Expression of c-myc protein is related to cell proliferation and expression of growth factor receptors in transitional cell bladder cancer

Archival biopsy specimens from transitional cell bladder tumours (n=185) were analysed immunohistochemically for expression of c-myc protein. The results were compared with compared with histopathological and clinical parameters and survival. Forty-three per cent of the tumours were negative for c-myc protein and weak, moderate, or strong cytoplasmic expression was found in 34, 14, and 9 per cent of cases, respectively. Nuclear positivity for c-myc protein was detected in 35 per cent of tumours and nuclear opositivity was related to overexpression of c-erb B-2 (P=0.01) and a high proportion of nuclei were also positive for p53 oncoprotein (p<0.05). Cytoplasmic expression of c-myc protein was related to histological grade (P=0.005), papillary status (P=0.007), the S-phase fraction (P=0.008), the mitotic index (P=0.021), overexpression of epidermal growth factor receptor (P=0.045), and c-erb B-2 (P=0.17). Expression of c-myc protein was not significantly related to the progression of tumours and it had no prognostic value in survival analysis. Independent predictors were the T-category (P<0.001), papillary status. (P=0.001), and S-phase fraction (P=0.061). The results show that while c-myc gene product participates in growth regulation of human bladder cancer cells, it has no independent prognostic significance.     

Expression of oncoproteins in primary human non-small cell lung cancer and incidence of metastases

In the current study the relationship between the incidence of metastatic spread and expression (at the protein level) of various proto-oncogenes was investigated in 217 human non-small cell lung carcinomas. Tumors with an overexpression of proteins encoded by the oncogenes c-jun and c-myc showed a significantly increased formation of metastases (c-jun: P = 0.008; c-myc: P = 0.018). No significant correlations were found between the expression of the c-fos, c-erbB1, c-neu and c-ras products and metastatic spread.     

Expression of platelet-derived growth factor and c-myc in atherosclerotic lesions in cholesterol-fed chickens: immunohistochemical and in situ hybridization study

Immunohistochemical examination showed no significant expression of platelet-derived growth factor-A (PDGF-A), PDGF-B, PDGF receptors, or of c-myc in the thoracic and abdominal aortas of normal roosters. In cholesterol-fed roosters, intense immunohistochemical reaction for PDGF-B, PDGF receptor, and c-myc was seen in the lipid-rich thickened intimal lesions of the thoracic and abdominal aortas while no significant immunoreaction for PDGF-A was demonstrated in the same lesions. In accordance with immunohistochemical findings, in situ hybridization demonstrated a significant level of expression of PDGF-B, PDGF-A receptor, PDGF-B receptor, and c-myc genes in proliferating intimal cells of the thoracic and abdominal aortas. These results suggest that coordinate actions of PDGF-B and c-myc play an important role in proliferation of intimal cells in the developing atherosclerotic lesions in chickens.     

Expression of the c-myc and Ca-ATPase genes in cardiac muscle during adaptation to repeated stress

In the course of adaptation to repeated stress, the expression of the proto-oncogene c-myc found to increase much more rapidly than that of the Ca-ATPase gene. It is suggested that an increase in the level of c-myc expression may activate the structural Ca-ATPase gene and possibly also the heat-shock proteins. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 117, N ^o 2, pp. 124–126, February, 1994     

No correlation of c-myc overexpression and p53 mutations in liposarcomas

 Although it is well known that oncogenesis is a multistep process involving the activation of normal cellular genes to become oncogenes and/or the inactivation of tumor suppressor genes, this process has seldom been investigated in soft tissue tumours. We screened a group of 36 liposarcomas for genetic abnormalitis in the p53 tumour suppressor gene and c-myc oncogene. Altered c-myc gene expression was examined by differential RT-PCR assay. p53 Gene mutations in exons 4–8 were analysed by using PCR-SSCP analysis and direct sequencing. Elevated c-myc expression was found in 6 of 31 liposarcomas (19.4%). p53 Gene mutations were observed in 5 of 36 liposarcomas (13.9%). Both genetic alterations were associated with the histological subtype of liposarcomas. Whereas c-myc gene expression was a characteristic of myxoid/round cell liposarcomas, p53 gene mutations were found more frequently in pleomorphic variants. Liposarcomas of the well-differentiated subtype showed neither p53 gene mutations nor altered c-myc gene expression. Our results indicate that the c-myc oncogene and the p53 tumor suppressor gene do not seem to cooperate in the oncogenesis of liposarcomas. Received: 22 April 1998 / Accepted: 11 May 1998     

