Targeting TRMT5 suppresses hepatocellular carcinoma progression via inhibiting the HIF-1α pathways / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Accumulating evidence has confirmed the links between transfer RNA (tRNA) modifications and tumor progression. The present study is the first to explore the role of tRNA methyltransferase 5 (TRMT5), which catalyzes the m1G37 modification of mitochondrial tRNAs in hepatocellular carcinoma (HCC) progression. Here, based on bioinformatics and clinical analyses, we identified that TRMT5 expression was upregulated in HCC, which correlated with poor prognosis. Silencing TRMT5 attenuated HCC proliferation and metastasis both in vivo and in vitro, which may be partially explained by declined extracellular acidification rate (ECAR) and oxygen consumption rate (OCR). Mechanistically, we discovered that knockdown of TRMT5 inactivated the hypoxia-inducible factor-1 (HIF-1) signaling pathway by preventing HIF-1α stability through the enhancement of cellular oxygen content. Moreover, our data indicated that inhibition of TRMT5 sensitized HCC to doxorubicin by adjusting HIF-‍1α. In conclusion, our study revealed that targeting TRMT5 could inhibit HCC progression and increase the susceptibility of tumor cells to chemotherapy drugs. Thus, TRMT5 might be a carcinogenesis candidate gene that could serve as a potential target for HCC therapy.

Estrogen upregulates DNA2 expression through the PI3K-AKT pathway in endometrial carcinoma / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Endometrial cancer is the most common gynecological malignancy, affecting up to 3% of women at some point during their lifetime (Morice et al., 2016; Li and Wang, 2021). Based on the pathogenesis and biological behavioral characteristics, endometrial cancer can be divided into estrogen-dependent (I) and non-estrogen-dependent (II) types (Ulrich, 2011). Type I accounts for approximately 80% of cases, of which the majority are endometrioid carcinomas, and the remaining are mucinous adenocarcinomas (Setiawan et al., 2013). It is generally recognized that long-term stimulation by high estrogen levels with the lack of progesterone antagonism is the most important risk factor; meanwhile, there is no definite conclusion on the specific pathogenesis. The incidence of endometrial cancer has been on the rise during the past two decades (Constantine et al., 2019; Gao et al., 2022; Luo et al., 2022). Moreover, the development of assisted reproductive technology and antiprogestin therapy following breast cancer surgery has elevated the risk of developing type I endometrial cancer to a certain extent (Vassard et al., 2019). Therefore, investigating the influence of estrogen in type I endometrial cancer may provide novel concepts for risk assessment and adjuvant therapy, and at the same time, provide a basis for research on new drugs to treat endometrial cancer.

Luteolin suppresses oral carcinoma 3 (OC3) cell growth and migration via modulating polo-like kinase 1 (PLK1) expression and cellular energy metabolism / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Oral squamous cell carcinoma (OSCC) is a prevalent malignant tumor affecting the head and neck region (Leemans et al., 2018). It is often diagnosed at a later stage, leading to a poor prognosis (Muzaffar et al., 2021; Li et al., 2023). Despite advances in OSCC treatment, the overall 5-year survival rate of OSCC patients remains alarmingly low, falling below 50% (Jehn et al., 2019; Johnson et al., 2020). According to statistics, only 50% of patients with oral cancer can be treated with surgery. Once discovered, it is more frequently at an advanced stage. In addition, owing to the aggressively invasive and metastatic characteristics of OSCC, most patients die within one year of diagnosis. Hence, the pursuit of novel therapeutic drugs and treatments to improve the response of oral cancer to medication, along with a deeper understanding of their effects, remains crucial objectives in oral cancer research (Johnson et al., 2020; Bhat et al., 2021; Chen et al., 2023; Ruffin et al., 2023).

Tissue distribution and analysis of human umbilical cord mesenchymal stem cells in NOG mice following single intravenous injection / 中国实验动物学报

Objective To establish a quantitative polymerase chain reaction(PCR)method for the analysis of human-derived SRY DNA in mouse tissues,and to study the tissue distribution of human umbilical cord mesenchymal stem cells(HUCMSCs)in immunodeficient NOG mice after a single intravenous injection.Methods We established a quantitative PCR method for the analysis of human SRY DNA in mouse tissues,and validated the standard curve,linear range,accuracy,precision,and stability.Thirty-six NOG mice(18 male,18 female)were administered 3.5×107 HUCMSCs/kg by single intravenous injection.Six mice were then anesthetized and dissected after blood collection(EDTA anticoagulation)at 6,12,24,and 72 h,and at 1 and 2 weeks,respectively.DNA was extracted from lung,kidney,heart,liver,brain,spinal cord,stomach,small intestine,fat,skin,spleen,testis,uterus,and ovary tissues,and the distribution of HUCMSCs in each tissue was determined by the validated quantitative PCR method for detecting the human-derived SRY gene in mouse tissues.In addition,18 NOG mice(9 male,9 female)were divided into control(n = 6)and treatment groups(n = 12)injected intravenously with 0.9%sodium chloride and 3.5×107 cells/kg,respectively.Acute toxic reactions were observed during the administration period,and four animals were dissected at 72 h and at 2 and 4 weeks after administration to observe the gross organs.Mitochondrial protein expression was detected in paraffin sections of lung tissues by immunohistochemistry to analyze the colonization of HUCMSCs in lung tissues.Results The established RT-qPCR method for human-derived SRY DNA in mouse tissues met the validation criteria for each index.After a single intravenous injection in NOG mice,HUCMSCs were mainly distributed in the lungs and blood within 1 week after administration,with higher concentrations in lung tissues than in blood.The concentrations of HUCMSCs in lung tissue and blood remained relatively stable within 6～24 h and 6～72 h,respectively,and then decreased over time.The distribution of HUCMSCs in other tissues was not measured at all sampling points.The colonization result showed that HUCMSCs were detected in lungs 72 h after intravenous injection,but not at 2 and 4 weeks.No obvious acute toxicity was observed in NOG mice after single intravenous administration of HUCMSCs.Conclusions The above method for analyzing the distribution of HUCMSCs in mouse tissue is reliable and feasible.HUCMSCs were mainly distributed in lung and blood in NOG mice within 1 week after a single intravenous injection,and mainly colonized lung tissue at 72 h.A single intravenous administration of HUCMSCs has a good safety profile.