Biomedical subjects

Gerald Batist

Publications and source records attributed to Gerald Batist.

At least 19 recordsLinked to original sources

PubMed2026

Worldwide Innovative Network Consortium: Building a Common Global Cancer Database.

This review shares the ongoing work of the global Worldwide Innovative Network (WIN) Consortium for Precision Medicine to synthesize emerging cancer treatment data and to define the requirements for a common global cancer database that can truly support precision oncology. We performed a narrative review of emerging cancer treatment data, molecular profiling technologies, and existing clinicogenomic databases, focusing on how tumors are characterized, how subgroups are defined, and how demographic, lifestyle, and environmental factors are captured. The growth in molecular profiling technologies and the development of new targeted therapies are transforming cancer care. Tumors, regardless of tissue origin, are increasingly defined as composites of multiple, often rare, subgroups, each with distinct biology and likely response to specific therapies, based on multidimensional profiling of the tumor and its microenvironment. The solution lies in building vast databases that capture racial and ethnic diversity, reflected in genomic data, as well as diet and lifestyle factors that may have epigenetic impact on gene expression and post-translational modifications. A truly inclusive and informative data set must reflect global diversity, and there are multiple examples of demography-dependent differences in genomic signals. With members caring for and studying patients with cancer across five continents, WIN is actively exploring pathways to create a global cancer database, rich in clinical and molecular detail, granular enough for precise analysis, and large enough to power artificial intelligence-driven insights, provided appropriate data quality, validation, and governance frameworks are in place. This review surveys the current landscape and outlines practical paths forward to achieve this goal.

Humans↗

PubMed2025

Worldwide Innovative Network (WIN) Consortium in Personalized Cancer Medicine: Bringing next-generation precision oncology to patients.

The human genome project ushered in a genomic medicine era that was largely unimaginable three decades ago. Discoveries of druggable cancer drivers enabled biomarker-driven gene- and immune-targeted therapy and transformed cancer treatment. Minimizing treatment not expected to benefit, and toxicity-including financial and time-are important goals of modern oncology. The Worldwide Innovative Network (WIN) Consortium in Personalized Cancer Medicine founded by Drs. John Mendelsohn and Thomas Tursz provided a vision for innovation, collaboration and global impact in precision oncology. Through pursuit of transcriptomic signatures, artificial intelligence (AI) algorithms, global precision cancer medicine clinical trials and input from an international Molecular Tumor Board (MTB), WIN has led the way in demonstrating patient benefit from precision-therapeutics through N-of-1 molecularly-driven studies. WIN Next-Generation Precision Oncology (WINGPO) trials are being developed in the neoadjuvant, adjuvant or metastatic settings, incorporate real-world data, digital pathology, and advanced algorithms to guide MTB prioritization of therapy combinations for a diverse global population. WIN has pursued combinations that target multiple drivers/hallmarks of cancer in individual patients. WIN continues to be impactful through collaboration with industry, government, sponsors, funders, academic and community centers, patient advocates, and other stakeholders to tackle challenges including drug access, costs, regulatory barriers, and patient support. WIN's collaborative next generation of precision oncology trials will guide treatment selection for patients with advanced cancers through MTB and AI algorithms based on serial liquid and tissue biopsies and exploratory omics including transcriptomics, proteomics, metabolomics and functional precision medicine. Our vision is to accelerate the future of precision oncology care.

Humans↗

PubMed2007

Structure-based identification of novel human gamma-glutamylcysteine synthetase inhibitors.

Glutathione depletion represents a potentially important strategy to sensitize tumors to cytotoxic drugs. l-Buthionine-(R,S)-sulfoximine (l-BSO) has been studied in both preclinical and early clinical trials, but limitation on its access has led to a search for alternatives. Using a 3D molecular model of human gamma-glutamylcysteine synthetase (gamma-GCS(H)), the major subunit of the rate-limiting GSH synthetic enzyme, we virtually screened the National Cancer Institute chemical database to identify compounds that could bind to and potentially inhibit gamma-GCS(H). We identified 51 test chemicals, all with structures very distinct from l-BSO. We subjected these compounds to biological assays measuring gamma-GCS(H) inhibition and glutathione (GSH) depletion. Among 10 novel gamma -GCS inhibitors identified, 4 compounds depleted glutathione in cells, and 2 with related structures sensitized tumor cells to melphalan treatment. This work validates the use of model-based database mining and identified inhibitors of gamma-GCS(H) with novel chemical structures.

