In situ protein expression of RRM1, ERCC1, and BRCA1 in metastatic breast cancer patients treated with gemcitabine-based chemotherapy.

Ribonucleotide reductase 1 (RRM1) is a determinant of gemcitabine efficacy in non-small-cell lung cancer and pancreatic cancer. We investigated the protein levels of RRM1 and two other DNA repair enzymes, ERCC1 and BRCA1, in 55 metastatic breast cancer (MBC) patients undergoing gemcitabine-based chemotherapy. With automated in situ protein quantification (AQUA v1.6), the average scores for RRM1, ERCC1, and BRCA1 ranged from 245.6-2774.1, 74.0-410.3, and 54.4-1833.1, respectively. They were significantly associated with each other (Spearman's rho > or = .36; p < or = .007). Given their pattern of distribution, RRM1 and BRCA1 are potentially suitable markers for clinical decision making in MBC.

Clinical significance of PTEN and p-Akt co-expression in HER2-positive metastatic breast cancer patients treated with trastuzumab-based therapies.

OBJECTIVE: The phosphatase and tensine homologue gene (PTEN) plays a crucial role in proliferation and survival of cancer cells by antagonizing the function of phosphatidylinositol 3'-kinase (PI3K), which, in turn, results in decreased Akt activity. We investigated the clinical impact of the expression of PTEN, p-Akt and PI3K in HER2-positive metastatic breast cancer (MBC) patients treated with trastuzumab-based therapies. METHODS: Seventy-three patients treated with trastuzumab-based therapies were included and followed prospectively. PTEN, p-Akt and PI3K expression was determined by immunohistochemistry. RESULTS: PTEN, p-Akt and PI3K resulted positive in 48%, 71% and 46.5% of patients, respectively. A significant correlation between PTEN and p-Akt (kappa 0.22, p = 0.03) and p-Akt and PI3K (kappa 0.20, p = 0.05) was observed. PTEN-positive patients had a progression-free survival (PFS) longer than PTEN-negative ones (p = 0.06). When grouped together, patients co-expressing PTEN and p-Akt had a statistically significant longer PFS as compared to the rest of patients (p = 0.01). At the multivariate analysis, PTEN and p-Akt co-expression was an independent predictor of lower risk of progression (hazard ratio 0.53, p = 0.05). CONCLUSION: In HER2-positive MBC, basal co-expression of PTEN and p-Akt might identify those patients who are more likely to benefit from trastuzumab-based therapies.

Deregulation of Aurora kinase gene expression in human testicular germ cell tumours.

The Aurora kinases regulate chromosome segregation and cytokinesis, and alterations in their expression associate with cell malignant transformation. In this study, we demonstrated by qRT-PCR analysis of 14 seminomas that Aurora-A mRNA was, with respect to control tissues, augmented in five of 14 tumour tissues by 2.17 +/- 0.30 fold (P < 0.05) and reduced in 9 to 0.38 +/- 0.10 (P < 0.01). Aurora-B mRNA was increased in 11 tumour tissues by 4.33 +/- 0.82 fold (P < 0.01) and reduced in 3 to 0.41 +/- 0.11 fold. Aurora-C mRNA was reduced to 0.20 +/- 0.32 fold (P < 0.01) in 13 seminomas and up-regulated in one case. Western blot experiments, performed on protein extracts of nine seminomas and six normal testes, showed an up-regulation of Aurora-B protein by 10.14 +/- 3.51 fold (P < 0.05), while Aurora-A protein was found increased in four seminomas by 2.16 +/- 0.43 (P < 0.05), unchanged in three and reduced in two tumour tissues. Aurora-C protein was increased by 9.2 +/- 2.90 fold (P < 0.05), suggesting that post-transcriptional mechanisms modulate its expression. In conclusion, we demonstrated that expression of Aurora kinases is deregulated in seminomas, suggesting that they may play a role in the progression of testicular cancers.