Probes for INS

Spermatogonial stem cells (SSCs) fuel the production of male germ cells but the mechanisms behind SSC self-renewal, proliferation, and differentiation are still poorly understood. Using the Wnt target gene Axin2 and genetic lineage-tracing experiments, we found that undifferentiated spermatogonia, comprising SSCs and transit amplifying progenitor cells, respond to Wnt/β-catenin signals. Genetic elimination of β-catenin indicates that Wnt/β-catenin signaling promotes the proliferation of these cells. Signaling is likely initiated by Wnt6, which is uniquely expressed by neighboring Sertoli cells, the only somatic cells in the seminiferous tubule that support germ cells and act as a niche for SSCs. Therefore, unlike other stem cell systems where Wnt/β-catenin signaling is implicated in self-renewal, the Wnt pathway in the testis specifically contributes to the proliferation of SSCs and progenitor cells.

Abstract

Abstract

PURPOSE:

Understanding tumour heterogeneity is an important challenge in current cancer research. Transcription and epigenetic profiling of cultured melanoma cells have defined at least two distinct cell phenotypes characterised by distinctive gene expression signatures associated with high or low/absent expression of Microphthalmia-associated transcription factor (MITF). Nevertheless, heterogeneity of cellpopulations and gene expression in primary human tumours is much less well characterised.

EXPERIMENTAL DESIGN:

We performed single cell gene expression analyses on 472 cells isolated from needle biopsies of 5 primary human melanomas, 4 superficial spreading and one acral melanoma. The expression of MITF-high and MITF-low signature genes was assessed and compared to investigate intra and inter-tumoural heterogeneity and correlated gene expression profiles.

RESULTS:

Single cell gene expression analyses revealed varying degrees of intra and inter-tumour heterogeneity conferred by the variable expression of distinct sets of genes in different tumours. Expression of MITF partially correlated with that of its known target genes while SOX10 expression correlated best with PAX3 and ZEB2. Nevertheless, cells simultaneously expressing MITF-high and MITF-low signature genes were observed both by single cell analyses and RNAscope.

CONCLUSIONS:

Single cell analyses can be performed on limiting numbers of cells from primary human melanomas revealing their heterogeneity. While tumours comprised variable proportions of cells with the MITF-high and MITF-low gene expression signatures characteristic of melanoma cultures, primary tumours also comprised cells expressing markers of both signatures defining a novel cell state in tumours in vivo.

Abstract

BACKGROUND:

Large animal models, such as the dog, are increasingly being used for studying diseases including gastrointestinal (GI) disorders. Dogs share similar environmental, genomic, anatomical, and intestinal physiologic features with humans. To bridge the gap between commonly used animal models, such as rodents, and humans, and expand the translational potential of the dog model, we developed a three-dimensional (3D) canine GI organoid (enteroid and colonoid) system. Organoids have recently gained interest in translational research as this model system better recapitulates the physiological and molecular features of the tissue environment in comparison with two-dimensional cultures.

RESULTS:

Organoids were derived from tissue of more than 40 healthy dogs and dogs with GI conditions, including inflammatory bowel disease (IBD) and intestinal carcinomas. Adult intestinal stem cells (ISC) were isolated from whole jejunal tissue as well as endoscopically obtained duodenal, ileal, and colonic biopsy samples using an optimized culture protocol. Intestinal organoids were comprehensively characterized using histology, immunohistochemistry, RNA in situ hybridization, and transmission electron microscopy, to determine the extent to which they recapitulated the in vivo tissue characteristics. Physiological relevance of the enteroid system was defined using functional assays such as optical metabolic imaging (OMI), the cystic fibrosis transmembrane conductance regulator (CFTR) function assay, and Exosome-Like Vesicles (EV) uptake assay, as a basis for wider applications of this technology in basic, preclinical and translational GI research. We have furthermore created a collection of cryopreserved organoids to facilitate future research.

CONCLUSIONS:

We establish the canine GI organoid systems as a model to study naturally occurring intestinal diseases in dogs and humans, and that can be used for toxicology studies, for analysis of host-pathogen interactions, and for other translational applications.