Antineoplastic Agents↗

PubMed2006

Evaluation of denaturing high-performance liquid chromatography as a rapid detection method for identification of epidermal growth factor receptor mutations in nonsmall-cell lung cancer.

BACKGROUND: Somatic mutations of the epidermal growth factor receptor (EGFR) gene in nonsmall-cell lung cancer (NSCLC) may predict responsiveness to tyrosine kinase inhibitors. These mutations are commonly identified using DNA sequencing methods. Although considered the gold standard, this approach is time-consuming. In addition, this approach requires large diagnostic specimens and a high ratio of tumor-to-normal-tissue DNA for optimal results. The use of denaturing high-performance liquid chromatography (dHPLC) as a method to screen for the 2 predominant EGFR mutations is reported. METHODS: Clinical specimens from 104 NSCLC patients were analyzed for EGFR mutations in exons 19 and 21. After DNA extraction and polymerase chain reaction (PCR), both direct sequencing and dHPLC were performed and the results were compared. RESULTS: Sequencing revealed a total of 7 mutations: 3 deletion mutations in exon 19 and 4 missense mutations in exon 21. dHPLC showed the presence of genomic alterations in 23 samples, including the 7 identified by sequencing plus 16 additional samples (10 in exon 19 and 1 in exon 21). dHPLC fractions were isolated, reamplified, and sequenced to confirm the results. In serial dilution studies, dHPLC was able to detect mutations in samples containing as little as 1.6% to 6.25% mutated DNA, whereas direct sequencing required at least 30%. CONCLUSIONS: dHPLC is an efficient and more sensitive method for screening for genomic alterations in exons 19 and 21 of the EGFR gene compared with direct sequence analysis. These data suggest that dHPLC should be implemented as a screening tool for detection of EGFR mutations.

Arginine↗

PubMed2006

A histone deacetylation-dependent mechanism for transcriptional repression of the gap junction gene cx43 in prostate cancer cells.

BACKGROUND: The connexin 43 gene (cx43, GJA1) mediates gap junctional intercellular communication (GJIC), which regulates tissue homeostasis. cx43 is frequently downregulated in prostate cancer. We investigated the role of a histone deacetylase (HDAC)-dependent mechanism in the transcriptional repression of cx43 in a panel of prostate cancer cells. METHODS: The impact of Trichostatin A (TSA), an inhibitor of HDAC, on exogenous and endogenous cx43 gene transcription was examined by the luciferase assay, Northern blot, nuclear run-on, Western blot, and chromatin immunoprecipitation assays. RESULTS: Trichostatin A induces transcription of cx43 gene and GJIC. The co-activator p300/CBP synergizes with TSA for cx43 promoter activation. We identified a promoter region where cooperation between Ap1 and Sp1 elements was essential for TSA-induced cx43 transcription. TSA increased the level of hyperacetylated histones bound to cx43 promoter. CONCLUSION: Our results highlight the potential utility of inhibitors of HDAC to restore cx43 gene expression in prostate cancer.

Acetylation↗

PubMed2006

The flavonoid Casticin has multiple mechanisms of tumor cytotoxicity action.

We studied the mechanism of anti-tumor activity of the flavonoid Casticin, derived from Achillea millefolium. Casticin anti-tumor activity results in cell growth arrest in G2/M and in apoptotic death. As a tubulin-binding agent (TBA), Casticin induces p21, which in turn inhibits Cdk1. Moreover, Casticin appears to down regulate cyclin A. These observations could explain Casticin-induced G2/M arrest. Following Casticin exposure, Bcl-2 depletion occurs in cancer cells, and a sub-G1 accumulation occurs in the cell cycle. Moreover, following a transient transfection with Bcl-2, MN1 cells are resistant to Casticin. A number of features suggest that Casticin could be important in cancer therapy. Indeed, Pgp over expressing cells are not resistant to Casticin, and its cell killing effect is observed even in p53 mutant or null cell lines.

