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result(s) for
"Ramnarine, Varune Rohan"
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Metagenomic and metatranscriptomic analysis of human prostate microbiota from patients with prostate cancer
by
Ramnarine, Varune Rohan
,
Feng, Ye
,
Ren, Shancheng
in
Animal Genetics and Genomics
,
Benign
,
Biodiversity
2019
Background
Prostate cancer (PCa) is the most common malignant neoplasm among men in many countries. Since most precancerous and cancerous tissues show signs of inflammation, chronic bacterial prostatitis has been hypothesized to be a possible etiology. However, establishing a causal relationship between microbial inflammation and PCa requires a comprehensive analysis of the prostate microbiome. The aim of this study was to characterize the microbiome in prostate tissue of PCa patients and investigate its association with tumour clinical characteristics as well as host expression profiles.
Results
The metagenome and metatranscriptome of tumour and the adjacent benign tissues were assessed in 65 Chinese radical prostatectomy specimens.
Escherichia
,
Propionibacterium
,
Acinetobacter
and
Pseudomonas
were abundant in both metagenome and metatranscriptome, thus constituting the core of the prostate microbiome. The biodiversity of the microbiomes could not be differentiated between the matched tumour/benign specimens or between the tumour specimens of low and high Gleason Scores. The expression profile of ten
Pseudomonas
genes was strongly correlated with that of eight host small RNA genes; three of the RNA genes may negatively associate with metastasis. Few viruses could be identified from the prostate microbiomes.
Conclusions
This is the first study of the human prostate microbiome employing an integrated metagenomics and metatranscriptomics approach. In this Chinese cohort, both metagenome and metatranscriptome analyses showed a non-sterile microenvironment in the prostate of PCa patients, but we did not find links between the microbiome and local progression of PCa. However, the correlated expression of
Pseudomonas
genes and human small RNA genes may provide tantalizing preliminary evidence that
Pseudomonas
infection may impede metastasis.
Journal Article
Prognostic gene-expression signature of carcinoma-associated fibroblasts in non-small cell lung cancer
2011
The tumor microenvironment strongly influences cancer development, progression, and metastasis. The role of carcinoma-associated fibroblasts (CAFs) in these processes and their clinical impact has not been studied systematically in non-small cell lung carcinoma (NSCLC). We established primary cultures of CAFs and matched normal fibroblasts (NFs) from 15 resected NSCLC. We demonstrate that CAFs have greater ability than NFs to enhance the tumorigenicity of lung cancer cell lines. Microarray gene-expression analysis of the 15 matched CAF and NF cell lines identified 46 differentially expressed genes, encoding for proteins that are significantly enriched for extracellular proteins regulated by the TGF-β signaling pathway. We have identified a subset of 11 genes (13 probe sets) that formed a prognostic gene-expression signature, which was validated in multiple independent NSCLC microarray datasets. Functional annotation using protein-protein interaction analyses of these and published cancer stroma-associated gene-expression changes revealed prominent involvement of the focal adhesion and MAPK signaling pathways. Fourteen (30%) of the 46 genes also were differentially expressed in laser-capture-microdissected corresponding primary tumor stroma compared with the matched normal lung. Six of these 14 genes could be induced by TGF-β1 in NF. The results establish the prognostic impact of CAF-associated gene-expression changes in NSCLC patients.
Journal Article
The long non-coding RNA PCGEM1 is regulated by androgen receptor activity in vivo
2015
Background
Long non-coding RNAs (lncRNAs) can orchestrate oncogenic or tumor-suppressive functions in cancer biology. Accordingly,
PCGEM1
and
PRNCR1
were implicated in progression of prostate cancer (PCa) as transcriptional co-regulators of the androgen receptor (AR). However, these findings were recently refuted asserting that neither gene physically binds to the AR. Despite evidence for differing AR transcriptional programs
in vivo
and
in vitro
, studies investigating AR-regulation of these genes hitherto have only been conducted
in vitro
. Here, we further examine the relevance of
PCGEM1
and
PRNCR1
in PCa, and their relationship with AR signaling, using patient-derived xenograft models.
