Biological and clinical aspects of HPV-related cancers

Cancer-related diseases represent the second overall cause of death worldwide.Human papilloma virus(HPV)is an infectious agent which is mainly sexually transmitted and may lead to HPV-associated cancers in both men and women.Almost all cervical cancers are HPV-associated,however,an increasing number of head and neck cancers(HNCs),especially oropharyngeal cancer,can be linked to HPV infection.Moreover,anogenital cancers,including vaginal,vulvar,penial,and anal cancers,represent a subset of HPVrelated cancers.Whereas testing and prevention of cervical cancer have significantly improved over past decades,anogenital cancers remain more difficult to confirm.Current clinical trials including patients with HPV-related cancers focus on finding proper testing for all HPV-associated cancers as well as improve the currently applied treatments.The HPV viral oncoproteins,E6 and E7,lead to degradation of,respectively,p53 and pRb resulting in entering the S phase without G1 arrest.These high-risk HPV viral oncogenes alter numerous cellular processes,including DNA repair,angiogenesis,and/or apoptosis,which eventually result in carcinogenesis.Additionally,a comprehensive analysis of gene expression and alteration among a panel of DNA double strand breaks(DSB)repair genes in HPV-negative and HPV-positive HNC cancers reveals differences pointing to HPV-dependent modifications of DNA repair processes in these cancers.In this review,we discuss the current knowledge regarding HPV-related cancers,current screening,and treatment options as well as DNA damage response-related biological aspects of the HPV infection and clinical trials.

Predictive factors for the local recurrence and distant metastasis of phyllodes tumors of the breast: a retrospective analysis of 192 cases at a single center

The local recurrence rate of phyllodes tumors of the breast varies widely among different subtypes, and distant metastasis is associated with poor survival. This study aimed to identify factors that are predictive of local recurrence-free survival(LRFS), distant metastasis-free survival(DMFS), and overall survival(OS) in patients with phyllodes tumors of the breast. Clinical data of all patients with a phyllodes tumor of the breast(n = 192) treated at Sun Yat-sen University Cancer Center between March 1997 and December 2012 were reviewed. The Pearson χ2 test was used to investigate the relationship between clinical features of patients and histotypes of tumors. Univariate and multivariate Cox regression analyses were performed to identify factors that are predictive of LRFS, DMFS, and OS. In total, 31(16.1%) patients developed local recurrence, and 12(6.3%) developed distant metastasis. For the patients who developed local recurrence, the median age at the diagnosis of primary tumor was 33 years(range, 17-56 years), and the median size of primary tumor was 6.0 cm(range, 0.8-18 cm). For patients who developed distant metastasis, the median age at the diagnosis of primary tumor was 46 years(range, 24-68 years), and the median size of primary tumor was 5.0 cm(range, 0.8-18 cm). In univariate analysis, age, size, hemorrhage, and margin status were found to be predictive factors for LRFS(P = 0.009, 0.024, 0.004, and 0.001, respectively), whereas histotype, epithelial hyperplasia, margin status, and local recurrence were predictors of DMFS(P = 0.001, 0.007, 0.007, and < 0.001, respectively). In multivariate analysis, independent prognostic factors for LRFS included age [hazard ratio(HR) = 3.045, P = 0.005], tumor size(HR = 2.668, P = 0.013), histotype(HR = 1.715, P = 0.017), and margin status(HR = 4.530, P< 0.001). Histotype(DMFS: HR = 4.409, P = 0.002; OS: HR = 4.194, P = 0.003) and margin status(DMFS: HR = 2.581, P = 0.013; OS: HR = 2.507, P = 0.020) were independent predictors of both DMFS and OS. In this cohort, younger age, a larger tumor size, a higher tumor grade, and positive margins were associated with lower rates of LRFS. Histotype and margin status were found to be independent predictors of DMFS and OS.

PRMT5 regulates Golgi apparatus structure through methylation of the golgin GM130

Maintenance of the Golgi apparatus （GA） structure and function depends on Golgi matrix proteins. The posttranslational modification of Golgi proteins such as phosphorylation of members of the golgin and GRASP families is important for determining Golgi architecture. Some Golgi proteins including golgin-84 are also known to be methylated, but the function of golgin methylation remains unclear. Here, we show that the protein arginine methyltransferase 5 （PRMT5） localizes to the GA and forms complexes with several components involved in GA ribbon formation and vesicle tethering. PRMT5 interacts with the golgin GM130, and depletion of PRMT5 causes defects in Golgi ribbon formation. Furthermore, PRMT5 methylates N-terminal arginines in GM130, and such arginine methylation appears critical for GA ribbon formation. Our findings reveal a molecular mechanism by which PRMT5-dependent arginine methylation of GM130 controls the maintenance of GA architecture.

