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Biomedical subjects

Parkash Gill

Publications and source records attributed to Parkash Gill.

4 recordsLinked to original sources

Integrating NECTIN4 Amplification With Membranous Nectin-4 Expression to Develop a Scoring System for Predicting Enfortumab Vedotin Response in Urothelial Carcinoma.

PURPOSE: Enfortumab vedotin (EV) is standard therapy for metastatic urothelial carcinoma (mUC), yet the predictive relevance of NECTIN4 expression-especially membranous versus cytoplasmic-remains unclear. Here, we sought to extend previous findings on NECTIN4 gene amplification in parallel with a systematic subcellular evaluation of NECTIN4 expression. EXPERIMENTAL DESIGN: We retrospectively analyzed 179 EV-treated mUC patients. NECTIN4 amplification was assessed by FISH and NECTIN4 protein levels by IHC. A four-tier membranous scoring algorithm (0,1+,2+,3+) adapted from CAP HER2 gastric guidelines was benchmarked against H-score. We integrated amplification status with membranous staining to refine predictive stratification and compared associations with objective response rate (ORR) to EV-301 data. RESULTS: Combining membranous and cytoplasmic compartments resulted in a median composite H-score of 260 (78.2% &#x2265;150), closely matching NECTIN4 expression prevalence reported in EV-301 (median 250; 82.6% &#x2265; 150). A &#x2265;150 cut-off enriched for EV responders in both cohorts; in EV-301 with ORR of 45.8% vs. 20% (P = 0.001). High membranous expression based on the scoring (2+/3+) predicted response (ORR 55.1% vs. 25.5%; P < 0.001), with longer PFS (7.1 vs. 2.9 months; HR 0.45) and OS (12.3 vs. 6.9 months; HR 0.57), whereas cytoplasmic expression lacked predictive value. NECTIN4-amplified tumors showed particularly favorable outcomes (PFS 12.2 months; OS 30.1 months). An integrated three-tier model-amplified, non-amplified/high-membranous, and non-amplified/low-membranous-yielded ORRs of 77.2%, 42.9%, and 26.1% and separated survival outcomes. CONCLUSIONS: Our NECTIN4 scoring system integrating NECTIN4 amplification with membranous NECTIN4 expression accurately predicts outcomes, supporting combined genomic and membranous assessment as complementary biomarkers for optimizing EV selection.

Journal Article↗

Angiogenesis inhibitor IM862 is ineffective against AIDS-Kaposi's sarcoma in a phase III trial, but demonstrates sustained, potent effect of highly active antiretroviral therapy: from the AIDS Malignancy Consortium and IM862 Study Team.

PURPOSE: IM862 is a synthetic dipeptide (L-glutamine L-tryptophan) with in vitro and in vivo antiangiogenic properties. Phase I/II studies showed minimal toxicity and a response rate of 36% in AIDS-Kaposi's sarcoma. We report a 24-week, randomized, double-blinded, placebo-controlled phase III trial with the phase II dose, 5 mg intranasally every other day. PATIENTS AND METHODS: Two hundred two HIV-positive patients were enrolled, 104 on IM862 and 98 on placebo. RESULTS: Baseline characteristics were comparable except current antiretroviral therapy: 88% versus 96% (IM862 v placebo group; P = .042). The median treatment durations were 19.5 versus 24 weeks (IM862 v placebo). No significant difference was detected in response rate (IM862, 23%; 95% CI, 15% to 32% v placebo, 21%; 95% CI, 14% to 31%; P = .46), time to response (8.5 weeks v 14 weeks; P = .024), or duration of response. However, IM862 was associated with both a shorter time to response (8.5 weeks v 14 weeks; P = .024) and shorter median time to progression (16 weeks, 95% CI, 13 to 27 weeks v 35 weeks, 95% CI, 26 to 114 weeks; P = .012). CONCLUSION: Despite promising phase I and phase II studies, IM862 5 mg every other day was not superior to placebo and may accelerate time to progression. Highly active antiretroviral therapy alone was associated with a substantial rate of sustained tumor response and may have contributed to prior estimates of IM862 response. Therapeutic trials for AIDS-Kaposi's sarcoma must account for ongoing immune reconstitution in the setting of concurrent highly active antiretroviral therapy that may confound estimates of therapeutic activity.

AIDS-Related Opportunistic Infections↗

Alpha-chemokine-mediated signal transduction in human Kaposi's sarcoma spindle cells.

The role of chemokines and their receptors in HIV biology and Kaposi's sarcoma (KS) pathogenesis has recently gained considerable attention. It has been shown that KS-associated human herpes virus type 8 (KSHV/HHV-8) encodes functional homologues of certain chemokines and chemokine receptors. This suggests that chemokines may contribute to the growth and spread of KS seen in AIDS. We found the expression of CXCR4 in primary KS tissue by using in situ hybridization (ISH). Recently, alpha-chemokine receptors CXCR1 and CXCR2 have also been shown to be expressed by KS tissues. We further characterized the expression of these chemokines as well as the signaling events induced upon binding to their respective cognate ligands in the KS 38 spindle cell line. These cells express authentic characteristics of primary KS spindle cells and provide a useful in vitro model for these studies. We observed using RT-PCR that KS 38 cells express mRNA for the alpha-chemokine receptors CXCR1, CXCR2, and CXCR4. We also confirmed the cell surface protein expression by FACS analysis. Characterization of signaling pathways revealed that the alpha-chemokines, IL-8 and stromal cell-derived factor 1alpha (SDF1alpha/CXCL12), activated members of the mitogen-activated protein (MAP) kinase family, including Erk kinase, c-Jun amino terminal kinase (JNK)/stress-activated protein kinase (SAPK) and the p38 MAP kinase. Furthermore, using DNA protein-binding experiments, we have shown that IL-8 increased AP-1 and NF Kappa B activity in these cells. IL-8 also enhanced the chemotaxis of KS cells. These results reveal that chemokine-induced signaling pathways may mediate cell growth, transcriptional activation and cell migration in KS.

Cell Line, Tumor↗