Chul Ahn

Prof. Chul Ahn

Department of Population and Data Sciences, UT Southwestern Medical Center, Dallas, TX 75390, USA

Research Focus & Metrics

Academic Career Length

30Years (1997-Present)

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

Representative Publications

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15 September 2014 in Arthritis & Rheumatology
Verified
Journal Article
Open access
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HJHeidi Jacobe
Heidi Jacobe
Chul AhnChul Ahn
Chul Ahn
FAFrank C. Arnett
Frank C. Arnett
JRJohn D. Reveille
John D. Reveille
Objective: To determine the HLA class I and class II alleles of the human major histocompatibility complex showing an association with morphea (localized scleroderma) in the Morphea in Adults and Children (MAC) cohort, using a nested case–control association study.Methods: Patients with morphea were identified from the MAC cohort, and matched controls were obtained from the National Institutes of Health/National Institute of Arthritis and Musculoskeletal and Skin Diseases Scleroderma Family Registry and DNA Repository and from the Division of Rheumatology at the University of Texas Health Science Center at Houston. HLA class II genotyping and single‐strand conformational polymorphism typing were performed to identify HLA–A, B, and C alleles. Associations between HLA class I and class II alleles and morphea, as well as its subphenotypes, were determined.Results: Two hundred eleven patients with morphea and 726 matched controls were available for HLA class I typing, and 158 patients with morphea and 1,008 matched controls were available for HLA class II typing. The strongest associations were found with DRB1*04:04 (odds ratio [OR] 2.3, 95% confidence interval [95% CI] 1.4–4.0, P = 0.002), and HLA–B*37 conferred the highest OR among the class I alleles (OR 3.2, 95% CI 1.5–6.5, P = 0.001). Comparison of the risk allele profile in this cohort with the risk alleles previously identified in patients with systemic sclerosis, determined using the same methods and same control population, revealed one allele in common, DRB*04:04.Conclusion: These results demonstrate that specific HLA class I and class II alleles are associated with morphea and are also likely to be associated with generalized and linear subtypes of morphea. The morphea‐associated alleles are different from those found in scleroderma, suggesting that morphea is immunogenetically distinct. Risk alleles in morphea are also associated with conditions such as rheumatoid arthritis (RA) and other autoimmune conditions. Population‐based studies have indicated that patients with RA have an increased risk of morphea, and therefore a common susceptibility allele may be implicated.

1 March 2014 in Journal of the American Academy of Dermatology
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Journal Article
Closed access
RVRebecca Vasquez
Rebecca Vasquez
AJAysha Jabbar
Aysha Jabbar
FKFatima Khan
Fatima Khan
DBDouglas Buethe
Douglas Buethe
Chul AhnChul Ahn
Chul Ahn
HJHeidi Jacobe
Heidi Jacobe

7 May 2015 in Digestive Diseases and Sciences
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NPNeha Patel
Neha Patel
LTLiyue Tong
Liyue Tong
Chul AhnChul Ahn
Chul Ahn
ASAmit Singal
Amit Singal
SGSamir Gupta
Samir Gupta

26 June 2023 in Clinical Cancer Research
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Journal Article
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DSDavid J. Sher
David J. Sher
DMDominic Moon
Dominic Moon
DVDat Vo
Dat Vo
JWJing Wang
Jing Wang
LCLiyuan Chen
Liyuan Chen
VAVladimir Avkshtol
Vladimir Avkshtol
Purpose: Elective neck irradiation (ENI) has long been considered mandatory when treating head and neck squamous cell carcinoma (HNSCC) with definitive radiotherapy, but it is associated with significant dose to normal organs-at-risk (OAR). In this prospective phase II study, we investigated the efficacy and tolerability of eliminating ENI and strictly treating involved and suspicious lymph nodes (LN) with intensity-modulated radiotherapy. Patients and Methods: Patients with newly diagnosed HNSCC of the oropharynx, larynx, and hypopharynx were eligible for enrollment. Each LN was characterized as involved or suspicious based on radiologic criteria and an in-house artificial intelligence (AI)–based classification model. Gross disease received 70 Gray (Gy) in 35 fractions and suspicious LNs were treated with 66.5 Gy, without ENI. The primary endpoint was solitary elective volume recurrence, with secondary endpoints including patterns-of-failure and patient-reported outcomes. Results: Sixty-seven patients were enrolled, with 18 larynx/hypopharynx and 49 oropharynx cancer. With a median follow-up of 33.4 months, the 2-year risk of solitary elective nodal recurrence was 0%. Gastrostomy tubes were placed in 14 (21%), with median removal after 2.9 months for disease-free patients; no disease-free patient is chronically dependent. Grade I/II dermatitis was seen in 90%/10%. There was no significant decline in composite MD Anderson Dysphagia Index scores after treatment, with means of 89.1 and 92.6 at 12 and 24 months, respectively. Conclusions: These results suggest that eliminating ENI is oncologically sound for HNSCC, with highly favorable quality-of-life outcomes. Additional prospective studies are needed to support this promising paradigm before implementation in any nontrial setting.