Detection of RASSF1A promoter hypermethylation in serum from gastric and colorectal adenocarcinoma patients

AIM：To evaluate the diagnostic role of serum RASSF1A promoter hypermethylation in gastric and colorectal adenocarcinoma. METHODS：Methylation-specific polymerase chain reaction （MSPCR） was used to examine the promoter methylation status of the serum RASSF1A gene in 47 gastric adenocarcinoma patients, 45 colorectal adenocarcinoma patients, 60 patients with benign gastrointestinal disease （30 with benign gastric disease and 30 with benign colorectal disease）, and 30 healthy donor controls. Apaired study of RASSF1A promoter methylation status in primary tumor, adjacent normal tissue, and postopertive serum were conducted in 25 gastric and colorectal adenocarcinoma patients who later were underwent surgical therapy. RESULTS：The frequencies of detection of serum RASSF1A promoter hypermethylation in gastric （34.0%） and colorectal （28.9%） adenocarcinoma patients were significantly higher than those in patients with benign gastric （3.3%） or colorectal （6.7%） disease or in healthy donors （0%） （P 〈 0.01）. The methylation status of RASSF1A promoter in serum samples was consistent with that in paired primary tumors, and the MSPCR results for RASSF1A promoter methylation status in paired preoperative samples were consistent with those in postoperative serum samples. The serum RASSF1A promoter hypermethylation did not correlate with patient sex, age, tumor differentiation grade, surgical therapy, or serum carcinoembryonic antigen level. Although the serum RASSF1A promoter hypermethylation frequency tended to be higher in patients with distant metastases, there was no correlation between methylation status and metastasis. CONCLUSION：Aberrant CpG island methylation within the promoter region of RASSF1A is a promising biomarker for gastric and colorectal cancer.

Temporal profiles of synaptic plasticity-related signals in adult mouse hippocampus with methotrexate treatment

Methotrexate, which is used to treat many malignancies and autoimmune diseases, affects brain functions including hippocampal-dependent memory function. However, the precise mechanisms underlying methotrexate-induced hippocampal dysfunction are poorly understood. To evaluate temporal changes in synaptic plasticity-related signals, the expression and activity of N-methyI-D-aspartic acid receptor 1, calcium/calmodulin-dependent protein kinase II, extracellular signal-regulated kinase 1/2, cAMP responsive element-binding protein, glutamate receptor 1, brain-derived neurotrophic factor, and glial cell line-derived neurotrophic factor were examined in the hippocampi of adult C57BL/6 mice after methotrexate （40 mg/kg） intraperitoneal injection. Western blot analysis showed biphasic changes in synaptic plasticity-related signals in adult hippocampi following methotrexate treatment. N-methyI-D-aspartic acid receptor 1, calcium/calmodulin-dependent protein kinase II, and glutamate receptor 1 were acutely activated during the early phase （1 day post-injection）, while extracellular signal-regulated kinase 1/2 and cAMP responsive element-binding protein activation showed biphasic increases during the eady （1 day post-injection） and late phases （7-14 days post-injection）. Brain-derived neurotrophic factor and glial cell line-derived neurotrophic factor expression increased significantly during the late phase （7-14 days post-injection）. Therefore, methotrexate treatment affects synaptic plasticity-related signals in the adult mouse hippocampus, suggesting that changes in synaptic plasticity-related signals may be associated with neuronal survival and plasticity-related cellular remodeling.

