Harsh B Pathak

Dr. Harsh B Pathak


Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

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

Representative Publications

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4 December 2015 in PLOS ONE
Verified
Journal Article
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HPHarsh B Pathak
Harsh B Pathak
YZYan Zhou
Yan Zhou
GSGeetika Sethi
Geetika Sethi
JHJeff Hirst
Jeff Hirst
RSRussell J Schilder
Russell J Schilder
AGAndrew Godwin
Andrew Godwin
Molecular targeted therapies have been the focus of recent clinical trials for the treatment of patients with recurrent epithelial ovarian cancer (EOC). The majority have not fared well as monotherapies for improving survival of these patients. Poor bioavailability, lack of predictive biomarkers, and the presence of multiple survival pathways can all diminish the success of a targeted agent. Dasatinib is a tyrosine kinase inhibitor of the Src-family kinases (SFK) and in preclinical studies shown to have substantial activity in EOC. However, when evaluated in a phase 2 clinical trial for patients with recurrent or persistent EOC, it was found to have minimal activity. We hypothesized that synthetic lethality screens performed using a cogently designed siRNA library would identify second-site molecular targets that could synergize with SFK inhibition and improve dasatinib efficacy. Using a systematic approach, we performed primary siRNA screening using a library focused on 638 genes corresponding to a network centered on EGFR, HER2, and the SFK-scaffolding proteins BCAR1, NEDD9, and EFS to screen EOC cells in combination with dasatinib. We followed up with validation studies including deconvolution screening, quantitative PCR to confirm effective gene silencing, correlation of gene expression with dasatinib sensitivity, and assessment of the clinical relevance of hits using TCGA ovarian cancer data. A refined list of five candidates (CSNK2A1, DAG1, GRB2, PRKCE, and VAV1) was identified as showing the greatest potential for improving sensitivity to dasatinib in EOC. Of these, CSNK2A1, which codes for the catalytic alpha subunit of protein kinase CK2, was selected for additional evaluation. Synergistic activity of the clinically relevant inhibitor of CK2, CX-4945, with dasatinib in reducing cell proliferation and increasing apoptosis was observed across multiple EOC cell lines. This overall approach to improving drug efficacy can be applied to other targeted agents that have similarly shown poor clinical activity.

26 October 2023 in Scientific Reports
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Journal Article
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CTCamille V. Trinidad
Camille V. Trinidad
HPHarsh B Pathak
Harsh B Pathak
SCShibo Cheng
Shibo Cheng
STShin-Cheng Tzeng
Shin-Cheng Tzeng
RMRashna Madan
Rashna Madan
AGAndrew Godwin
Andrew Godwin
High grade serous ovarian carcinoma (HGSOC) accounts for ~ 70% of ovarian cancer cases. Non-invasive, highly specific blood-based tests for pre-symptomatic screening in women are crucial to reducing the mortality associated with this disease. Since most HGSOCs typically arise from the fallopian tubes (FT), our biomarker search focused on proteins found on the surface of extracellular vesicles (EVs) released by both FT and HGSOC tissue explants and representative cell lines. Using mass spectrometry, 985 EV proteins (exo-proteins) were identified that comprised the FT/HGSOC EV core proteome. Transmembrane exo-proteins were prioritized because these could serve as antigens for capture and/or detection. With a nano-engineered microfluidic platform, six newly discovered exo-proteins (ACSL4, IGSF8, ITGA2, ITGA5, ITGB3, MYOF) plus a known HGSOC associated protein, FOLR1 exhibited classification performance ranging from 85 to 98% in a case–control study using plasma samples representative of early (including stage IA/B) and late stage (stage III) HGSOCs. Furthermore, by a linear combination of IGSF8 and ITGA5 based on logistic regression analysis, we achieved a sensitivity of 80% with 99.8% specificity and a positive predictive value of 13.8%. Importantly, these exo-proteins also can accurately discriminate between ovarian and 12 types of cancers commonly diagnosed in women. Our studies demonstrate that these lineage-associated exo-biomarkers can detect ovarian cancer with high specificity and sensitivity early and potentially while localized to the FT when patient outcomes are more favorable.

