Immunohistochemical expression of proliferative markers in renal cell carcinoma.

PURPOSE: The purpose of this study was to investigate into the expression of cyclin A and telomerase in renal cell carcinoma (RCC) and to analyze the relationship between expression and the clinicopathological characteristics of the tumor and their impact on survival. METHODS: The overall material included 74 samples of RCC and 4 of normal renal tissue. Primary cyclin A antibody from Santa Cruz Biotechnology and TERT MA5-16034 antibody from Thermo Fisher Scientific Inc were used. Staining was performed by streptavidin-biotin technique using DAKO LSAB+ kit. Statistical analyses were performed using of SPSS 23 Statistics software from IBM. RESULTS: No differences in cyclin A and telomerase expression among gender and age groups were found, nor did the tumor dimensions have any significant impact on expression. Also, tumor grades and stages did not differ. However, histological types differed in favor of the papillary type. A significant positive correlation between both markers, as well as between the expression and tumor stage and grade was noticed. Only the tumor stage had negative impact on survival. CONCLUSIONS: Although not affecting survival, the expression of cyclin A and telomerase increased with tumor stage and grade, suggesting that cyclin A and telomerase could be potential proliferative immunohistochemical markers of RCC.

HTERT promoter methylation and single nucleotide polymorphism (-245 T>C) affect renal cell carcinoma behavior in Serbian population.

PURPOSE: Renal cell carcinoma (RCC) is the most common renal cancer in adults and includes several subtypes that may be distinguished by their histology, genetic background, clinical course and responses to treatment. Human telomerase reverse transcriptase (hTERT), a crucial enzyme for telomere maintenance, has been linked to RCC development. The purpose of this study was to search for genetic and epigenetic alterations in hTERT (promoter mutations and methylation and gene amplification), and to establish a possible association between molecular and clinico-pathological characteristics of RCC. METHODS: DNA was extracted from 31 formalin-fixed, paraffin-embedded tumor samples and 23 blood samples from 54 patients with RCC. Polymerase chain reaction (PCR) products were sequenced and analyzed using the Sequencher software. HTERT amplification was determined by quantitative PCR, while the promoter methylation status was assessed by methylation specific PCR. Statistical analysis was performed using SPSS. RESULTS: No mutations could be detected in the hTERT promoter but only a single nucleotide polymorphism (SNP) (-245 T>C). In 54 analyzed RCC cases, the variant allele C was present in homozygous or heterozygous form in 48% of the patients. The C allele was significantly more frequent in low grade tumors (p=0.046). Gene amplification was detected in 19.4% of the 31 RCCs and hTERT methylation in 54.8% of the 31 samples. An association was established between methylation and histological type of RCC (p=0.047). CONCLUSIONS: HTERT seems to be implicated in RCC pathogenesis since the promoter polymorphism exerts a modulation effect on tumor behavior. In addition, hTERT promoter methylation status is related to RCC histology.

Immunohistochemical study of cyclin A and p16 expression in patients with renal cell carcinoma.

PURPOSE: Renal cell carcinoma (RCC) is the most common malignant kidney tumor in adults. Dysregulation of the cell cycle can lead to cancer development. In this study, the mitosis-associated cyclin A and p16, a negative controller, were investigated as potential key points in the RCC development. METHODS: This retrospective study included 74 patients with RCC. The expression of cyclin A and p16 and their correlation to histopathological parameters (TNM stage, histological subtype, nuclear grade, tumor size), gender, age, and clinical outcome were studied and analyzed. RESULTS: The highest median value for cyclin A (40%; range 0-70)) and for p16 (57.5%); range 35-80) were found in the papillary histological subtype. Survival analysis showed that in the group of patients that had died before September 2015, the median value for cyclin A was 20% (range 0-60), which was significantly higher than 5% (range 0-70), found in the group of patients that survived (p=0.019). CONCLUSIONS: In relation to the histological subtype, the papillary type of RCC was associated with a significantly higher expression of cyclin A and p16 compared to other subtypes of RCC. High expression of cyclin A indicated worse prognosis, therefore cyclin A could be considered to be a significant prognostic marker.

Friend or foe: ABCG2, ABCC1 and ABCB1 expression in triple-negative breast cancer.