电离辐射诱导小鼠小肠隐窝和绒毛的基因表达分析

目的通过基因表达的芯片分析方法,观察电离辐射引起的小鼠小肠上皮隐窝和绒毛基因表达的改变,探讨隐窝细胞的DNA损伤和修复、细胞周期调控的特点。方法 20只5周龄C57/BL6小鼠雄性20～22 g,随机分组,对照组不经电离辐照,处理组经12 Gy电离辐射全身照射后,于4、8、24 h分离小肠隐窝和绒毛上皮细胞,用cDNA表达谱芯片分别检测隐窝和绒毛基因表达的动态变化,对上调或下调的基因进行聚类分析,并重点对DNA损伤修复相关和细胞周期相关基因进行分析。结果与对照组相比上调或下调2倍以上的基因(P<0.01)经聚类分析被归属为各细胞信号通路,其中主要涉及p53通路、MAPK通路、凋亡、细胞周期以及免疫反应(P<0.05),将P值排序发现p53通路、MAPK通路对隐窝的调控更为明显。各DNA修复途径代表基因在隐窝和绒毛中均有不同程度的上调表达,且与细胞周期的变化相一致。基因表达特点提示隐窝细胞以准确性高的方式(核苷酸外切修复、同源重组)进行DNA损伤修复,而绒毛细胞则以快速但易发生错误修复的方式(错配修复)恢复基因的完整性。结论 电离辐射诱导的DNA损伤反应与细胞分化程度相关,隐窝细胞对损伤更敏感。

COVID-19 and its effects on the digestive system

Coronavirus disease 2019(COVID-19)is caused by infection of the coronavirus severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)with typical respiratory symptoms.SARS-CoV-2 invades not only the respiratory system,but also other organs expressing the cell surface receptor angiotensin converting enzyme 2.In particular,the digestive system is a susceptible target of SARS-CoV-2.Gastrointestinal symptoms of COVID-19 include anorexia,nausea,vomiting,diarrhea,abdominal pain,and liver damage.Patients with digestive damage have a greater chance of progressing to severe or critical illness,a poorer prognosis,and a higher risk of death.This paper aims to summarize the digestive system symptoms of COVID-19 and discuss fecal-oral contagion of SARS-CoV-2.It also describes the characteristics of inflammatory bowel disease patients with SARSCoV-2 infection and discusses precautions for preventing SARS-CoV-2 infection during gastrointestinal endoscopy procedures.Improved attention to digestive system abnormalities and gastrointestinal symptoms of COVID-19 patients may aid health care providers in the process of clinical diagnosis,treatment,and epidemic prevention and control.

位于氧化还原稳态调控和癌症营养依赖性十字路口的氨基酸转运蛋白SLC7A11/xCT

癌细胞经常会上调营养转运蛋白的表达,以满足它们日益增加的生物合成和生物能量需求,并维持氧化还原的动态平衡。在人类癌症中有一种经常过表达的营养转运蛋白,是胱氨酸/谷氨酸逆向转运蛋白溶质载体家族7成员11(solute carrier family 7 member 11,SLC7A11,也称为xCT)。SLC7A11促进胱氨酸摄取和谷胱甘肽生物合成,从而防止氧化应激和细胞铁死亡。最近的研究意外地揭示了SLC7A11在谷氨酰胺代谢中也起着关键作用,并调节癌细胞的葡萄糖和谷氨酰胺依赖性。本文综述了SLC7A11在调节癌细胞抗氧化反应和营养依赖中的作用,探讨了SLC7A11在肿瘤代谢中的调控作用,并提出了这一新兴研究领域中有待进一步研究的关键问题。对癌症代谢中SLC7A11的更深入了解可能会为这种重要的氨基酸转运蛋白靶向癌症治疗提供新的治疗机会。

A highly degradable Mg-Al-Ca alloy with superior anti-tumor efficacy

Molecule hydrogen(H_(2)) has been used to suppress tumor growth. To employ the H_(2) therapy, it is necessary to use a proper agent for continuous generation of H_(2). As a biodegradable metal, magnesium(Mg) generates H_(2) in an aqueous environment, but the H_(2) release rate is still too low. Here, we design a Mg-Al-Ca(AX) alloy that degrades very rapidly due to the presence of a secondary phase Al_(2)Ca. Having a reduction potential much higher than Mg and any other Mg-based secondary phases, Al_(2)Ca accelerates the corrosion of the Mg matrix by a micro-galvanic process. Al_(2)Ca also enhances the strength and ductility of the AX alloy. AX alloy rods show better anti-tumor efficacy than pure Mg rods in vivo. Moreover, implanted AX alloy rods can be heated under an alternating magnetic field to suppress large-size tumors.This work suggests that the H_(2) therapy using highly degradable Mg alloys may provide an effective cancer treatment.

