty-two had microscopic nodal metastases. Both primary melanoma tumour and lymph nodes were examined for the immunohistochemical expression of HSP-70 protein, c-myc oncogene and HLA-DR antigen. Results: Eighteen patients had a recurrence (45%) and 23 patients survived overall (57.50%). Positive HSP-70 expression was observed in 52.50% of the primary melanomas and was associated with improved overall survival, especially in the patient group with tumours greater than or equal to1.5 mm (70% vs 26.70%, P = 0.0159). C-myc oncogene was overexpressed in 47.50% and HLA-DR antigen in 42.50% of the primary melanomas, but no correlation with survival was observed. The expression profile of these molecular markers in the primary tumour did not predict the status of regional nodes. HLA-DR expression in lymph nodes was observed exclusively in the nodal tissue surrounding the metastatic melanoma tumour in five patients. Conclusions: The immunohistochemical expression profile of HSP-70 but not of c-myc oncogene or HLA-DR antigen in the primary melanoma tumour could be of certain value in the identification of patients with graver prognosis who may benefit from more aggressive therapeutic strategies, (C) 2001 Harcourt Publishers Ltd

Common prognostic factors for stage III melanoma patients and for stage I and II melanoma patients with recurrence to their regional lymph nodes

This study was undertaken in order to identify the prognostic factors for stage III malignant melanoma patients. In addition we compared the survival data of these patients with data from patients presenting with stage I and II disease who subsequently developed a regional nodal recurrence, in order to identify common prognostic factors and to compare the biological behaviour of the two groups. We retrospectively examined two groups of patients. The first consisted of 116 patients with stage III malignant melanoma and the second consisted of 57 patients with stage I and II malignant melanoma that were found to have regional lymph node metastases diagnosed at least 6 months after surgical treatment of their primary lesion. The age of the patients, the number of disease-involved lymph nodes, the site of the primary lesion and the presence or not of palpable lymph nodes proved to be significant prognostic factors of the first group. We also analysed the survival data of the second group and compared it with data from the stage III patients. The 5 year survival starting from the time after diagnosis of the primary lesion was 47.37% compared with 25.86% in stage III patients; however, this difference was not statistically significant. Patients who present with stage III malignant melanoma seem to have a more aggressive phenotype than stage I and II malignant melanoma patients who present with recurrent disease in their regional lymph nodes. Disease behaviour is dictated by the number of disease-involved lymph nodes, the site of the primary lesion and the type of surgical procedure performed (elective or therapeutic lymph node dissection). (C) 2002 Lippincott Williams Wilkins

Long term effect of splenectomy on patients operated on for cancer of the left colon: a retrospective study.

To find out if accidental splenectomy during colonic resection influences the survival of patients with colon cancer. Retrospective clinical study. University hospital, Greece. Twenty-five patients with colonic cancer (13 Dukes' B and 12 Dukes' C) who had accidental splenectomy during resection of the left colon (n = 22) or the sigmoid (n = 3) between 1973 and 1990. Each study patient was matched with control patients for age, sex, Dukes' stage, grade, site of tumour, date, type of operation and number of blood transfusions. The five year actuarial and disease free survival estimated by the Kaplan-Meier product limit method. There were significantly more infective postoperative complications (6/25 compared with 0/25, p = 0.02) in patients who had a splenectomy. The incidence of metastases (p = 0.07) and the five-year disease free (p = 0.08) and overall survival (p = 0.1) were lower but not significantly so in patients who had a splenectomy compared with controls. Splenectomy significantly increases the number of infective postoperative complications in patients with colonic cancer. Although there was a trend for shorter disease-free survival after splenectomy, it seems that splenectomy had no impact on survival

Hsps are up-regulated in melanoma tissue and correlate with patient clinical parameters

Heat shock proteins (hsps) have been studied in numerous cancer types, but a clear view of their clinical relevance in melanoma remains elusive. Therefore, the aim of this study was to investigate the expression of hsps in melanoma with respect to patient clinical parameters. Using Western immunoblotting, hsps 90, 70, 60, 40 and 32 were observed to be widely expressed in metastatic melanomas (n = 31), while immunofluorescence demonstrated that in the majority of samples these hsps, apart from hsp32, were increased in expression in melanoma cells compared with surrounding non-melanoma cells in situ (n = 8). Correlating hsp expression with patient clinical parameters indicated that greater hsp90 (P < 0.02) and hsp40 (P < 0.03) expression correlated with advanced stage (stage III Vs stage IV), while in the case of hsp40, this was additionally associated with reduced patient survival (P < 0.05). In contrast, higher hsp32 expression was associated with improved patient survival (P < 0.007). On the other hand, the expression of the other hsps did not correlate with any obtainable patient clinical parameters. This study provides further evidence for the importance of hsps in melanoma and for their use as therapeutic targets and biomarkers, but larger-scale follow-up studies are required to confirm these results. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s12192-012-0363-1) contains supplementary material, which is available to authorized users