Antineoplastic Agents↗

PubMed2006

Improved anti-tumor response rate with decreased cardiotoxicity of non-pegylated liposomal doxorubicin compared with conventional doxorubicin in first-line treatment of metastatic breast cancer in patients who had received prior adjuvant doxorubicin: results of a retrospective analysis.

Our objectives were to ascertain the safety (cardiotoxicity) and efficacy of non-pegylated liposomal doxorubicin [Myocet (M)] compared with conventional doxorubicin (A) in patients with metastatic breast cancer (MBC) who had received adjuvant anthracycline treatment and were at high risk of developing iatrogenic cardiomyopathy. This retrospective analysis is based on data pooled from two prospective phase III comparative randomized clinical trials comparing Myocet versus conventional doxorubicin in combination with cyclophosphamide and as single agents, respectively, for the treatment of MBC. The outcome measures reviewed in this analysis were overall response, time to treatment failure, time to disease progression, overall survival and cardiotoxicity. The analysis was carried out by strata according to patients' previous exposure to adjuvant anthracyclines. Kaplan-Meier, log-rank chi-test, Cox proportional-hazards and Cochran-Mantel-Haenszel statistics were used for the analysis. Sixty-eight patients were included in this analysis: 29 and 39 patients from Studies 1 and 2, respectively, had received adjuvant anthracycline treatment. Study 1, with n=297, compared M 60 mg/m (M60) plus cyclophosphamide (C) 600 mg/m (C600) versus A 60 mg/m (A60) plus C600 as first-line treatment for MBC. Twenty-nine patients had received prior adjuvant doxorubicin, of whom, after randomization, 14 received M60+C600 and 15 received A60+C600 for the treatment of MBC. Study 2, with n=224, compared M 75 mg/m (M75) with A 75 mg/m (A75) as first-line treatment for MBC disease. Thirty-nine patients had received prior adjuvant doxorubicin, of whom, after randomization, 18 received M75 and 21 received A75 for their MBC. Hence, 32 patients received M-containing regimens and 36 received A-containing regimens for the treatment of MBC. Median age in both groups was 54 years. The groups were well balanced in terms of demographic characteristics. Overall response rates were 31% and 11% for M-treated patients and A-treated patients, respectively (Cochran-Mantel-Haenszel P=0.04, odds ratio=4.0). Median time to progression was 4.5 versus 3.4 months [log-rank P=0.66, hazard ratio (HR)=1.14], median time to treatment failure was 4.2 versus 2.1 months (log-rank P=0.01, HR=2.06) and median survival time was 16 versus 15 months (log-rank P=0.71, HR=1.12). Cardiac events occurred in 22% of M-treated patients [one congestive heart failure (CHF)] versus 39% of A-treated patients (three CHFs) (log-rank, P=0.001). Median lifetime dose at onset of cardiotoxicity was 780 mg/m for M versus 580 mg/m for A (log-rank P=0.001, HR=4.8). This retrospective analysis shows that treatment based on non-pegylated liposomal doxorubicin (Myocet) significantly reduced the risk of cardiotoxicity in patients with MBC who had received prior adjuvant doxorubicin. Furthermore, anti-tumor activity and time to treatment failure were significantly improved compared with patients who received treatment based on conventional doxorubicin for their MBC. This analysis revisits the therapeutic option of including doxorubicin in the treatment of MBC patients who have had prior adjuvant anthracycline exposure.

Adult↗

PubMed2006

[The réseau de recherche sur le cancer: favoring a multi-disciplinary approach].

The Réseau de recherche sur le cancer (RR-cancer) a unit of the Fonds de la recherche en santé du Québec (FRSQ) has joined the worldwide effort to uncover mechanisms involved in cancer development through its well established clinical and fundamental research units. Encouraged by the excellence of the Quebec research community, the RR-cancer has developed a specialized infrastructure which allows better access to tissues and to state of the art analysis services. The research is founded on four axes: 1) Database and Tissue Bank; 2) Leukaemia cell bank; 3) Experimental therapy and 4) the Oncological Research Group of Québec. With these programs, the RR-cancer contributes to ameliorating prevention, diagnosis and treatment of cancer by facilitating access to the highest quality research material. Optimization of resources is made possible by the contributions of basic scientists and clinicians working together towards a unified objective: fighting cancer.