Proteomic analysis of ferroptosis pathways reveals a role of CEPT1 in suppressing ferroptosis

Ferroptosis has been recognized as a unique cell death modality driven by excessive lipid peroxidation and unbalanced cellular metabolism.In this study,we established a protein interaction landscape for ferroptosis pathways through proteomic analyses,and identified choline/ethanolamine phosphotransferase 1(CEPT1)as a lysophosphatidylcholine acyltransferase 3(LPCAT3)-interacting protein that regulates LPCAT3 protein stability.In contrast to its known role in promoting phospholipid synthesis,we showed that CEPT1 suppresses ferroptosis potentially by interacting with phospholipases and breaking down certain pro-ferroptotic polyunsaturated fatty acid(PUFA)-containing phospholipids.Together,our study reveals a previously unrecognized role of CEPT1 in suppressing ferroptosis.

Amino acid transporter SLC7A11/ xCT at the crossroads of regulating redox homeostasis and nutrient dependency of cancer

Cancer cells often upregulate nutrient transporters to fulfill their increased biosynthetic and bioenergetic needs,and to maintain redox homeostasis.One nutrient transporter frequently overexpressed in human cancers is the cystine/glutamate antiporter solute carrier family 7 member 11(SLC7A11;also known as xCT).SLC7A11 promotes cystine uptake and glutathione biosynthesis,resulting in protection from oxidative stress and ferroptotic cell death.Recent studies have unexpectedly revealed that SLC7A11 also plays critical roles in glutamine metabolism and regulates the glucose and glutamine dependency of cancer cells.This review discusses the roles of SLC7A11 in regulating the anti-oxidant response and nutrient dependency of cancer cells,explores our current understanding of SLC7A11 regulation in cancer metabolism,and highlights key open questions for future studies in this emerging research area.A deeper understanding of SLC7A11 in cancer metabolism may identify new therapeutic opportunities to target this important amino acid transporter for cancer treatment.

Formation and repair of DNA-protein crosslink damage

DNA is constantly exposed to a wide array of genotoxic agents, generating a variety of forms of DNA damage. DNA-protein crosslinks(DPCs)—the covalent linkage of proteins with a DNA strand—are one of the most deleterious and understudied forms of DNA damage, posing as steric blockades to transcription and replication. If not properly repaired, these lesions can lead to mutations, genomic instability, and cell death. DPCs can be induced endogenously or through environmental carcinogens and chemotherapeutic agents. Endogenously, DPCs are commonly derived through reactions with aldehydes, as well as through trapping of various enzymatic intermediates onto the DNA. Proteolytic cleavage of the protein moiety of a DPC is a general strategy for removing the lesion. This can be accomplished through a DPC-specific protease and and/or proteasome-mediated degradation.Nucleotide excision repair and homologous recombination are each involved in repairing DPCs, with their respective roles likely dependent on the nature and size of the adduct. The Fanconi anemia pathway may also have a role in processing DPC repair intermediates. In this review, we discuss how these lesions are formed, strategies and mechanisms for their removal, and diseases associated with defective DPC repair.

Ferroptosis as an important driver of lupus

Systemic lupus erythematosus(SLE),the most common form of lupus,is a chronic autoimmune disorder characterized by a global loss of self-tolerance and hyper-activation of both innate and adaptive immune systems(Kaul et al.,2016).Neutrophils,the most abundant leukocytes in human blood,have a critical role in maintaining immune surveillance and tissue homeostasis,and its dysregulation is of high relevance to SLE(Ricklin et al.,2010).In patients with SLE,accelerated neutrophil death and the deficiency in clearing dying neutrophils cause nuclear and cytoplasmic antigen exposure,excessive production of type I interferon(IFN),and neutrophil extracellular trap(NET)release,subsequently inducing autoimmune responses(Garcia-Romo et al.,2011).Dysregulated neutrophil death is believed to be a major cause of SLE;however,the underlying mechanism of neutrophil death in SLE is not well-defined.

The multiple fronts of conquering cancer

Understanding and treating tumors have been a long journey for mankind since the dawn of the 1st century when the Greek terms ＂carcinoma＂ and ＂onco-＂ emerged to document the recognition of tumors. It was not until the end of World War II when the first chemotherapy was attempted using nitrogen mustard and succeeded in curtailing the tumor burden of a lymphoma patient （Gilman, 1963; Goodman and Wintrobe, 1946）. Today, three types of cancer treatment （surgical resection aside） constitute the main front of fighting cancer： chemotherapy, targeted therapy, radiation therapy, and immunotherapy.