HPV-related and HPV-unrelated oropharyngeal squamous cell carcinomas are two distinct entities according to the Union for International Cancer Control, with a better prognosis conferred to HPV-related oropharyngeal squamous cell carcinomas. However, variable clinical outcomes are observed among patients with p16 positive oropharyngeal squamous cell carcinoma, which is a surrogate marker of HPV infection. We aimed to investigate the prognostic value of RNA CISH against E6 and E7 transcripts (HPV RNA CISH) to predict such variability. We retrospectively included 50 histologically confirmed p16 positive oropharyngeal squamous cell carcinomas (p16 positive immunostaining was defined by a strong staining in 70% or more of tumor cells). HPV RNA CISH staining was assessed semi-quantitatively to define two scores: RNA CISH “low” and RNA CISH “high”. Negative HPV RNA CISH cases were scored as RNA CISH “low”. This series contained 29 RNA CISH low cases (58%) and 21 RNA CISH high cases (42%). Clinical and pathologic baseline characteristics were similar between the two groups. RNA CISH high staining was associated with a better overall survival in both univariate and multivariate analyses (p = 0.033 and p = 0.042, respectively). Other recorded parameters had no prognostic value. In conclusion, HPV RNA CISH might be an independent prognostic marker in p16 positive oropharyngeal squamous cell carcinomas and might help guide therapeutics.

Abstract

Background

Accurate identification of HPV-driven oropharyngeal cancer (OPC) is a major issue and none of the current diagnostic approaches is ideal. An in situ hybridization (ISH) assay that detects high-risk HPV E6/E7 mRNA, called the RNAscope HPV-test, has been recently developed. Studies have suggested that this assay may become a standard to define HPV-status.

Methods

To further assess this test, we compared its performance against the strategies that are used in routine clinical practice: p16 immunohistochemistry (IHC) as a single test and algorithms combining p16-IHC with HPV-DNA identification by PCR (algorithm-1) or ISH (algorithm-2).

Results

105 OPC specimens were analyzed. The prevalence of HPV-positive samples varied considerably: 67% for p16-IHC, 54% for algorithm-1, 61% for algorithm-2 and 59% for the RNAscope HPV-test. Discrepancies between the RNAscope HPV-test and p16-IHC, algorithm-1 and 2 were noted in respectively 13.3%, 13.1%, and 8.6%.

The 4 diagnostic strategies were able to identify 2 groups with different prognosis according to HPV-status, as expected. However, the greater survival differential was observed with the RNAscope HPV-test [HR: 0.19, 95% confidence interval (CI), 0.07–0.51, p = 0.001] closely followed by algorithm-1 (HR: 0.23, 95% CI, 0.08–0.66, p = 0.006) and algorithm-2 (HR: 0.26, 95% CI, 0.1–0.65, p = 0.004). In contrast, a weaker association was found when p16-IHC was used as a single test (HR: 0.33, 95% CI, 0.13–0.81, p = 0.02).

Conclusions

Our findings suggest that the RNAscope HPV-test and p16-based algorithms perform better that p16 alone to identify OPC that are truly driven by HPV-infection. The RNAscope HPV-test has the advantage of being a single test.

Abstract

BACKGROUND:

There is increasing evidence that high-risk human papillomavirus plays significant role in oropharyngeal cancer; however, there is lack of knowledge on the interplay between the virus and its downstream related molecules and their possible prognostic values. The objectives of the study are to better understand the interplay of the HR-HPV and its associated downstream molecules and to evaluate potential biomarkers for patient outcomes.

METHODS:

We conducted a retrospective study with available formalin-fixed, paraffin-embedded tissue from 244 oropharyngeal cancer patients that received curative radiotherapy or concurrent chemoradiotherapy from 2000 to 2008. In addition to chart review, we performed HPV DNA and RNA in situ hybridization and immunohistochemistry for p53, the retinoblastoma protein, p16, and cyclin D1 analysis. Cox-proportional hazard and Kaplan-Meier survival analysis were used to determine the prognostic markers for clinical outcomes.

RESULTS:

Patients averaged 57.3±9.4 year-old and were mostly males (76.2%) and ever-smokers (76.2%). All patients received curative radiotherapy and 44.3% received concurrent chemoradiotherapy. We detected the human papillomavirus in 77.9% of study patients. Ever-smokers, more advanced tumor stage, and receiving radiotherapy only had poorer 5-year overall survival, disease-specific survival, and loco-regional recurrence. Cases with positive human papillomavirus and p53 overexpression had poorer disease-specific survival. Cases without human papillomavirus, but cyclin D1 overexpression, was associated with poorer 5-year overall survival.

CONCLUSIONS:

Our data suggests that additional p53 and cyclin D1 testing may benefit oropharyngeal cancer patients with known human papillomavirus status.