Genetic interaction between Tmprss2-ERG gene fusion and Nkx3.1-loss does not enhance prostate tumorigenesis in mouse models

Function and regulation of the PEA3 subfamily of ETS transcription factors in cancer

The PEA3 subfamily is a subgroup of the E26 transformation-specific (ETS) family. Its members, ETV1, ETV4, and ETV5, have been found to be overexpressed in multiple cancers. The deregulation of ETV1, ETV4, and ETV5 induces cell growth, invasion, and migration in various tumor cells, leading to tumor progression, metastasis, and drug resistance. Therefore, exploring drugs or therapeutic targets that target the PEA3 subfamily may contribute to the clinical treatment of tumor patients. In this review, we introduce the structures and functions of the PEA3 subfamily members, systematically review their main roles in various tumor cells, analyze their prognostic and diagnostic value, and, finally, introduce several molecular targets and therapeutic drugs targeting ETV1, ETV4, and ETV5. We conclude that targeting a series of upstream regulators and downstream target genes of the PEA3 subfamily may be an effective strategy for the treatment of ETV1/ETV4/ETV5-overexpressing tumors.

Genetically Engineered Mouse Models of Prostate Cancer in the Postgenomic Era

Recent genomic sequencing analyses have unveiled the spectrum of genomic alterations that occur in primary and advanced prostate cancer, raising the question of whether the corresponding genes are functionally relevant for prostate tumorigenesis, and whether such functions are associated with particular disease stages. In this review, we describe genetically engineered mouse models (GEMMs) of prostate cancer, focusing on those that model genomic alterations known to occur in human prostate cancer. We consider whether the phenotypes of GEMMs based on gain or loss of function of the relevant genes provide reliable counterparts to study the predicted consequences of the corresponding genomic alterations as occur in human prostate cancer, and we discuss exceptions in which the GEMMs do not fully emulate the expected phenotypes. Last, we highlight future directions for the generation of new GEMMs of prostate cancer and consider how we can use GEMMs most effectively to decipher the biological and molecular mechanisms of disease progression, as well as to tackle clinically relevant questions.

Genetics and biology of prostate cancer

Despite the high long-term survival in localized prostate cancer, metastatic prostate cancer remains largely incurable even after intensive multimodal therapy. The lethality of advanced disease is driven by the lack of therapeutic regimens capable of generating durable responses in the setting of extreme tumor heterogeneity on the genetic and cell biological levels. Here, we review available prostate cancer model systems, the prostate cancer genome atlas, cellular and functional heterogeneity in the tumor microenvironment, tumor-intrinsic and tumor-extrinsic mechanisms underlying therapeutic resistance, and technological advances focused on disease detection and management. These advances, along with an improved understanding of the adaptive responses to conventional cancer therapies, anti-androgen therapy, and immunotherapy, are catalyzing development of more effective therapeutic strategies for advanced disease. In particular, knowledge of the heterotypic interactions between and coevolution of cancer and host cells in the tumor microenvironment has illuminated novel therapeutic combinations with a strong potential for more durable therapeutic responses and eventual cures for advanced disease. Improved disease management will also benefit from artificial intelligence-based expert decision support systems for proper standard of care, prognostic determinant biomarkers to minimize overtreatment of localized disease, and new standards of care accelerated by next-generation adaptive clinical trials.

Protocols for Studies on TMPRSS2/ERG in Prostate Cancer

TMPRSS2/ERG is the most common type of gene fusions found in human prostate cancer. There are two important features of TMPRSS2/ERG fusions. One is that these gene fusions lead to ectopic expression of ERG, an ETS family transcription factor, in prostate epithelial cells from the 5' control region of an androgen/estrogen dual-responsive gene, TMPRSS2; the other is that ~60% of these fusions are generated via intrachromosomal deletion of the interstitial region between TMPRSS2 and ERG. To recapitulate these important aspects of TMPRSS2/ERG fusions, we generated several TMPRSS2/ERG knockin mouse models based on the endogenous Tmprss2 locus. We found that TMPRSS2/ERG represents an early event in prostate tumorigenesis, by sensitizing prostate cells for cooperation with other oncogenic events, such as PTEN-deficiency. We also found that the interstitial region between TMPRSS2 and ERG harbors at least one prostate tumor suppressor, ETS2, whose loss contributes to prostate cancer progression. In this protocol, we describe how these knockin mouse models can be utilized to study roles of TMPRSS2/ERG fusions in prostate cancer development both in vivo and in vitro.

Identification of four Indian ascidians based on COI gene sequences

DNA barcoding involving the sequencing of a short mitochondrial DNA segment, cytochrome c oxidase subunit 1 (COI) gene, is a specialized technique for the identification of species even at the early embryonic and larval stages, which is quite difficult in morphology-based taxonomy. Ascidians are sessile invertebrate chordates possessing numerous biochemical as well as pharmacological activities. In this study, a total of 36 ascidian samples belonging to the family Didemnidae were sequenced for a 650 bp region of the mitochondrial COI gene. All the species were represented by multiple specimens. The barcode sequences showed no stop-codons and indels in the alignments. The aligned sequences were submitted in Barcode submission tool, NCBI, and the accession numbers were obtained. The minimum intraspecific distance was found to be 0.00% and the maximum was 2.23%. Mean Kimura 2-parameter (K2P) distances within-species, genus, and family were 0.88, 5.98, and 20.03%, respectively. The mean interspecific distance is more than the mean intraspecific divergence, which indicates efficiency of DNA barcoding for identification of ascidians.