Cancer

Lgr5 was identified as a promising gastrointestinal tract stem cell marker in mice. Lineage tracing indicates that Lgr5(+) cells may not only be the cells responsible for the origin of tumors; they may also be the so-called cancer stem cells. In the present study, we investigated the presence of Lgr5(+) cells and their biological significance in normal human gastric mucosa and gastric tumors. RNAscope, a newly developed RNA in situ hybridization technique, specifically labeled Lgr5(+) cells at the basal glands of the gastric antrum.

BACKGROUND:

Current approaches for detecting circulating tumour cells (CTCs) in blood are dependent on CTC enrichment and are based either on surface epithelial markers on CTCs or on cell size differences. The objectives of this study were to develop and characterise an ultrasensitive multiplex fluorescent RNA in situ hybridisation (ISH)-based CTC detection system called CTCscope. This method detects a multitude of tumour-specific markers at single-cell level in blood.

METHODS:

PURPOSE:

Quantification of mRNA has historically been done by reverse transcription polymerase chain reaction (RT-PCR). Recently, a robust method of detection of mRNA utilizing in situ hybridization has been described that is linear and shows high specificity with low background. Here we describe the use of the AQUA method of quantitative immunofluorescence (QIF) for measuring mRNA in situ using ESR1 (the estrogen receptor alpha gene) in breast cancer to determine its predictive value compared to Estrogen Receptor α (ER) protein.

METHODS:

OBJECTIVE:

Wnt/Tcf, Lgr5, Ascl2 and/or Bmi1 signalling is believed to define the mouse intestinal stem cell niche(s) from which adenomas arise. The aim of this study was to determine the relevance of these putative intestinal stem cell markers to human colorectal cancer.

DESIGN:

Estrogen receptor-alpha (ERα) is an important biomarker used to classify and direct therapy decisions in breast cancer (BC). Both ERα protein and its transcript, ESR1, are used to predict response to tamoxifen therapy, yet certain tumors have discordant levels of ERα protein and ESR1, which is currently unexplained. Cellular ERα protein levels can be controlled post-translationally by the ubiquitin-proteasome pathway through a mechanism that depends on phosphorylation at residue S118.

Oropharyngeal squamous cell carcinoma (SCC) is strongly associated with human papillomavirus (HPV) infection, which is distinctively different from most other head and neck cancers. However, a robust quantitative reverse transcription PCR (RT-qPCR) method for comprehensive expression profiling of HPV genes in routinely fixed tissues has not been reported. To address this issue, we have established a new real-time RT-PCR method for the expression profiling of the E6 and E7 oncogenes from 13 high-risk HPV types.

The stomach is innervated by the vagal nerve. Several studies have demonstrated that the vagal nerve has a trophic effect on the rat oxyntic mucosa and that the trophic effect of hypergastrinemia is dependent on intact vagal innervation. The effect of vagal denervation on gastric carcinogenesis has been examined in Mastomys natalensis and hypergastrinemic transgenic INS-GAS mice, with no effect of unilateral vagotomy in Mastomys but an anti-carcinogenic effect in INS-GAS mice.

In a recent study, a unique gene expression signature was observed when comparing esophageal squamous cell carcinoma (ESCC) epithelial cells to normal esophageal epithelial cells using laser capture microdissection (LCM) and cDNA microarray technology. To validate the expression of several intriguing genes from that study (KRT17, cornulin, CD44, and EpCAM), we employed two new technologies, expression microdissection (xMD) for high-throughput microdissection facilitating protein analysis and RNAscope for the evaluation of low abundant transcripts in situ.

Detecting human papillomavirus (HPV) infection in head and neck squamous cell carcinoma (HNSCC) is clinically relevant, but there is no agreement about the most appropriate methodology. We have studied 64 oropharyngeal carcinomas using p16 immunohistochemistry, HPV DNA in situ hybridisation (ISH) and HPV DNA polymerase chain reaction (PCR) followed by pyrosequencing. We have also evaluated a new assay, RNAscope, designed to detect HPV E6/E7 RNA transcripts. Using a threshold of 70 % labelled tumour cells, 21 cases (32.8 %) were p16 positive.

Targeted therapies have opened new perspectives in clinical oncology. However, clinicians have observed a lack of response in a relevant percentage of patients and frequent relapse in patients who initially respond. Therefore, a compelling challenge is to identify mechanisms underlying resistance and strategies to circumvent these hurdles. A growing body of evidence indicates that MET, the tyrosine kinase receptor for hepatocyte growth factor (HGF), is frequently implicated in resistance to targeted therapies.