30 September 2022 in Science Advances
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Journal Article
Open access
SGSachindra S. T. Gamage
Sachindra S. T. Gamage
TPThilanga N. Pahattuge
Thilanga N. Pahattuge
HWHarshani Wijerathne
Harshani Wijerathne
KCKatie Childers
Katie Childers
SVSwarnagowri Vaidyanathan
Swarnagowri Vaidyanathan
SSSteven Soper
Steven Soper
We report a microfluidic assay to select active severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral particles (VPs), which were defined as intact particles with an accessible angiotensin-converting enzyme 2 receptor binding domain (RBD) on the spike (S) protein, from clinical samples. Affinity selection of SARS-CoV-2 particles was carried out using injection molded microfluidic chips, which allow for high-scale production to accommodate large-scale screening. The microfluidic contained a surface-bound aptamer directed against the virus’s S protein RBD to affinity select SARS-CoV-2 VPs. Following selection (~94% recovery), the VPs were released from the chip’s surface using a blue light light-emitting diode (89% efficiency). Selected SARS-CoV-2 VP enumeration was carried out using reverse transcription quantitative polymerase chain reaction. The VP selection assay successfully identified healthy donors (clinical specificity = 100%) and 19 of 20 patients with coronavirus disease 2019 (COVID-19) (95% sensitivity). In 15 patients with COVID-19, the presence of active SARS-CoV-2 VPs was found. The chip can be reprogrammed for any VP or exosomes by simply changing the affinity agent.

13 June 2025 in Cytotherapy
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Journal Article
Open access
MLMeizhang Li
Meizhang Li
RSRupal Soder
Rupal Soder
SASunil Abhyankar
Sunil Abhyankar
THTrisha Home
Trisha Home
HPHarsh B Pathak
Harsh B Pathak
HAHaitham Abdelhakim
Haitham Abdelhakim
Human mesenchymal stromal cells (MSCs), particularly Wharton's jelly-derived MSCs (WJMSCs), offer significant therapeutic potential for complex immune conditions such as graft versus host disease (GVHD), in part through their secreted small extracellular vesicles (sEVs). These sEVs exhibit crucial immunomodulatory properties, including suppression of T-cell activation demonstrated both in healthy donor cells and in pathologic contexts. Despite this promise, widespread clinical application is impeded by substantial challenges in developing robust, scalable, and Good Manufacturing Practice (GMP)-compliant manufacturing processes for MSC-derived sEVs to meet clinical demand. To address the critical barriers in sEV production, this study details the development and validation of a reliable and scalable manufacturing platform for WJMSC-derived sEVs. The process utilized GMP expanded WJMSC culture medium, generated from cultured low-passage cells and processed in scalable 2-L and 6-L batch volumes. This platform employed a sequential approach involving tangential flow filtration (TFF) for efficient initial concentration followed by size-exclusion chromatography (SEC) for comprehensive final purification of sEVs. The integrated TFF-SEC manufacturing approach resulted in a significant enrichment of nanoparticles, demonstrating up to a 16.9- and 36-fold increase in particle concentration post-TFF from the 2-L and 6-L batches, respectively. Two batches of purified sEVs demonstrated very similar mean size ranges, from 142 ± 2 nm to 156 ± 2 nm, and displayed the markers CD9 and CD81 while not expressing the negative marker calnexin. Those WJMSC-derived sEVs maintained their biological activity, effectively suppressing - cell activation in vitro. Furthermore, the purified sEVs from both 2-L and 6-L batches demonstrated an intact structure observed by cryogenic electron microscopy (cryo-EM), positivity for the inhibitory immune checkpoint ligand PD-L1. In this study, we report a reliable large-scale manufacturing framework that combines TFF and SEC to manufacture WJMSC-derived sEVs. The established standard operating procedures (SOPs) will help guide the design and establishment of industrial-scale, clinical-grade WJMSC-derived sEV manufacturing. This work significantly advances the field by offering a practical pathway that is anticipated to facilitate the broader development and accelerate the clinical translation of these WJMSC-derived sEVs as potent, cell-free therapeutic agents for various human diseases.