Microvessel density, expression of proto-oncogenes, resistance-related proteins and incidence of metastases in primary ovarian carcinomas

Relationships between the incidence of metastatic spread and microvessel density, expression of proto-oncogene products, or expression of resistance-related proteins were investigated in human ovarian carcinomas by immunohistochemistry. Ovarian carcinomas with a high microvessel density showed a significantly increased formation of metastases (P=0.005). Tumors with positive immunoreactivity of c-jun and c-myc products had a higher metastatic spread; however, these results were not statistically significant. A marginally significant correlation existed between the expression of erbB1 (EGFR) and metastatic spread (P=0.05). No significant relationship was found between the expression of the resistance-related proteins P-glycoprotein or glutathione S-transferase- and the incidence of metastases. Furthermore, no correlation was detected between expression of the heat shock protein 70 and the occurrence of metastases.     

Expression and prognostic value of c-erbB-2 oncogene product in human phaeochromocytomas

Aims: Amplification of c-erbB-2 proto-oncogene has been reported in endocrine tumours, but the results were unclear and no predictive prognostic value has been established in the case of phaeochromocytoma. We investigated the immunohistochemical expression of c-erbB-2 oncogene in 34 cases of human phaeochromocytoma (27 sporadic, seven familial type MEN (multiple endocrine neoplasm)) in order to find out if it could be used to differentiate sporadic and familial forms and whether c-erbB-2 expression is related to tumour biological behaviour. Methods and results: All the cases showed diffuse, generally heterogeneous, intracytoplasmic granular c-erbB-2 staining. The percentage of tumour cells expressing c-erbB-2 was used as the comparative variable. The percentage of c-erbB-2 positive cells had a statistically significant (P < 0.001) relationship with tumour aggressiveness, as manifested by the presence of distant metastasis or association with other malignant neoplasms. We also found significantly higher levels (P = 0.007) of c-erbB-2 overexpression in MEN phaeochromocytoma than in sporadic cases. Conclusions: These results clarify the important role of c-erbB-2 proto-oncogene in the pathogenesis of human phaeochromocytoma and confirm the unfavourable prognostic significance of c-erbB-2 expression.     

c-myc GENE ABNORMALITIES IN MUCOSA-ASSOCIATED LYMPHOID TISSUE (MALT) LYMPHOMAS

c-myc gene abnormalities associated with lymphomagenesis, including rearrangements and mutations in the regulatory region between exon I and intron I, have been studied in 54 MALT lymphomas (43 low and 11 high grade) and 36 nodal lymphomas (27 low and 9 high grade). By Southern blot analysis, none of the 54 MALT lymphomas but 2 of 36 nodal lymphomas had c-myc gene rearrangements. Defined tumour cell populations from all MALT lymphoma cases were isolated by microdissection from frozen tissue sections and analysed by polymerase chain reaction–single-strand conformational polymorphism (PCR–SSCP) and direct sequencing for somatic mutations in the exon I/intron I region of the gene. Point mutations in this region were identified in nine cases of MALT lymphoma (7/43=16·2 per cent of low grade; 2/11=18·1 per cent of high grade). These mutations were located at either the exon I/intron I border of myc intron factor (MIF) binding sites, which are critical in the negative regulation of c-myc expression. Of the nodal lymphomas, only the two cases (5·6 per cent) with c-myc gene rearrangement showed scattered or clustered mutations. These results suggest that c-myc mutations in MALT lymphomas are unlikely to be associated with chromosome translocation, which is the main cause of somatic mutations observed in other types of lymphoma. The mutations involving the c-myc regulatory regions may play a pathogenetic role in at least a proportion of MALT lymphomas. © 1997 by John Wiley & Sons, Ltd.     

