Jong Rak CHOI

Prof. Jong Rak CHOI


Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

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

Representative Publications

View All Publications
1 March 2018 in Epilepsy Research
Verified
Journal Article
Closed access
AKAra Ko
Ara Ko
SYSong Ee Youn
Song Ee Youn
SKSe Hee Kim
Se Hee Kim
JLJoon Soo Lee
Joon Soo Lee
SKSangwoo Kim
Sangwoo Kim
HKHoon-Chul Kang
Hoon-Chul Kang

1 February 2018 in BMC Medical Genomics
Verified
Journal Article
Open access
PDF file
JRJohn Hoon Rim
John Hoon Rim
SKSe Hee Kim
Se Hee Kim
IHIn Sik Hwang
In Sik Hwang
SKSoon Sung Kwon
Soon Sung Kwon
JKJieun Kim
Jieun Kim
HKHoon-Chul Kang
Hoon-Chul Kang
We intended to evaluate diagnostic utility of a targeted gene sequencing by using next generation sequencing (NGS) panel in patients with intractable early-onset epilepsy (EOE) and find the efficient analytical step for increasing the diagnosis rate. We assessed 74 patients with EOE whose seizures started before 3 years of age using a customized NGS panel that included 172 genes. Single nucleotide variants (SNVs) and exonic and chromosomal copy number variations (CNVs) were intensively examined with our customized pipeline and crosschecked with commercial or pre-built software. Variants were filtered and prioritized by in-depth clinical review, and finally classified according to the American College of Medical Genetics and Genomics guidelines. Each case was further discussed in a monthly consensus meeting that included the participation of all laboratory personnel, bioinformaticians, geneticists, and clinicians. The NGS panel identified 28 patients (37.8%) with genetic abnormalities; 25 patients had pathogenic or likely pathogenic SNVs in 17 genes including SXTBP1 (n = 3), CDKL5 (n = 2), KCNQ2 (n = 2), SCN1A (n = 2), SYNGAP1 (n = 2), GNAO1 (n = 2), KCNT1 (n = 2), BRAT1, WWOX, ZEB2, CHD2, PRICKLE2, COL4A1, DNM1, SCN8A, MECP2, SLC9A6 (n = 1). The other 3 patients had pathogenic CNVs (2 duplications and 1 deletion) with varying sizes (from 2.5 Mb to 12 Mb). The overall diagnostic yield was 37.8% after following our step-by-step approach for clinical consensus. NGS is a useful diagnostic tool with great utility for patients with EOE. Diagnostic yields can be maximized with a standardized and team-based approach.

1 January 2009 in Journal of Clinical Laboratory Analysis
Verified
Journal Article
Open access
PDF file
JYJong‐Ha Yoo
Jong‐Ha Yoo
HMHo‐Young Maeng
Ho‐Young Maeng
YSYoung‐Kyu Sun
Young‐Kyu Sun
YKYoung‐Ah Kim
Young‐Ah Kim
DPDong‐Wook Park
Dong‐Wook Park
JCJong Rak CHOI
Jong Rak CHOI
Oxidative stress is an imbalance between free radicals and antioxidant molecules that can play an important role in the pathogenesis of iron‐deficiency anemia (IDA). The aim of this study was to investigate oxidative status in patients with IDA and alteration of oxidative status after iron treatment. Thirty‐three female patients with IDA and 25 healthy controls were included in this study. Oxidant and total antioxidant capacity were determined using free oxygen radicals test and free oxygen radicals defence (Form CR 3000, Callegari, Parma, Italy). Catalase activity was measured by spectrophotometer using a commercially available kit (Bioxytech Catalase‐520, OxisResearch, Portland, OR). Oxidant activity in patients with IDA was significantly higher than controls (P<0.05), while total antioxidant and catalase activity were significantly lower (P0.05). In conclusion, our data indicate that blood reactive oxygen species was lower and total antioxidant and catalase activity were higher after rather than before treatment in patients with IDA. The results of our study support the higher oxidative stress hypothesis in IDA; however, due to the limited number of cases included, more studies may be required to confirm the results. J. Clin. Lab. Anal. 23:319–323, 2009.