19 October 2016 in BMC Genomics
Verified
Journal Article
Open access
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RRRama Raghavan
Rama Raghavan
SHStephen Hyter
Stephen Hyter
HPHarsh B Pathak
Harsh B Pathak
AGAndrew Godwin
Andrew Godwin
GKGottfried Konecny
Gottfried Konecny
BFBrooke Fridley
Brooke Fridley
Epithelial ovarian cancer (EOC) is the fifth leading cause of cancer death among women in the United States (5 % of cancer deaths). The standard treatment for patients with advanced EOC is initial debulking surgery followed by carboplatin-paclitaxel combination chemotherapy. Unfortunately, with chemotherapy most patients relapse and die resulting in a five-year overall survival around 45 %. Thus, finding novel therapeutics for treating EOC is essential. Connectivity Mapping (CMAP) has been used widely in cancer drug discovery and generally has relied on cancer cell line gene expression and drug phenotype data. Therefore, we took a CMAP approach based on tumor information and clinical endpoints from high grade serous EOC patients. We determined tumor gene expression signatures (e.g., sets of genes) associated with time to recurrence (with and without adjustment for additional clinical covariates) among patients within TCGA (n = 407) and, separately, from the Mayo Clinic (n = 326). Each gene signature was inputted into CMAP software (Broad Institute) to determine a set of drugs for which our signature “matches” the “reference” signature, and drugs that overlapped between the CMAP analyses and the two studies were carried forward for validation studies involving drug screens on a set of 10 EOC cell lines. Of the 11 drugs carried forward, five (mitoxantrone, podophyllotoxin, wortmannin, doxorubicin, and 17-AAG) were known a priori to be cytotoxics and were indeed shown to effect EOC cell viability. Future research is needed to investigate the use of these CMAP and similar analyses for determining combination therapies that might work synergistically to kill cancer cells and to apply this in silico bioinformatics approach using clinical outcomes to other cancer drug screening studies.

27 March 2023 in Bioengineering
Verified
Journal Article
Open access
PDF file
DZDidi Zha
Didi Zha
SRSagar Rayamajhi
Sagar Rayamajhi
JSJared Sipes
Jared Sipes
ARAngela Russo
Angela Russo
HPHarsh B Pathak
Harsh B Pathak
JBJoanna E. Burdette
Joanna E. Burdette
The human fallopian tube epithelium (hFTE) is the site of fertilization, early embryo development, and the origin of most high-grade serous ovarian cancers (HGSOCs). Little is known about the content and functions of hFTE-derived small extracellular vesicles (sEVs) due to the limitations of biomaterials and proper culture methods. We have established a microfluidic platform to culture hFTE for EV collection with adequate yield for mass spectrometry-based proteomic profiling, and reported 295 common hFTE sEV proteins for the first time. These proteins are associated with exocytosis, neutrophil degranulation, and wound healing, and some are crucial for fertilization processes. In addition, by correlating sEV protein profiles with hFTE tissue transcripts characterized using GeoMx® Cancer Transcriptome Atlas, spatial transcriptomics analysis revealed cell-type-specific transcripts of hFTE that encode sEVs proteins, among which, FLNA, TUBB, JUP, and FLNC were differentially expressed in secretory cells, the precursor cells for HGSOC. Our study provides insights into the establishment of the baseline proteomic profile of sEVs derived from hFTE tissue, and its correlation with hFTE lineage-specific transcripts, which can be used to evaluate whether the fallopian tube shifts its sEV cargo during ovarian cancer carcinogenesis and the role of sEV proteins in fallopian tube reproductive functions.