BACKGROUND: ATP-binding cassette (ABC) transporters are responsible for the efflux of a wide variety of anti-cancer agents and have been implicated in the chemoresistance of various solid tumors. Chemoresistance is a major cause of therapeutic failure, especially in the highly aggressive triple-negative breast cancer (TNBC) in which, unlike estrogen receptor-expressing (ER+) BC, both endocrine and targeted treatments are ineffectual. We aimed to investigate the level and frequency of expression of the three most important ABC transporter, ABCG2, ABCC1, and ABCB1, according to breast cancer subtype. METHODS: We evaluated ABCG2, ABCC1, and ABCB1 protein expressions in 124 primary breast tumors (78 samples were classified as TNBC, while 46 were classified as ER+) by immunohistochemistry and correlated it to clinicopathological characteristics and outcome. RESULTS: All three transporters had significantly higher expression and were more frequently expressed in TNBC compared to ER+ tumors (p < 0.0001). ABCG2 and ABCC1 had a very high level of expression in TNBC that was significantly greater compared to ABCB1 (p < 0.0001). ABCB1 expression was associated with TNBC metastatic spread (p = 0.03). In contrast, TNBC patients with high ABCG2 expression level had significantly longer disease-free interval (p = 0.03) and overall survival (p = 0.007). CONCLUSION: ABCG2, ABCC1, and ABCB1 expression in breast cancer is subtype-specific and associated with triple-negative tumors. The expression of ABCB1 may be useful as a marker of metastatic spread. Moreover, unexpectedly, our results showed a beneficial effect of ABCG2 expression on TNBC clinical behavior. These findings could have implications for the implementation of future TNBC treatment strategies.

Role of PTEN, PI3K, and mTOR in Triple-Negative Breast Cancer.

Breast cancer is the most commonly occurring malignancy and the leading cause of cancer-related death in women. Triple-negative breast cancer (TNBC) is the most aggressive subtype and is associated with high recurrence rates, high incidence of distant metastases, and poor overall survival. The aim of this study was to investigate the PI3K/PTEN/Akt/mTOR pathway as one of the most frequently deregulated pathways in cancer. We aimed to explore the impact of PI3K and mTOR oncogenes as well as the PTEN tumor suppressor on TNBC clinical behavior, prognosis, and multidrug resistance (MDR), using immunohistochemistry and copy number analysis by quantitative real-time PCR. Our results revealed that loss of PTEN and high expression of PI3K and mTOR proteins are associated with poor outcome of TNBC patients. PTEN deletions appeared as a major cause of reduced or absent PTEN expression in TNBC. Importantly, homozygous deletions of PTEN (and not hemizygous deletions) are a potential molecular marker of metastasis formation and good predictors of TNBC outcome. In conclusion, we believe that concurrent examination of PTEN/PI3K/mTOR protein expression may be more useful in predicting TNBC clinical course than the analysis of single protein expression. Specifically, our results showed that PTEN-reduced/PI3K-high/mTOR-high expression constitutes a 'high risk' profile of TNBC.

Importance of Copy Number Alterations of FGFR1 and C-MYC Genes in Triple Negative Breast Cancer.

BACKGROUND: Triple negative breast cancer (TNBC) is characterized by aggressive clinical course and is unresponsive to anti-HER2 and endocrine therapy. TNBC is difficult to treat and is often lethal. Given the need to find new targets for therapy we explored clinicopathological significance of copy number gain of FGFR1 and c-MYC. Our aim was to determine the impact of FGFR1 and c-MYC copy number gain on clinical course and outcome of TNBC. METHODS: FGFR1 and c-MYC gene copy number alterations were evaluated in 78 archive TNBC samples using TaqMan based quantitative real time PCR assays. RESULTS: 50% of samples had increased c-MYC copy number. c-MYC copy number gain was associated with TNBC in contrast to ER positive cancers. Our results showed significant correlation between c-MYC copy number gain and high grade of TNBCs. This suggests that c-MYC copy number could be an useful prognostic marker for TNBC patients. c-MYC copy number gain was associated with high pTNM stage as well as lobular and medullary tumor subtypes. 43% of samples had increased FGFR1 copy number. No correlations between FGFR1 copy number gain and clinicopathological variables were observed. CONCLUSIONS: We identified c-MYC copy number gain as a prognostic marker for TNBC. Our results indicate that c- MYC may contribute to TNBC progression. We observed no significant association between c-MYC and/or FGFR1 copy number status and patient survival.