11 August 2009 in Head & Neck
Verified
Journal Article
Closed access
PDF file
JKJin Young Kwak
Jin Young Kwak
EKEun‐Kyung Kim
Eun‐Kyung Kim
JKJong‐Kee Kim
Jong‐Kee Kim
JHJeong‐Hyun Han
Jeong‐Hyun Han
SHSoon Won Hong
Soon Won Hong
JCJong Rak CHOI
Jong Rak CHOI

1 December 2023 in Cancer Research
Verified
Journal Article
Closed access
PDF file
JHJinho Heo
Jinho Heo
YKYoo-Na Kim
Yoo-Na Kim
SSSaeam Shin
Saeam Shin
KLKyunglim Lee
Kyunglim Lee
JLJiHyun Lee
JiHyun Lee
JLJung-Yun Lee
Jung-Yun Lee
Circulating tumor DNA (ctDNA) may aid in personalizing ovarian cancer therapeutic options. Here, we aimed to assess the clinical utility of serial ctDNA testing using tumor-naïve, small-sized next-generation sequencing (NGS) panels. A total of 296 patients, including 201 with ovarian cancer and 95 with benign or borderline disease, were enrolled. Samples were collected at baseline (initial diagnosis or surgery) and every 3 months after that, resulting in a total of 811 blood samples. Patients received adjuvant therapy based on the current standard of care. Cell-free DNA was extracted and sequenced using an NGS panel of 9 genes: TP53, BRCA1, BRCA2, ARID1A, CCNE1, KRAS, MYC, PIK3CA, and PTEN. Pathogenic somatic mutations were identified in 69.2% (139/201) of patients with ovarian cancer at baseline but not in those with benign or borderline disease. Detection of ctDNA at baseline and/or at 6 months follow-up was predictive of progression-free survival (PFS). PFS was significantly poorer in patients with detectable pathogenic mutations at baseline that persisted at follow-up than in patients that converted from having detectable ctDNA at baseline to being undetectable at follow-up; survival did not differ between patients without pathogenic ctDNA mutations in baseline or follow-up samples and those that converted from ctDNA positive to negative. Disease recurrence was also detected earlier with ctDNA than with conventional radiologic assessment or CA125 monitoring. These findings demonstrate that serial ctDNA testing could effectively monitor patients and detect minimal residual disease, facilitating early detection of disease progression and tailoring of adjuvant therapies for ovarian cancer treatment. Significance: In ovarian cancer, serial circulating tumor DNA testing is a highly predictive marker of patient survival, with a significantly improved recurrence detection lead time compared with conventional monitoring tools.

17 April 2023 in Clinical Cancer Research
Verified
Journal Article
Open access
PDF file
YKYoo-Na Kim
Yoo-Na Kim
YSYeeun Shim
Yeeun Shim
JSJieun Seo
Jieun Seo
ZCZisun Choi
Zisun Choi
YLYong Jae Lee
Yong Jae Lee
SLSeung-Tae Lee
Seung-Tae Lee
Purpose: Patient-specific molecular alterations leading to PARP inhibitor (PARPi) resistance are relatively unexplored. In this study, we analyzed serially collected circulating tumor DNA (ctDNA) from patients with BRCA1/2 mutations who received PARPis to investigate the resistance mechanisms and their significance in postprogression treatment response and survival. Experimental Design: Patients were prospectively enrolled between January 2018 and December 2021 (NCT05458973). Whole-blood samples were obtained before PARPi administration and serially every 3 months until progression. ctDNA was extracted from the samples and sequenced with a 531-gene panel; gene sets for each resistance mechanism were curated. Results: Fifty-four patients were included in this analysis. Mutation profiles of genes in pre-PARPi samples indicating a high tumor mutational burden and alterations in genes associated with replication fork stabilization and drug efflux were associated with poor progression-free survival on PARPis. BRCA hypomorphism and reversion were found in 1 and 3 patients, respectively. Among 29 patients with matched samples, mutational heterogeneity increased postprogression on PARPis, showing at least one postspecific mutation in 89.7% of the patients. These mutations indicate non-exclusive acquired resistance mechanisms—homologous recombination repair restoration (28%), replication fork stability (34%), upregulated survival pathway (41%), target loss (10%), and drug efflux (3%). We observed poor progression-free survival with subsequent chemotherapy in patients with homologous recombination repair restoration (P = 0.003) and those with the simultaneous involvement of two or more resistance mechanisms (P = 0.040). Conclusions: Analysis of serial ctDNAs highlighted multiple acquired resistance mechanisms, providing valuable insights for improving postprogression treatment and survival.