ABSTRACT
Purpose@#For precision medicine, exploration and monitoring of molecular biomarkers are essential. However, in advanced gastric cancer (GC) with visceral lesions, an invasive procedure cannot be performed repeatedly for the follow-up of molecular biomarkers. @*Materials and Methods@#To verify the clinical implication of serial liquid biopsies targeting circulating tumor DNA (ctDNA) on treatment response, we conducted targeted deep sequencing for serially collected ctDNA of 15 HER2-positive metastatic GC patients treated with anti-PD-1 inhibitor in combination with standard systemic treatment. @*Results@#In the baseline ctDNAs, 14 patients (93%) harbored more than one genetic alteration. A number of mutations in wellknown cancer-related genes, such as KRAS and PIK3CA, were identified. Copy number alterations were identified in eight GCs (53.3%), and amplification of the ERBB2 gene (6/15, 40.0%) was the most recurrent. When we calculated the mean variant allele frequency (VAF) of mutations in each ctDNA as the molecular tumor burden index (mTBI), the mTBI trend was largely consistent with the VAF profiles in both responder and non-responder groups. Notably, in the longitudinal analysis of ctDNA, mTBI provided 2–42 weeks (mean 13.4 weeks) lead time in the detection of disease progression compared to conventional follow-up with CT imaging. @*Conclusion@#Our data indicate that the serial genetic alteration profiling of ctDNA is feasible to predict treatment response in HER2-positive GC patients in a minimally invasive manner. Practically, ctDNA profiles are useful not only for the molecular diagnosis of GC but also for the selection of GC patients with poor prognosis for systemic treatment (ClinicalTrials.gov identifier:NCT02901301).
ABSTRACT
OBJECTIVE: Tributyltin (TBT), an endocrine disrupting chemical, has been reported to decrease ovarian function by causing apoptosis in the ovary, but the mechanism is not fully understood. Therefore, we examined whether TBT increases the expression of adipogenesis-related genes in the ovary and the increased expression of these genes is associated with apoptosis induction. METHODS: Three-week-old Sprague-Dawley rats were orally administered TBT (1 or 10 mg/kg body weight) or sesame oil as a control for 7 days. The ovaries were obtained and weighed on day 8, and then they were fixed for terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) or frozen for RNA extraction. Using the total RNA of the ovaries, adipogenesis- and apoptosis-related genes were analyzed by real-time polymerase chain reaction (PCR). RESULTS: The ovarian weight was significantly decreased in rats administered 10 mg/kg TBT compared to that in control rats. As determined by the TUNEL assay, the number of apoptotic follicles in ovary was significantly increased in rats administered 10 mg/kg TBT. The real-time PCR results showed that the expression of adipogenesis-related genes such as PPARgamma, aP2, CD36, and PEPCK was increased after TBT administration. In addition, apoptosis-related genes such as TNFalpha and TNFR1 were expressed more in the TBT-administered rats compared with the control rats. CONCLUSION: The present study demonstrates that TBT induces the expression of adipogenesis- and apoptosis-related genes in the ovary leading to apoptosis in the ovarian follicles. These results suggest that the increased expression of adipogenesis-related genes in the ovary by TBT exposure might induce apoptosis resulting in a loss of ovarian function.
Subject(s)
Animals , Female , Rats , Adipogenesis , Apoptosis , DNA Nucleotidylexotransferase , In Situ Nick-End Labeling , Ovarian Follicle , Ovary , PPAR gamma , Rats, Sprague-Dawley , Real-Time Polymerase Chain Reaction , Receptors, Tumor Necrosis Factor, Type I , RNA , Sesame Oil , Trialkyltin Compounds , Tumor Necrosis Factor-alphaABSTRACT
OBJECTIVE: Tributyltin (TBT), an endocrine disrupting chemical, has been reported to decrease ovarian function by causing apoptosis in the ovary, but the mechanism is not fully understood. Therefore, we examined whether TBT increases the expression of adipogenesis-related genes in the ovary and the increased expression of these genes is associated with apoptosis induction. METHODS: Three-week-old Sprague-Dawley rats were orally administered TBT (1 or 10 mg/kg body weight) or sesame oil as a control for 7 days. The ovaries were obtained and weighed on day 8, and then they were fixed for terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) or frozen for RNA extraction. Using the total RNA of the ovaries, adipogenesis- and apoptosis-related genes were analyzed by real-time polymerase chain reaction (PCR). RESULTS: The ovarian weight was significantly decreased in rats administered 10 mg/kg TBT compared to that in control rats. As determined by the TUNEL assay, the number of apoptotic follicles in ovary was significantly increased in rats administered 10 mg/kg TBT. The real-time PCR results showed that the expression of adipogenesis-related genes such as PPARgamma, aP2, CD36, and PEPCK was increased after TBT administration. In addition, apoptosis-related genes such as TNFalpha and TNFR1 were expressed more in the TBT-administered rats compared with the control rats. CONCLUSION: The present study demonstrates that TBT induces the expression of adipogenesis- and apoptosis-related genes in the ovary leading to apoptosis in the ovarian follicles. These results suggest that the increased expression of adipogenesis-related genes in the ovary by TBT exposure might induce apoptosis resulting in a loss of ovarian function.