Monday, October 26, 2009

Pten in stromal fibroblasts suppresses mammary epithelial tumours. Nature. 2009 Oct 22;461(7267):1084-91.




Trimboli AJ, Cantemir-Stone CZ, Li F, Wallace JA, Merchant A, Creasap N, Thompson JC, Caserta E, Wang H, Chong JL, Naidu S, Wei G, Sharma SM, Stephens JA, Fernandez SA, Gurcan MN, Weinstein MB, Barsky SH, Yee L, Rosol TJ, Stromberg PC, Robinson ML, Pepin F, Hallett M, Park M, Ostrowski MC, Leone G.
Tumor Microenvironment Program, Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA



The tumour stroma is believed to contribute to some of the most malignant characteristics of epithelial tumours. However, signalling between stromal and tumour cells is complex and remains poorly understood. Here we show that the genetic inactivation of Pten in stromal fibroblasts of mouse mammary glands accelerated the initiation, progression and malignant transformation of mammary epithelial tumours. This was associated with the massive remodelling of the extracellular matrix (ECM), innate immune cell infiltration and increased angiogenesis. Loss of Pten in stromal fibroblasts led to increased expression, phosphorylation (T72) and recruitment of Ets2 to target promoters known to be involved in these processes. Remarkably, Ets2 inactivation in Pten stroma-deleted tumours ameliorated disruption of the tumour microenvironment and was sufficient to decrease tumour growth and progression. Global gene expression profiling of mammary stromal cells identified a Pten-specific signature that was highly represented in the tumour stroma of patients with breast cancer. These findings identify the Pten-Ets2 axis as a critical stroma-specific signalling pathway that suppresses mammary epithelial tumours.




Resto de las Figuras (Libre acceso)
http://www.nature.com/nature/journal/v461/n7267/fig_tab/nature08486_ft.html

Tuesday, October 20, 2009

Distinct inherited metastasis susceptibility exists for different breast cancer subtypes: a prognosis study


Szu-Min Hsieh email, Maxime P Look email, Anieta M Sieuwerts email, John A Foekens email and Kent W Hunter email

Breast Cancer Research 2009, 11:R75doi:10.1186/bcr2412


Published: 13 October 2009

Abstract (provisional)

Introduction

Previous studies in mouse models and pilot epidemiology studies have demonstrated that inherited polymorphisms are associated with inherited risk of tumor progression and poor outcome in human breast cancer. To extend these studies and gain better understanding of the function of inherited polymorphism in breast cancer progression a validation prognosis study was performed in a large independent breast cancer patient population.

Methods

The study population consisted of 1863 Dutch patients with operable primary breast cancer from Rotterdam, The Netherlands. Genomic DNA was genotyped for the missense Pro436Leu RRP1B single nucleotide polymorphism (SNP) rs9306160 and the intronic SIPA1 SNP rs2448490 by SNP-specific PCR.

Results

A significant association of variants in RRP1B with metastasis-free survival was observed (P = 0.012), validating the role of RRP1B with inherited metastatic susceptibility. Stratification of patients revealed that association with patients' survival was found to be specifically restricted to estrogen receptor positive, lymph node-negative (ER+/LN-) patients (P = 0.011). The specific association with metastasis-free survival only in ER+/LN- patients was replicated for SIPA1, a second metastasis susceptibility gene known to physically interact with RRP1B (P = 0.006). Combining the genotypes of these two genes resulted in the significant ability to discriminate patients with poor metastasis-free survival (HR: 0.40, 95% CI: 0.24 to 0.68, P = 0.001).

Conclusions

These results validate SIPA1 and RRP1B as metastasis susceptibility genes and suggest that genotyping assays may be a useful supplement to other clinical and molecular indicators of prognosis. The results also suggest that lymphatic and hematogeneous metastases are genetically distinct that may involve different mechanisms. If true, these results suggest that metastatic disease, like primary breast cancer, may be multiple diseases and that stratification of late stage patients may therefore be required to fully understand breast cancer progression and metastasis.

