Biomedical subjects

Sachin Kumar

Publications and source records attributed to Sachin Kumar.

4 recordsLinked to original sources

PubMed2026

Multi-level Transcriptomic and Machine-learning Analyses Identify MZT1 as a Proliferation-associated Prognostic Marker in Lung Adenocarcinoma.

BACKGROUND/AIM: Lung adenocarcinoma (LUAD) exhibits substantial molecular heterogeneity and variable clinical outcomes, highlighting the need for biomarkers that reflect core tumor biological processes. Centrosome-associated proteins regulate mitotic fidelity and genome stability, yet their roles in LUAD remain incompletely defined. In this study, we systematically characterized mitotic spindle organizing protein 1 (MOZART1; MZT1) and related family members in LUAD. MATERIALS AND METHODS: We performed integrated analyses combining bulk transcriptomic datasets, survival modeling, gene set enrichment, immune deconvolution, machine-learning based prognostic modeling, and single-cell RNA sequencing. Expression patterns and clinical associations of MZT family genes were evaluated across pan-cancer and LUAD cohorts. RESULTS: MZT family genes were consistently upregulated in tumor tissues, with MZT1 showing the most robust expression pattern. Elevated MZT1 expression was significantly associated with reduced overall survival. Functional analyses revealed coordinated activation of proliferative and genome maintenance pathways, including G2/M checkpoint regulation, E2F and MYC signaling, and DNA repair. A multivariable analysis indicated that the prognostic association of MZT1 was reduced after adjusting for canonical proliferation markers, suggesting partial overlap with established proliferation signals. The LASSO-based Cox model demonstrated stable time-dependent predictive performance at 1-, 3-, and 5-year survival. Immune analyses indicated associations between MZT1 expression and tumor microenvironmental features. Single-cell analysis showed that MZT1 expression was predominantly enriched in malignant epithelial cells and associated with proliferative cellular states. Protein-level validation supported concordance with transcriptomic findings. CONCLUSION: MZT1 is a proliferation-associated marker that integrates clinical risk, transcriptional programs, cellular heterogeneity, and predictive modeling in LUAD, providing a potential framework for biomarker development and risk stratification.

Humans↗

PubMed2006

Surface-enhanced Raman spectroscopic study of 1,4-phenylene diisocyanide adsorbed on gold and platinum-group transition metal electrodes.

Self-assembled monolayers of 1, 4-phenylene diisocyanide (PDI) were formed on Au and Pt-group transition metals and examined by surface-enhanced Raman spectroscopy under controlled applied potential. On all of the metals examined, PDI adsorbs in an edge-on manner, with one NC group bound to the surface and the other pointing away from the surface. The N-C stretching frequency (nu(NC)) suggests that depending on the metal, PDI adsorbs on different binding sites: terminal sites on Au, both terminal and bridging on Rh and Pt, and predominantly 3-fold hollow sites for Pd. This binding site preference can be understood in terms of the difference in d-band center energy and d-orbital filling among the metals. The applied potential affects the N-C bonding differently as inferred from the potential dependence of nu(NC). On Au, Rh, and Pd, the nu(NC) increases linearly with the applied potential, yielding a Stark tuning slope, dnu(NC)/dE, of 25, 12, and 10 cm(-1)/V, respectively. On Pt, the nu(NC) is nearly independent of the applied potential. On all of the metals studied, the frequencies of benzene ring vibration modes are not dependent on the applied potential, consistent with the edge-on orientation in which the ring does not directly interact with the surface. Several ring vibrations are, however, sensitive to the nature of metal substrate due to different binding sites involved. The ability of the free NC group to function as an anchoring point is demonstrated by the attachment of gold nanoparticles on PDI-covered Au and Pd. The study provides useful NC-metal bonding information for isocyanide-based molecular electronic developments.

Journal Article↗

PubMed2006

Circulating cell-free DNA in plasma/serum of lung cancer patients as a potential screening and prognostic tool.

BACKGROUND: Evaluation of tumor-specific circulating DNA in plasma/serum is a promising noninvasive diagnostic and prognostic tool requiring only a blood sample, which circumvents the logistic difficulties associated with the use of invasive procedures for serial tumor samplings during screening of lung cancer. METHODS: We reviewed English-language reports published in the MEDLINE database that provided the results of qualitative and quantitative studies on circulating DNA in serum/plasma of lung cancer patients. We searched the bibliographies of the retrieved reports and reviews. Abstracts presented at the 2003, 2004, and 2005 annual meetings of the American Society of Clinical Oncology were also reviewed. RESULTS: More than 80 citations were retrieved, of which 33 met our criteria: 22 qualitative studies, and 11 quantitative studies. The studies varied in the choice of markers, frequency of alterations, sensitivities of used methodologies, sample sizes, treatment protocols, and prognostic correlates evaluated. CONCLUSIONS: The findings from the studies on serum/plasma DNA suggest that it would be possible to develop a simple blood test with high sensitivity and specificity that has potential for screening of high-risk individuals, for prognostic or staging purposes, and to be used as intermediate end-points of efficacy in chemo-prevention and therapeutic trials. However, further work is needed to identify additional biomarkers and to standardize present techniques for sample collection, processing, and analysis. Large prospective studies with long follow-ups are essential to eventually integrate blood marker-based assays into the clinical setting.

Biomarkers, Tumor↗

PubMed2005

Electrooxidation of carbon monoxide on gold nanoparticle ensemble electrodes: effects of particle coverage.

Gold nanoparticles were attached to amine-functionalized indium tin oxide substrate to form particle ensemble electrodes with controlled particle coverage. Electrooxidation of carbon monoxide (CO) on these particle ensemble electrodes was studied in CO-saturated alkaline solutions by means of cyclic voltammetry, with an emphasis on the effects of particle coverage. CO oxidation half-wave potential was found to decrease with increasing particle density. However, the current density was significantly larger at lower particle coverage electrodes. On the basis of a model for electron transfer on a partially covered electrode, the observations were explained in terms of the change in reactant mass transport pattern with varying particle coverages: CO diffusion is predominantly mixed spherical and linear at low particle coverages and changes to mostly linear at high particle coverages. The possibility of contributions from particle agglomeration is also briefly discussed.

Carbon Monoxide↗