26 August 2020 in Clinical Cancer Research
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DGDavid Gerber
David Gerber
William C. (Trey) PutnamWilliam C. (Trey) Putnam
William C. (Trey) Putnam
FFFarjana J. Fattah
Farjana J. Fattah
KKKemp H. Kernstine
Kemp H. Kernstine
Rolf BrekkenRolf Brekken
Rolf Brekken
JKJames Kim
James Kim
Purpose: Itraconazole has been repurposed as an anticancer therapeutic agent for multiple malignancies. In preclinical models, itraconazole has antiangiogenic properties and inhibits Hedgehog pathway activity. We performed a window-of-opportunity trial to determine the biologic effects of itraconazole in human patients. Experimental Design: Patients with non–small cell lung cancer (NSCLC) who had planned for surgical resection were administered with itraconazole 300 mg orally twice daily for 10–14 days. Patients underwent dynamic contrast-enhanced MRI and plasma collection for pharmacokinetic and pharmacodynamic analyses. Tissues from pretreatment biopsy, surgical resection, and skin biopsies were analyzed for itraconazole and hydroxyitraconazole concentration, and vascular and Hedgehog pathway biomarkers. Results: Thirteen patients were enrolled in this study. Itraconazole was well-tolerated. Steady-state plasma concentrations of itraconazole and hydroxyitraconazole demonstrated a 6-fold difference across patients. Tumor itraconazole concentrations trended with and exceeded those of plasma. Greater itraconazole levels were significantly and meaningfully associated with reduction in tumor volume (Spearman correlation, −0.71; P = 0.05) and tumor perfusion (Ktrans; Spearman correlation, −0.71; P = 0.01), decrease in the proangiogenic cytokines IL1b (Spearman correlation, −0.73; P = 0.01) and GM-CSF (Spearman correlation, −1.00; P < 0.001), and reduction in tumor microvessel density (Spearman correlation, −0.69; P = 0.03). Itraconazole-treated tumors also demonstrated distinct metabolic profiles. Itraconazole treatment did not alter transcription of GLI1 and PTCH1 mRNA. Patient size, renal function, and hepatic function did not predict itraconazole concentrations. Conclusions: Itraconazole demonstrates concentration-dependent early antivascular, metabolic, and antitumor effects in patients with NSCLC. As the number of fixed dose cancer therapies increases, attention to interpatient pharmacokinetics and pharmacodynamics differences may be warranted.

24 April 2023 in JCI Insight
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Journal Article
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PIPuneeth Iyengar
Puneeth Iyengar
AGAakash Y. Gandhi
Aakash Y. Gandhi
JGJorge Granados
Jorge Granados
TGTong Guo
Tong Guo
AGArun Gupta
Arun Gupta
RIRodney Infante
Rodney Infante
Cancer cachexia (CC), a wasting syndrome of muscle and adipose tissue resulting in weight loss, is observed in 50% of patients with solid tumors. Management of CC is limited by the absence of biomarkers and knowledge of molecules that drive its phenotype. To identify such molecules, we injected 54 human non–small cell lung cancer (NSCLC) lines into immunodeficient mice, 17 of which produced an unambiguous phenotype of cachexia or non-cachexia. Whole-exome sequencing revealed that 8 of 10 cachexia lines, but none of the non-cachexia lines, possessed mutations in serine/threonine kinase 11 ( STK11/LKB1 ), a regulator of nutrient sensor AMPK. Silencing of STK11/LKB1 in human NSCLC and murine colorectal carcinoma lines conferred a cachexia phenotype after cell transplantation into immunodeficient (human NSCLC) and immunocompetent (murine colorectal carcinoma) models. This host wasting was associated with an alteration in the immune cell repertoire of the tumor microenvironments that led to increases in local mRNA expression and serum levels of CC-associated cytokines. Mutational analysis of circulating tumor DNA from patients with NSCLC identified 89% concordance between STK11/LKB1 mutations and weight loss at cancer diagnosis. The current data provide evidence that tumor STK11/LKB1 loss of function is a driver of CC, simultaneously serving as a genetic biomarker for this wasting syndrome.