INVERSE CORRELATION BETWEEN EXPRESSION OF HLA-B AND c-myc IN UVEAL MELANOMA

HLA class I is expressed in 75–85 per cent of uveal melanoma and cytoplasmic c- myc expression has been reported in 78 per cent of uveal melanoma. In skin melanoma, an inverse relationship has been observed between HLA class I expression and c- myc . The purpose of this study was to determine whether a similar correlation occurred between high expression of c- myc and low expression of HLA class I in uveal melanoma. The expression of c- myc , HLA-A, and HLA-B was determined by immunohistochemistry on formalin-fixed and paraffin-embedded sections of 30 uveal melanomas. Cell cultures from four primary uveal melanomas (lines 92-1, MEL 202, OCM-1, and EOM-3) and one uveal melanoma metastasis (line OMM-1) were tested for mRNA levels of c- myc and HLA-A and HLA-B in Northern blot assays. The high level of expression of cytoplasmic c- myc was significantly correlated with low expression of HLA-B ( P =0·03) and vice versa. High expression of HLA-B was significantly correlated with the presence of epithelioid cells ( P =0·004). The inverse correlation observed between c- myc and HLA-B expression is similar to previous observations in cutaneous melanoma. By downregulating HLA-B expression, c- myc may influence the immune response in uveal melanoma. Tumours containing epithelioid cells showed a significantly higher expression of HLA-B than tumours of the spindle cell type. © 1997 by John Wiley & Sons, Ltd.     

Analysis of c-myc DNA amplification in non-small cell lung carcinoma in comparison with small cell lung carcinoma using polymerase chain reaction

Previous studies of c-myc DNA amplification in lung cancer have focused primarily on analysis of small cell carcinoma or its tumor cell lines. There are few data about c-myc DNA amplification in histological types of lung cancer other than small cell carcinoma. Therefore the present study was conducted to investigate c-myc oncogene amplification in non-small cell lung carcinoma. We studied 46 lung tumor specimens for c-myc DNA amplification (15 adenocarcinomas, 15 squamous cell carcinomas, 6 large cell carcinomas, and 10 small cell carcinomas). Polymerase chain reaction, digoxigenin DNA labeling, and elecrophoresis were utilized to investigate the c-myc copy number in the lung tumor specimens. The c-myc copy number of non-small cell carcinoma ranged from 1.5 to more than 20.0 in adenocarcinoma and squamous cell carcinoma, and from 6.0 to 12.0 in large cell carcinoma. That of small cell carcinoma ranged from 1.8 to 12.0. The c-myc copy number of non-small cell carcinoma was significantly higher that than of small cell carcinoma (Wilcoxon rank sum test, Z=2.06, P=0.040). However, the differences in c-myc copy number among these four histological types were not statistically significant. Amplification of c-myc (more than 4 copies) was observed not only in small cell carcinoma but also in non-small cell carcinoma at similarly high frequency (12/15 in adenocarcinoma and squamous cell carcinoma, 6/6 in large cell carcinoma, and 9/10 in small cell carcinoma). Received: 17 October 2000 / Accepted: 7 May 2001     

Expression of HSP90 in gastrointestinal stromal tumours and mesenchymal tumours

Kang G H, Lee E J, Jang K T, Kim K‐M, Park C K, Lee C‐S, Kang D Y, Lee S H, Sohn T S & Kim S
(2010) Histopathology 56, 694–701
Expression of HSP90 in gastrointestinal stromal tumours and mesenchymal tumours Aims: Heat shock proteins (HSP) are up‐regulated under conditions of increased stress, including cancer. Recently, HSP90 has been shown to be crucial to the expression and activation of the KIT oncoprotein. The aim was to explore the role of HSP90 expression as a prognostic marker and therapeutic target in gastrointestinal stromal tumours (GISTs) and other mesenchymal tumours. Methods and results: The expression of HSP90 was evaluated by immunohistochemistry in 92 GISTs, 47 mesenteric fibromatoses, six schwannomas, leiomyomas, melanomas, malignant peripheral nerve sheath tumours and leiomyosarcomas. Western blotting was performed in 22 selected cases. HSP90 overexpression was found in 33.7% of GISTs and was correlated with non‐gastric location, mixed histological subtype, high mitotic index, high risk grades, and specific mutation genotypes. In mesenchymal tumours, HSP90 overexpression was found in 66.7% of malignant peripheral nerve sheath tumours, 83.3% of leiomyosarcomas, and 100% of melanomas. HSP90 expression by Western blotting correlated with the results of immunohistochemistry. The Cox proportional hazards model showed that HSP90 expression is an independent predictor of recurrence in GISTs (P = 0.003). Conclusions: Overexpression of HSP90 is predictive of adverse behaviour in GISTs and may provide a therapeutic solution to the challenge of imatinib‐resistant GISTs and other mesenchymal sarcomas.     

