Eficacia de la combinación de Vinorelbine- Trastuzumab en carcinoma de mama metastásico con sobreexpresión de HER2, previamente tratado con Trastuzumab

L'addició de Trastuzumab a quimioteràpia basada en taxans millora la supervivència de les pacients amb carcinoma de mama metastàtic i sobreexpressió de HER2. En el nostre estudi, analitzem l'eficàcia de Vinorelbine-Trastuzumab a la progressió a Trastuzumab. De les 46 pacients analitzades, 26 van realitzar Trastuzumab previ al tractament amb Vinorelbine-Trastuzumab, obtenint un temps lliure de progressió de 6.5 mesos, benefici clínic del 48% i respostes del 27%, similar al descrit pels tractaments aprovats, Capecitabina-Lapatinib i Capecitabina-Trastuzumab. CONCLUSIÓ: Vinorelbine-Trastuzumab en pacients prèviament tractades amb Trastuzumab manté una significativa activitat en càncer de mama metastàtic en progressió a Trastuzumab.

Implicación del fenotipo de cáncer de mama en pacientes con carcinomatosis leptomeníngea.

Aquest estudi permet conèixer les implicacions dels diferents subtipus de cáncer de mama: luminal A, luminal B, HER2+, triple negatiu en el desenvolupament y pronostic de la carcinomatosi leptomeníngea (CL). Es van identificar 38 pacients, major proporció: luminal B y HER2+, 53% va rebre quimioteràpia sistémica (QTS). La mitjana de supervivencia post CL: 2,6 messos. A l’anàlisis univariat: ECOG de 0-2 y tractament amb QT van ser variables pronòstiques i al multivariant nomès QTS. En conclussió el subtipus de cáncer de mama influiex en el temps d’aparició de la CL, no afectant la supervivencia desprès del diagnóstic.

Dual activation of pathways regulated by steroid receptors and peptide growth factors in primary prostate cancer revealed by Factor Analysis of microarray data

Background: We use an approach based on Factor Analysis to analyze datasets generated for transcriptional profiling. The method groups samples into biologically relevant categories, and enables the identification of genes and pathways most significantly associated to each phenotypic group, while allowing for the participation of a given gene in more than one cluster. Genes assigned to each cluster are used for the detection of pathways predominantly activated in that cluster by finding statistically significant associated GO terms. We tested the approach with a published dataset of microarray experiments in yeast. Upon validation with the yeast dataset, we applied the technique to a prostate cancer dataset. Results: Two major pathways are shown to be activated in organ-confined, non-metastatic prostate cancer: those regulated by the androgen receptor and by receptor tyrosine kinases. A number of gene markers (HER3, IQGAP2 and POR1) highlighted by the software and related to the later pathway have been validated experimentally a posteriori on independent samples. Conclusion: Using a new microarray analysis tool followed by a posteriori experimental validation of the results, we have confirmed several putative markers of malignancy associated with peptide growth factor signalling in prostate cancer and revealed others, most notably ERRB3 (HER3). Our study suggest that, in primary prostate cancer, HER3, together or not with HER4, rather than in receptor complexes involving HER2, could play an important role in the biology of these tumors. These results provide new evidence for the role of receptor tyrosine kinases in the establishment and progression of prostate cancer.

Identification of molecular subtypes and gene expression patterns of breast cancer analysing RNA-seq data

Breast cancer is the most common diagnosed cancer and the leading cause of cancer death among females worldwide. It is considered a highly heterogeneous disease and it must be classified into more homogeneous groups. Hence, the purpose of this study was to classify breast tumors based on variations in gene expression patterns derived from RNA sequencing by using different class discovery methods. 42 breast tumors paired-samples were sequenced by Illumine Genome Analyzer and the data was analyzed and prepared by TopHat2 and htseq-count. As reported previously, breast cancer could be grouped into five main groups known as basal epithelial-like group, HER2 group, normal breast-like group and two Luminal groups with a distinctive expression profile. Classifying breast tumor samples by using PAM50 method, the most common subtype was Luminal B and was significantly associated with ESR1 and ERBB2 high expression. Luminal A subtype had ESR1 and SLC39A6 significant high expression, whereas HER2 subtype had a high expression of ERBB2 and CNNE1 genes and low luminal epithelial gene expression. Basal-like and normal-like subtypes were associated with low expression of ESR1, PgR and HER2, and had significant high expression of cytokeratins 5 and 17. Our results were similar compared with TGCA breast cancer data results and with known studies related with breast cancer classification. Classifying breast tumors could add significant prognostic and predictive information to standard parameters, and moreover, identify marker genes for each subtype to find a better therapy for patients with breast cancer.

Green tea catechin inhibits fatty acid synthase without stimulating carnitine Palmitoyltransferase-1 or inducing weight loss in experimental animals

Background: The enzyme fatty acid synthase (FASN) is highly expressed in many human carcinomas and its inhibition is cytotoxic to human cancer cells. The use of FASN inhibitors has been limited until now by anorexia and weight loss, which is associated with the stimulation of fatty acid oxidation. Materials and Methods: The in vitro effect of (-)-epigallocatechin-3-gallate (EGCG) on fatty acid metabolism enzymes, on apoptosis and on cell signalling was evaluated. In vivo, the effect of EGCG on animal body weight was addressed. Results: EGCG inhibited FASN activity, induced apoptosis and caused a marked decrease of human epidermal growth factor receptor 2 (HER2), phosphatidylinositol 3-kinase (PI3K)/AKT and extracellular (signal)-regulated kinase (ERK) 1/2 proteins, in breast cancer cells. EGCG did not induce a stimulatory effect on CPT-1 activity in vitro (84% of control), or on animal body weight in vivo (99% of control). Conclusion: EGCG is a FASN inhibitor with anticancer activity which does not exhibit cross-activation of fatty acid oxidation and does not induce weight loss, suggesting its potential use as an anticancer drug.