Academies and Institutes↗

PubMed2005

Transcriptional regulation of NF-E2 p45-related factor (NRF2) expression by the aryl hydrocarbon receptor-xenobiotic response element signaling pathway: direct cross-talk between phase I and II drug-metabolizing enzymes.

The aryl hydrocarbon receptor (AHR) and NF-E2 p45-related factor (NRF2) are two distinct transcription factors involved in the regulation of drug-metabolizing enzymes. Increasing evidence from several studies implies that AHR and NRF2 have direct links, but the molecular mechanism remains unknown. In this work we demonstrate for the first time that Nrf2 gene transcription is directly modulated by AHR activation. DNA sequence analyses of the mouse Nrf2 promoter revealed one xenobiotic response element (XRE)-like element (XREL1) located at -712 and two additional XRE-like elements located at +755 (XREL2) and +850 (XREL3). Functional analysis using luciferase assay showed that XREL1, XREL2, and XREL3 are all inducible by 2,3,7,8-tetrachlorodibenzo-p-dioxin treatment, with XREL2 being the most potent. The functionality of these XRE-like elements was further confirmed by mutagenesis and gel shift experiments. Finally, we used chromatin immunoprecipitation assay to show a direct binding of AHR to the Nrf2 promoter. Cells with silenced AHR expression using siRNA also lost NRF2 mRNA induction by 2,3,7,8-tetrachlorodibenzo-p-dioxin. These new data position NRF2-antioxidant response element downstream in the AHR-XRE pathway. Moreover, direct regulation of NRF2 by AHR contributes to couple phase I and II enzymes into an integrated system facilitating more effective xenobiotic and carcinogen detoxification.

Animals↗

PubMed2005

Phase I and pharmacokinetic study of Bay 38-3441, a camptothecin glycoconjugate, administered as a 30-minute infusion daily for five days every 3 weeks in patients with advanced solid malignancies.

Bay 38-3441 is a camptothecin glycoconjugate which stabilizes the active lactone form of camptothecin and allows selective uptake into tumor cells. We conducted a phase I study of Bay 38-3441 administered as a 30-minute infusion daily for five consecutive days every 21 days. Thirty-one patients were enrolled at 8 dose levels. Most common nonhematologic side effects were diarrhea (29%), vomiting (19%), nausea (19%), lethargy (13%), and abdominal pain (10%). The main hematologic toxicity was prolonged neutropenia. Nine patients had a best response of stable disease with a median duration of 2.7 months (range: 2.3-20.6 months). The study was closed without reaching the maximum tolerated dose (MTD) due to excessive toxicity in a companion trial resulting in termination of development of this agent. Bay 38-3441 was well tolerated in this study with granulocytopenia as the main hematologic toxicity. This study showed that glycoconjugation is a feasible delivery technique for camptothecin.

Adult↗

PubMed2005

A phase II trial of ZD1839 (Iressa) 750 mg per day, an oral epidermal growth factor receptor-tyrosine kinase inhibitor, in patients with metastatic colorectal cancer.

PURPOSE: The epidermal growth factor receptor (EGFR) appears relevant in the pathogenesis and progression of colorectal cancer. After completing a phase I pharmacodynamic trial of ZD1839, we undertook a dose expansion trial to examine the antitumour efficacy and adverse effect profile of this agent in a homogeneous group of patients with metastatic colorectal cancer (CRC). EXPERIMENTAL DESIGN: Eligible patients with metastatic or recurrent CRC received ZD1839 750 mg daily by mouth. This dose was selected based on a phase I trial conducted by the National Cancer Institute of Canada Clinical Trials Group (NCIC CTG). Treatment was continued until unacceptable toxicity or disease progression. RESULTS: Twenty-eight patients were enrolled at three NCIC CTG centers. Twenty-three patients had received prior chemotherapy; 12 patients had received three or more regimens. No objective responses were observed in 24 evaluable patients, although 8 patients had stable disease (median duration of 2.2 months). The most frequent drug related adverse events were diarrhea, rash and nausea. Eleven patients required dosing modification (hold or reduction), while 3 patients discontinued therapy because of toxicity. There were no treatment related deaths. CONCLUSIONS: ZD1839, when given at 750 mg/day to patients with pre-treated metastatic colorectal cancer, does not result in significant tumor regression.