Interleukin 8 serum concentration,but not lactate dehydrogenase activity,positively correlates to CD34 antigen in melanoma tumors

CD34 promotes melanoma cell motility, negative regulation of cellular response to hypoxia and positive regulation of vasculogenesis. Interleukin 8 (IL-8) is responsible for angiogenic response in endothelial cells, increases proliferation, metastasis, and survival of melanoma cells. The aim of our study was evaluation of relationship between CD34 immunoexpression and IL-8 serum concentrations in melanoma patients. The study was conducted on patients with melanoma that were divided in: Clark II (17 patients – 19.3%), Clark III (33 patients – 37.5%), Clark IV (22 patients – 25%), and Clark V (16 patients – 18.2%) levels. CD34 expression was absent for Clark II melanomas, and positive for Clark III (6.1%), Clark IV (40.9%), and Clark V (56.2%). The CD34 immune-mark was highly positive only for Clark IV and V levels. Interleukin 8 (IL-8) had high values (above 15 pg/mL) for all patients with melanoma (58.9% - Clark II; 87.8% - Clark III; 90.9% - Clark IV and 93.7% - Clark V). We have found a strong and statistically significant correlation between CD34 and IL-8 for Clark IV (r = 0.54, P < 0.05) and Clark V (r = 0.72, P < 0.05) melanomas. CD34 and IL-8 are associated with poor prognosis of melanoma, metastasis, and neoangiogenesis.     

Analysis of c-fos,c-jun,c-erbB1, c-erbB2 and c-myc in primary lung carcinomas and their lymph node metastases

The purpose of this study was to identify possible alterations in proto-oncogenes (c-fos, c-jun, c-erbB1, c-erbB2 and c-myc) at the protein level in primary lung carcinomas and simultaneous metastatic lymph nodes of 21 patients. The analysis showed that proteins of c-jun and c-myc were expressed in a significantly higher frequency in metastases than in primary lung tumors. Gross differences were not found between primary tumors and metastatic tumors with regard to the expression of c-erbB1, c-erbB2 and c-fos. The finding of cases with a higher expression of c-jun and c-myc in lymph nodes suggests that metastatic capability may be higher in certain cell populations.     

Macrophage Priming and Activation During Fibrosarcoma Growth: Expression of c-myb,c-myc,c-fos,and c-fms

Macrophages (M?)³ function by a two-step process that includes priming (induction of cytokine and enzyme mRNA) and activation (production of effector molecules). The initial steps in M? priming involve the expression of certain proto-oncogenes that regulate expression of other genes. Because tumor growth primes M? to produce several suppressor monokines, we determined if cancer induced M? expression of these proto-oncogenes. Unstimulated peritoneal M? from tumor-bearing hosts (TBH) constitutively expressed the proto-oncogenes c-fms, c-fos, c-myc, and c-myb, whereas normal host (NH) M? had little or no expression of these proto-oncogenes. When M? were given a 24-h adherence priming stimulus, NH M? expressed c-fms and c-fos at levels equivalent to TBH M? constitutive expression. Adherence had little or no effect on c-fms and c-fos expression in TBH M? or on NH and TBH M? c-myc expression. c-myb expression was not induced in NH M? during adherence and was strongly decreased in TBH M?. Activation with a 1-h lipopolysaccharide-treatment increased NH and TBH M? expression of c-fms, c-fos, and c-myc, with higher expression of these proto-oncogenes in TBH M?. Activation failed to induce c-myb expression in NH M? and completely inhibited expression in TBH M?. Because c-fms, c-fos, and c-myc are normally expressed early during M? activation, our results suggest that tumor growth primes M? by inducing expression of these proto-oncogenes. c-myb is expressed in immature M? and is downregulated during M? activation. These observations explain why NH M? expression of c-myb was not induced and are consistent with reports that suggest TBH M? have not reached full developmental maturity. The induction of M? protooncogene expression during cancer may put M? in a primed state, which leads to earlier and stronger production of adverse suppressor and cytotoxic molecules.     