Findings
RNA sequencing of two distinct androgen-dependent models shows
PCGEM1
to be considerably expressed, while
PRNCR1
showed scant basal expression.
PCGEM1
was sharply down-regulated following castration and up-regulated upon AR activation
in vivo
. However, we found no parallel evidence following AR stimulation
in vitro
. A
PCGEM1
-associated gene expression signature (PES) was significantly repressed in response to androgen ablation therapy and in hormone-refractory versus hormone-naïve PCa patients. Furthermore, we found
PCGEM1
was uniformly distributed in PCa cell nucleus and cytoplasm which remained unaltered upon AR transcriptional activation.
PCGEM1
was up-regulated in primary PCa but not in metastasized PCa. Accordingly, the PES was significantly down-regulated in advanced and higher grade PCa patients from multiple independent studies.
Conclusion
Our results demonstrate
PCGEM1
as an
in vivo
androgen-regulated transcript with potential nuclear and/or cytoplasmic function(s). Importantly, the clinical expression profile of
PCGEM1
implicates it in the early stages of PCa warranting further research in this direction.
Journal Article
Protease nexin 1 inhibits hedgehog signaling in prostate adenocarcinoma
by
Mallof, Chad
,
Beech, John
,
Hamdy, Freddie
in
Adenocarcinoma
,
Adenocarcinoma - genetics
,
Adenocarcinoma - metabolism
2012
Prostate adenocarcinoma (CaP) patients are classified into low-, intermediate-, and high-risk groups that reflect relative survival categories. While there are accepted treatment regimens for low- and high-risk patients, intermediate-risk patients pose a clinical dilemma, as treatment outcomes are highly variable for these individuals. A better understanding of the factors that regulate the progression of CaP is required to delineate risk. For example, aberrant activation of the Hedgehog (Hh) pathway is implicated in CaP progression. Here, we identify the serine protease inhibitor protease nexin 1 (PN1) as a negative regulator of Hh signaling in prostate. Using human CaP cell lines and a mouse xenograft model of CaP, we demonstrate that PN1 regulates Hh signaling by decreasing protein levels of the Hh ligand Sonic (SHH) and its downstream effectors. Furthermore, we show that SHH expression enhanced tumor growth while overexpression of PN1 inhibited tumor growth and angiogenesis in mice. Finally, using comparative genome hybridization, we found that genetic alterations in Hh pathway genes correlated with worse clinical outcomes in intermediate-risk CaP patients, indicating the importance of this pathway in CaP.
Journal Article
Protease nexin 1 inhibits Hedgehog signaling in prostate adenocarcinoma
by
Mallof, Chad
,
Beech, John
,
Hamdy, Freddie
in
Adenocarcinoma
,
Care and treatment
,
Cellular signal transduction
2012
Prostate adenocarcinoma (CaP) patients are classified into low-, intermediate-, and high-risk groups that reflect relative survival categories. While there are accepted treatment regimens for low- and high-risk patients, intermediate-risk patients pose a clinical dilemma, as treatment outcomes are highly variable for these individuals. A better understanding of the factors that regulate the progression of CaP is required to delineate risk. For example, aberrant activation of the Hedgehog (Hh) pathway is implicated in CaP progression. Here, we identify the serine protease inhibitor protease nexin 1 (PN1) as a negative regulator of Hh signaling in prostate. Using human CaP cell lines and a mouse xenograft model of CaP, we demonstrate that PN1 regulates Hh signaling by decreasing protein levels of the Hh ligand Sonic (SHH) and its downstream effectors. Further-more, we show that SHH expression enhanced tumor growth while overexpression of PN1 inhibited tumor growth and angiogenesis in mice. Finally, using comparative genome hybridization, we found that genetic alterations in Hh pathway genes correlated with worse clinical outcomes in intermediate-risk CaP patients, indicating the importance of this pathway in CaP.
Journal Article