Adult↗

PubMed2005

TLK-199 (Telik).

Telik Inc is developing TLK-199, an intravenous inhibitor of glutathione S-transferase P1-1, for the potential prevention of myelosuppression in blood diseases, namely myelodysplastic syndrome.

Animals↗

PubMed2005

Anthracyclines.

Explore the source record for details and available documents.

Anthracyclines↗

PubMed2004

Cyclin D1 is essential for neoplastic transformation induced by both E6/E7 and E6/E7/ErbB-2 cooperation in normal cells.

More than 25% of head and neck squamous cell carcinomas (HNSCC) and 99% of cervical cancers (CxCa) are positive for high-risk human papillomaviruses (HPVs). Furthermore, the type I tyrosine kinase receptor ErbB-2 is overexpressed in at least 30% of HNSCC and CxCa. Recently, we demonstrated that E6/E7 of HPV type 16 cooperate with ErbB-2 to induce cell transformation of human normal oral epithelial (NOE) cells. This is accompanied by overexpression of cyclin D1 in NOE cells. To determine the role of cyclin D1 in E6/E7/ErbB-2 cooperation, we examined the independent effects of E6/E7 and ErbB-2, and the combined effect of E6/E7 and ErbB-2 in mouse normal embryonic fibroblast (NEF), wild type (wt), and knockout cyclin D1 (D1(-/-)) cells. We report that NEF-wt cells transduced with E6/E7 alone and E6/E7/ErbB-2 together form small and large tumors in nude mice, respectively, as well as different sized colonies in soft agar; whereas ErbB-2 alone elicits neither tumor formation in vivo nor colony formation in soft agar. More importantly, E6/E7, ErbB-2 and E6/E7/ErbB-2 together all fail to induce neoplastic transformation of cyclin D1(-/-) cells in vivo and in vitro. Furthermore, using antisense cyclin D1 we completely inhibited tumor and colony formation of NEF-wt-E6/E7 and wt-E6/E7-ErbB-2 as well as human NOE-E6/E7-ErbB-2-transformed cells. These analyses reveal that cyclin D1 is the downstream target of the neoplastic transformation induced by E6/E7 or E6/E7/ErbB-2 cooperation in normal cells. Our data suggest that anti-cyclin D1 therapy may be highly specific in the treatment of all human cancers expressing high-risk HPVs or HPVs/ErbB-2.

Animals↗

PubMed2004

Connexin43 pseudogene is expressed in tumor cells and inhibits growth.

Pseudogenes are classically thought of as nonfunctional DNA sequences due to their inability to be translated, or to produce a functional protein. Gap junctions, a multiprotein complex made of proteins called connexins, are involved in intercellular communication and are deregulated in many cancers. Connexin43 (Cx43) is the only connexin for which a pseudogene has been reported so far. The Cx43 pseudogene (PsiCx43) has all of the features of an expressed gene. We identified the presence of a PsiCx43 mRNA transcript in several cancer cell lines and in none of the normal mammary epithelial cells studied. Using an in vitro translation assay, we found that the PsiCx43 coding plasmid could be translated into a 43 kDa protein. This was further confirmed by expressing a PsiCx43-green fluorescence protein fusion protein in breast cancer MCF-7 cells. We then examined the functional significance of the PsiCx43. In both MTT growth and colony formation assays, significant growth inhibition was observed, a feature common to cells overexpressing the Cx43 gene. However, using a scrape-loading assay, we could not detect any effect on gap junctional intercellular communication. Based on our findings, PsiCx43 joins and enlarges the thus far restricted group of functionally transcribed and translated pseudogenes.

Amino Acid Sequence↗

PubMed2004

A cell-based system to identify and characterize the molecular mechanism of drug-metabolizing enzyme (DME) modulators.