Immunohistochemical localization of c-erbB-2 protein and epidermal growth factor receptor in normal surface epithelium,surface inclusion cysts,and common epithelial tumours of the ovary

Summary The c-erbB-2 (HER-2/neu) protein is a membrane glycoprotein growth factor receptor showing molecular homology with the epidermal growth factor receptor (EGFR). We examined the immunohistochemical reactivity of monoclonal antibodies against both of these proteins in normal surface epithelium, surface inclusion cysts, and common epithelial tumours of the ovary. The ovarian tumours were classified as benign (16), borderline malignant (2), and malignant (19). Normal surface ovarian epithelium was weakly positve for both c-erbB-2 protein and EGFR. In surface inclusion cysts, however, the epithelial cells lining the lumen exhibited stronger staining for c-erbB-2 protein, but no staining for EGFR. All 16 benign ovarian tumours and the 2 borderline malignant ovarian tumours were positive for c-erbB-2 protein and negative for EGFR. Of the ovarian carcinomas, 13 of the 19 (68.4%) were positive for c-erbB-2 protein and negative for EGFR, while 4 showed positivity for both c-erbB-2 protein and EGFR. Two cases were negative for both proteins. Expression of both c-erbB-2 protein and EGFR was found in endometrioid carcinoma with squamous differentiation and in clinically advanced poorly differentiated serous carcinomas. Expression of c-erbB-2 protein appears to be increased and that of EGFR is reduced in the early stage of epithelial ovarian oncogenesis. The expression of EGFR with c-erbB-2 protein in ovarian carcinoma is related both to histological differentiation and/or advanced clinical stage.     

Tumour progression and metastatic behaviour in vivo correlates with integrin expression on melanocytic tumours

In order to evaluate the significance of adhesion molecules expressed on melanocytic tumours for progression and prognosis in vivo, we studied integrin expression (VLA-1 to VLA-6, CD18, CD51, CD61) on 10 naevi, 40 primary malignant melanomas, and 11 metastases by immunohistology using the APAAP technique. Evaluation was done by grouping the percentage of positive tumour cells in six categories. Statistical analysis (Wilcoxon rank test, Scheffe test) revealed significant differences in the expression of VLA-1 (P <0.0001), VLA-2 (P=0.0001), VLA-5 (P=0.0093), VLA-6 (P=0.0232), and CD61 (P0.0002) between naevi and primary melanomas. Comparing primary melanomas with metastases, a statistically significant decrease in the expression of VLA-1, VLA-2, and VLA-6 was detectable, as well as a significant increase in VLA-4 and VLA-5. There was no correlation between integrin expression and tumour type (superficial spreading melanoma, nodular melanoma, lentigo maligna melanoma), regression and ulceration. Changes of VLA-1, VLA-4, and VLA-6 expression correlated with the tumour thickness of the primary melanoma, but only VLA-4 and VLA-6 expression on primary melanomas correlated significantly with the development of metastases (P=0.024 and P=0.001). These changes of integrin expression during tumour progression particularly, the data showing an increase of VLA-4, and a decrease of VLA-6 expression support the concept that integrins are a new additional set of prognostic markers which indicate predisposition to the development of metastases.     

Cytomorphological,cytogenetic, and molecular biological characterization of four new human renal carcinoma cell lines of the clear cell type

Four new permanent cell lines (RCC-A, -B,-C, and -D) derived from different human renal cell carcinomas of the clear cell type were established in tissue culture. The cell lines displayed characteristic differences in cell size and shape, which allowed individual identification by phase contrast microscopy. Ultrastructurally, the cell lines exhibited varying amounts of cytoplasmatic glycogen and lipid. Immunohistochemistry revealed co-expression of vimentin and cytokeratin in all cell lines. The mean population doubling time ranged from 27 h (RCC-A) to 104 h (RCC-D). RCC-B and -C cells produced slowly growing tumours after heterotransplantation into nude mice, whereas RCC-A and RCC-D cells were non-tumorigenic. The modal chromosome number was either near-diploid (RCC-A, -B, and -C) or near triploid (RCC-D). Clonal abnormalities affecting the short arm of chromosome 3 were seen in all cell lines. Northern blot analysis revealed no expression of the proto-on-cogenes c-fos, c-ros, and c-mos, whereas c-Ki-ras expression was observed in all cell lines. Expression of c-myc was observed in RCC-A, RCC-B, and RCC-D cells, whereas c-raf expression could be detected in RCC-B and RCC-D. Tumour suppressor gene p53 mRNA was observed in the cell line RCC-D.