Mahadevan Raj Rajasekaran

Dr. Mahadevan Raj Rajasekaran

orcid

Research Focus & Metrics

Academic Career Length

26Years (2001-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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5 September 2020 in Cancers
Verified
Journal Article
Open access
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JMJiayan Ma
Jiayan Ma
AGAditi Gnanasekar
Aditi Gnanasekar
ALAbby Lee
Abby Lee
WLWei Tse Li
Wei Tse Li
MHMartin Haas
Martin Haas
WOWeg Ongkeko
Weg Ongkeko
Although 1 in 9 American men will receive a diagnosis of prostate cancer (PC), most men with this diagnosis will not die from it, as most PCs are indolent. However, there is a subset of patients in which the once-indolent PC becomes metastatic and eventually, fatal. In this study, we analyzed microbial compositions of intratumor bacteria in PC to determine the influence of the microbiome on metastatic growth. Using large-scale RNA-sequencing data and corresponding clinical data, we correlated the abundance of microbes to immune pathways and PC risk factors, identifying specific microbes that either significantly deter or contribute to cancer aggressiveness. Interestingly, most of the microbes we found appeared to play anti-tumor roles in PC. Since these anti-tumor microbes were overrepresented in tumor samples, we believe that microbes thrive in the tumor microenvironment, outcompete cancer cells, and directly mitigate tumor growth by recruiting immune cells. These include Listeria monocytogenes, Methylobacterium radiotolerans JCM 2831, Xanthomonas albilineans GPE PC73, and Bradyrhizobium japonicum, which are negatively correlated with Gleason score, Tumor-Node-Metastasis (TNM) stage, prostate-specific antigen (PSA) level, and Androgen Receptor (AR) expression, respectively. We also identified microbes that contribute to tumor growth and are positively correlated with genomic alterations, dysregulated immune-associated (IA) genes, and prostate cancer stem cells (PCSC) genes.

1 January 2021 in The World Journal of Men's Health
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Journal Article
Open access
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SKSoyeun Kim
Soyeun Kim
MCMin Chul Cho
Min Chul Cho
SCSung Yong Cho
Sung Yong Cho
HCHong Chung
Hong Chung
MRMahadevan Raj Rajasekaran
Mahadevan Raj Rajasekaran
Kim S, et al. World J Mens Health. 2021 Jan;39(1):48-64. https://doi.org/10.5534/wjmh.200007

6 May 2002 in Journal of Andrology
Verified
Journal Article
Closed access
MRMahadevan Raj Rajasekaran
Mahadevan Raj Rajasekaran
AKArmen Kasyan
Armen Kasyan
AJAmita Jain
Amita Jain
SKSae‐Woong Kim
Sae‐Woong Kim
MMManoj Monga
Manoj Monga

21 July 2021 in Cancers
Verified
Journal Article
Open access
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WLWei Tse Li
Wei Tse Li
AIAnjali Iyangar
Anjali Iyangar
RRRohan Reddy
Rohan Reddy
JCJaideep Chakladar
Jaideep Chakladar
VBValmik Bhargava
Valmik Bhargava
MRMahadevan Raj Rajasekaran
Mahadevan Raj Rajasekaran
The intra-tumor microbiome has recently been linked to epithelial–mesenchymal transition (EMT) in a number of cancers. However, the relationship between EMT and microbes in bladder cancer has not been explored. In this study, we profiled the abundance of individual microbe species in the tumor samples of over 400 muscle invasive bladder carcinoma (MIBC) patients. We then correlated microbe abundance to the expression of EMT-associated genes and genes in the extracellular matrix (ECM), which are key players in EMT. We discovered that a variety of microbes, including E. coli, butyrate-producing bacterium SM4/1, and a species of Oscillatoria, were associated with expression of classical EMT-associated genes, including E-cadherin, vimentin, SNAI2, SNAI3, and TWIST1. We also found significant correlations between microbial abundance and the expression of genes in the ECM, specifically collagens and elastin. Lastly, we found that a large number of microbes exhibiting significant correlations to EMT are also associated with clinical prognosis and outcomes. We further determined that the microbes we profiled were likely not environmental contaminants. In conclusion, we discovered that the intra-tumoral microbiome could potentially play a significant role in the regulation of EMT in MIBC.

Verified
Journal Article
Open access
PDF file
JCJaideep Chakladar
Jaideep Chakladar
NSNeil Shende
Neil Shende
WLWei Tse Li
Wei Tse Li
MRMahadevan Raj Rajasekaran
Mahadevan Raj Rajasekaran
ECEric Chang
Eric Chang
WOWeg Ongkeko
Weg Ongkeko
The COVID-19 pandemic is marked by a wide range of clinical disease courses, ranging from asymptomatic to deadly. There have been many studies seeking to explore the correlations between COVID-19 clinical outcomes and various clinical variables, including age, sex, race, underlying medical problems, and social habits. In particular, the relationship between smoking and COVID-19 outcome is controversial, with multiple conflicting reports in the current literature. In this study, we aim to analyze how smoking may affect the SARS-CoV-2 infection rate. We analyzed sequencing data from lung and oral epithelial samples obtained from The Cancer Genome Atlas (TCGA). We found that the receptor and transmembrane protease necessary for SARS-CoV-2 entry into host cells, ACE2 and TMPRSS2, respectively, were upregulated in smoking samples from both lung and oral epithelial tissue. We then explored the mechanistic hypothesis that smoking may upregulate ACE2 expression through the upregulation of the androgen pathway. ACE2 and TMPRSS2 upregulation were both correlated to androgen pathway enrichment and the specific upregulation of central pathway regulatory genes. These data provide a potential model for the increased susceptibility of smoking patients to COVID-19 and encourage further exploration into the androgen and tobacco upregulation of ACE2 to understand the potential clinical ramifications.

1 April 2004 in International Journal Of Impotence Research
Verified
Journal Article
Open access
PDF file
NWN Wilkes
N Wilkes
SWS White
S White
PSP Stein
P Stein
JBJ Bernie
J Bernie
MRMahadevan Raj Rajasekaran
Mahadevan Raj Rajasekaran
To evaluate the association between hypertension, male erectile function, Rho-kinase, and cyclic GMP pathways, we monitored neurogenic erectile response in spontaneously hypertensive (SHR) vs normotensive rats. We also evaluated SHR erectile function before and after intracavernosal injection of either the specific Rho-kinase inhibitor Y-27632 or a combination of Y-27632 and the PDE5 inhibitor zaprinast to prevent cGMP degradation. SHR had lower resting baseline corpus cavernosum pressure and a higher threshold for development of tumescence than normotensive rats. In SHR, Y-27632 administration reversed hypertension-related changes in male erectile function; Rho-kinase antagonism and PDE5 inhibition in combination had a synergistic effect in improving the neurogenic erectile response. Our data indicate that hypertension is associated with impairment in the SHR neurogenic erectile response that may involve a derangement in hemodynamic mechanisms in penile erectile tissue. Rho-kinase inhibition alone or combined with PDE5 inhibition may be of value in treating hypertension-related ED.