Many naturally occurred or synthetic compounds can modulate the body's drug-metabolizing enzymes to enhance carcinogen detoxification, and some have demonstrated remarkable cancer prevention effects. Understanding the molecular mechanism behind each candidate agent is critically important in designing rational cancer chemoprevention strategies. In this work, we have employed a set of molecular mechanism-based assays and characterized eight classes of known drug-metabolizing enzyme (DME) modulators in a cellular system. Examination of mRNA and protein levels of representative phase I and phase II enzymes validated the results obtained in our cell-based system. Our data confirmed that the antioxidant ethoxyquin (EQ) and the isothiolcyanate sulfurophane (SFP) exclusively activate the antioxidant response element (ARE), and thus represent monofunctional inducers. We were also able to reclassify some compounds, and to use the system to identify structure-activity relationships among structurally related but different compounds. Finally, this cell-based system permitted us to identify a potential novel mechanism for cross-talk between the ARE and the xenobiotic response element (XRE)-mediated pathways.

Animals↗

PubMed2004

An examination of how different mutations at arginine 855 of the androgen receptor result in different androgen insensitivity phenotypes.

Two substitutions at an identical location in the ligand-binding domain (LBD) of the human androgen receptor (AR), R855C and R855H, are associated with complete androgen insensitivity syndrome (AIS) and partial AIS, respectively. Kinetic analysis of the mutant receptors in genital skin fibroblasts and in transfected cells revealed very low total binding (Bmax) and increased rate constants of dissociation (k) for the R855C mutant; and normal Bmax and k, with slightly elevated equilibrium affinity constants (Kd), but decreased transactivational capacity for the R855H mutant. Further analysis of the R855H mutant revealed both thermolability and decreased N/C-terminal inter-actions in the presence and absence of the co-activator transcriptional intermediary factor 2. To establish the nature of these functional differences we have used molecular dynamic modeling to create four-dimensional models of each of the mutant receptors. Molecular dynamic modeling produced profoundly different models for each of the mutants: in modeling of R855C a surprisingly significant distant alteration in the position of helix 12 of the helix 12 positioning of the AR ligand binding domain (AR-LBD) occurs, which would predict severe ligand binding abnormalities and complete AIS; in modeling of R855H, no dramatic effect on the position of helix 12 was seen; thus, binding properties of the receptor are not compromised. Molecular dynamics four-dimensional modeling clearly supports the biochemical and kinetic studies of both mutants. Such novel computational modeling may lead to a better understanding of the structure-function relationships and the molecular mechanics of ligand binding not only of the AR-LBD but also of other nuclear receptors.

Adult↗

PubMed2004

E6/E7 proteins of HPV type 16 and ErbB-2 cooperate to induce neoplastic transformation of primary normal oral epithelial cells.

Head and neck squamous cell carcinomas (HNSCC) are characterized by a marked propensity for local invasion and spread to cervical lymph nodes, with distant metastases developing in 30-40% of cases. HPV-16 is an important risk factor for HNSCC. How HPV enhances susceptibility to HNSCC is not fully understood, but seems to involve cofactors. In this study, we examined the effect of the cooperation between HPV-16 and the tyrosine kinase receptor ErbB-2 on E-cadherin/catenin complex patterns and neoplastic transformation of human normal oral epithelial (NOE) cells. We report that overexpression of ErbB-2 or E6/E7 alone does not affect E-cadherin/catenin complex patterns nor does it induce cell transformation of NOE cells. In contrast, coexpression of E6/E7 and ErbB-2 downregulates E-cadherin and catenin expression. This is accompanied by cytoplasmic localization of E-cadherin, as well as nuclear translocation of alpha, beta, and gamma-catenins. Furthermore, we demonstrate that E6/E7 cooperate with overexpressed ErbB-2 to induce tumor formation in nude mice and to upregulate cyclin D1 and c-myc expression. Our data suggest that E6/E7 cooperate with ErbB-2 in head and neck carcinogenesis, at least in part, via the conversion of beta-catenin from a cell adhesion to a nuclear function, that is, to act as a potential transcriptional regulator. This conversion leads to the upregulation of cyclin D1, c-myc and other oncoproteins necessary for alteration of the E-cadherin/catenin complex and cell transformation of NOE cells.

Animals↗