Simultaneous recovery of dual pathways for ammonia metabolism do not improve further detoxification of ammonia in HepG2 cells

BACKGROUND:Key enzyme deficiency in the dual-pathway of ammonia metabolism leads to low detoxification capacity of HepG2 cells.Previously,we established a HepG2/AFhGS cell line with overexpression of human glutamine synthetase(hGS) in pathway 1 and a HepG2/(hArgI+hOTC)4 cell line with overexpression of human arginase I(hArgI) and human ornithine transcarbamylase(hOTC) in pathway 2.The present study aimed to investigate whether simultaneous recovery of the two pathways contributes to the further improvement of ammonia detoxification in HepG2 cells.METHODS:We adopted a recombinant retrovirus carrying the hGS gene to infect HepG2/(hArgI+hOTC)4 cells and selected a new recombinant HepG2 cell line.The capacities of ammonia tolerance and detoxification in cells were detected by biochemical methods.Cell cycle PCR chip was used to assess the changes of gene expression.RESULTS:Introducing hGS into HepG2/(hArgI+hOTC)4 cells did not lead to hGS overexpression,but inhibited hArgI expression.The levels of synthetic glutamine and urea in HepG2/(hArgI+hOTC+AFhGS)1 cells were significantly lower than those in HepG2/(hArgI+hOTC)4 cells when cultured in the medium with 10 and 15 mmol/L glutamate(Glu) and with 60 and 180 mmol/L NH 4 Cl,respectively.In addition,the comparison of different cell growth showed that HepG2/AFhGS cells significantly lagged behind the other cells by the 5th and 7th day,indicating that introduction of hGS impedes HepG2 cell proliferation.Analysis of the mechanism suggested that the decreased expression of BCL2 played an important role.CONCLUSIONS:This study demonstrated that the recovery of two ammonia metabolic pathways in HepG2 cells is not helpful in increasing ammonia metabolism.The reinforcement of the pathway of urea metabolism is more important and valuable in improving the ammonia metabolism capacity in HepG2 cells.

Hepatic abscess caused by esophageal foreign body misdiagnosed as cystadenocarcinoma by magnetic resonance imaging:A case report

BACKGROUND Foreign bodies stuck in the throat and esophagus can be discharged through the digestive tract.Esophageal-lodged foreign bodies can cause secondary injury or detrimental response,with hepatic abscess being one such,albeit rare,outcome.Review and discussion of the few case reports on such instances will help to improve the overall understanding of such conditions and aid in differential diagnosis to improve patient outcome.CASE SUMMARY A 51-year-old female patient with pre-existing diabetes visited our hospital following a 15-d experience of chills and fever.Both plain and enhanced magnetic resonance imaging and color Doppler ultrasound examination of the liver and gallbladder revealed a space-occupying lesion in the caudate lobe of the liver(7.8 cm×6.0 cm×5.0 cm).Initially,a malignant tumor was suspected,but differential diagnosis was unable to exclude the possibility of hepatic abscess.Conservative anti-infection therapy produced a less than ideal outcome.Additional examination by hepatobiliary imaging with computed tomography suggested a foreign body present in the upper abdomen and hepatic abscess,and subsequent endoscopy revealed a sinus tract in the anterior wall of the duodenal bulb.Therefore,surgery was performed to remove the object(fishbone)and drain the abscess.After a 2-wk uneventful recovery,the patient was discharged.The final diagnosis was foreign body-induced hepatic abscess of the caudate lobe.CONCLUSION Differential diagnosis is important for hepatic masses,and systematic examination and physician awareness can aid in diagnosing and curing such rare conditions.

TCP1 regulates Wnt7b/β-catenin pathway through P53 to influence the proliferation and migration of hepatocellular carcinoma cells

Dear Editor,Molecular chaperones are critical mediators of oncogenesis and necessary for cell survival.1 The cytoplasmic chaperone TRiC(Tcomplex protein-1 ring complex,also known as CCT)comprises two back-to-back stacked rings,with each ring containing eight subunits(CCT1–CCT8).2 And the effects of CCT subunits on tumors may be different.However,the roles of the CCT1 subunit(also known as TCP1)in hepatocellular carcinoma(HCC)and its molecular mechanism have not been investigated thoroughly.Understanding these details can provide new ideas and strategies for treating HCC.