Tuesday, October 06, 2009

IgG nobel prizes awarded

On October 1, the 2009 IgNobel awards were handed out at Harvard University. The winners:

VETERINARY MEDICINE PRIZE: Catherine Douglas and Peter Rowlinson of Newcastle University, Newcastle-Upon-Tyne, UK, for showing that cows who have names give more milk than cows that are nameless.

PEACE PRIZE: Stephan Bolliger, Steffen Ross, Lars Oesterhelweg, Michael Thali and Beat Kneubuehl of the University of Bern, Switzerland, for determining — by experiment — whether it is better to be smashed over the head with a full bottle of beer or with an empty bottle.

ECONOMICS PRIZE: The directors, executives, and auditors of four Icelandic banks — Kaupthing Bank, Landsbanki, Glitnir Bank, and Central Bank of Iceland — for demonstrating that tiny banks can be rapidly transformed into huge banks, and vice versa — and for demonstrating that similar things can be done to an entire national economy.

CHEMISTRY PRIZE: Javier Morales, Miguel Apátiga, and Victor M. Castaño of Universidad Nacional Autónoma de México, for creating diamonds from liquid — specifically from tequila.

MEDICINE PRIZE: Donald L. Unger, of Thousand Oaks, California, USA, for investigating a possible cause of arthritis of the fingers, by diligently cracking the knuckles of his left hand — but never cracking the knuckles of his right hand — every day for more than sixty (60) years.

PHYSICS PRIZE: Katherine K. Whitcome of the University of Cincinnati, USA, Daniel E. Lieberman of Harvard University, USA, and Liza J. Shapiro of the University of Texas, USA, for analytically determining why pregnant women don't tip over.

LITERATURE PRIZE: Ireland's police service (An Garda Siochana), for writing and presenting more than fifty traffic tickets to the most frequent driving offender in the country — Prawo Jazdy — whose name in Polish means "Driving License".

PUBLIC HEALTH PRIZE: Elena N. Bodnar, Raphael C. Lee, and Sandra Marijan of Chicago, Illinois, USA, for inventing a brassiere that, in an emergency, can be quickly converted into a pair of protective face masks, one for the brassiere wearer and one to be given to some needy bystander.

MATHEMATICS PRIZE: Gideon Gono, governor of Zimbabwe’s Reserve Bank, for giving people a simple, everyday way to cope with a wide range of numbers — from very small to very big — by having his bank print bank notes with denominations ranging from one cent ($.01) to one hundred trillion dollars ($100,000,000,000,000).

BIOLOGY PRIZE: Fumiaki Taguchi, Song Guofu, and Zhang Guanglei of Kitasato University Graduate School of Medical Sciences in Sagamihara, Japan, for demonstrating that kitchen refuse can be reduced more than 90% in mass by using bacteria extracted from the feces of giant pandas.

An interesting and entertaining crop as always. Links to papers and other information can be found here.

Monday, October 05, 2009

´Técnica para identificar mRNAs que se traducen versus mRNA aquellos que no se están traduciendo.

*

4E-BP Extends Lifespan upon Dietary Restriction by Enhancing Mitochondrial Activity in Drosophila. Cell, Volume 139, Issue 1, 149-160, 2 October 2009. Zid et al.


En este paper utilizan un sistema para separar mRNAs que se están traduciendo activamente versus aquellos mRNAs que se traducen poco y aquellos que se no están traduciendo (esto mediante gradientes asumiendo que los muy activos tienen muchos ribosomas versus aquellos no activos carecen de ribosomas) después hicieron microarreglos de expresión. (Los cuales muy probablemente reflejan mejor cambios en el proteoma que aquellos inferidos mediante microarreglos donde se usa "mRNA TOTAL"..) Ergo sería interesante hacer algunos de los microarreglos que se hacen en labo usando esta técnica y ver las diferencias.

*La figura muestra en el gradiente a los mRNA sin polisomas y hasta el fondo aquellos mRNAs con múltiples polisomas.