Mass spectrometry-based protein-protein interaction techniques and their applications in studies of DNA damage repair

Proteins are major functional units that are tightly connected to form complex and dynamic networks.These networks enable cells and organisms to operate properly and respond efficiently to environmental cues.Over the past decades,many biochemical methods have been developed to search for protein-binding partners in order to understand how protein networks are constructed and connected.At the same time,rapid development in proteomics and mass spectrometry(MS)techniques makes it possible to identify interacting proteins and build comprehensive protein-protein interaction networks.The resulting interactomes and networks have proven informative in the investigation of biological functions,such as in the field of DNA damage repair.In recent years,a number of proteins involved in DNA damage response and DNA repair pathways have been uncovered with MS-based protein-protein interaction studies.As the technologies for enriching associated proteins and MS become more sophisticated,the studies of protein-protein interactions are entering a new era.In this review,we summarize the strategies and recent developments for exploring protein-protein interaction.In addition,we discuss the application of these tools in the investigation of protein-protein interaction networks involved in DNA damage response and DNA repair.

Metabolic cell death in cancer:ferroptosis,cuproptosis,disulfidptosis,and beyond

Cell death resistance represents a hallmark of cancer.Recent studies have identified metabolic cell death as unique forms of regulated cell death resulting from an imbalance in the cellular metabolism.This review discusses the mechanisms of metabolic cell death—ferroptosis,cuproptosis,disulfidptosis,lysozincrosis,and alkaliptosis—and explores their potential in cancer therapy.Our review underscores the complexity of the metabolic cell death pathways and offers insights into innovative therapeutic avenues for cancer treatment.

Cystine transporter SLC7A11/xCT in cancer:ferroptosis,nutrient dependency,and cancer therapy

The cystine/glutamate antiporter SLC7A11(also commonly known as xCT)functions to import cystine for glutathione biosynthesis and antioxidant defense and is overexpressed in multiple human cancers.Recent studies revealed that SLC7A11 overexpression promotes tumor growth partly through suppressing ferroptosis,a form of regulated cell death induced by excessive lipid peroxidation.However,cancer cells with high expression of SLC7A11(SLC7A11^(high))also have to endure the significant cost associated with SLC7A11-mediated metabolic reprogramming,leading to glucose-and glutamine-dependency in SLC7A11^(high) cancer cells,which presents potential metabolic vulnerabilities for therapeutic targeting in SLC7A11^(high) cancer.In this review,we summarize diverse regulatory mechanisms of SLC7A11 in cancer,discuss ferroptosis-dependent and-independent functions of SLC7A11 in promoting tumor development,explore the mechanistic basis of SLC7A11-induced nutrient dependency in cancer cells,and conceptualize therapeutic strategies to target SLC7A11 in cancer treatment.This review will provide the foundation for further understanding SLC7A11 in ferroptosis,nutrient dependency,and tumor biology and for developing novel effective cancer therapies.

Ferroptosis,radiotherapy,and combination therapeutic strategies

Ferroptosis,an iron-dependent form of regulated cell death driven by peroxidative damages of polyunsatu-rated-fatty-acid-containing phospholipids in cellular membranes,has recently been revealed to play an important role in radiotherapy-induced cell death and tumor suppression,and to mediate the synergy between radiotherapy and immunotherapy.In this review,we summarize known as well as putative mechanisms underlying the crosstalk between radiotherapy and fer-roptosis,discuss the interactions between ferroptosis and other forms of regulated cell death induced by radiotherapy,and explore combination therapeutic strategies targeting ferroptosis in radiotherapy and immunotherapy.This review will provide important frameworks for future investigations of ferroptosis in cancer therapy.

Hypoxia inducible factor(HIF) in the tumor microenvironment：friend or foe？

Hypoxia acts as an important regulator of physiological and pathological processes. Hypoxia inducible factors(HIFs) are the central players involved in the cellular adaptation to hypoxia and are regulated by oxygen sensing EGLN prolyl hydroxylases.Hypoxia affects many aspects of cellular growth through both redox effects and through the stabilization of HIFs. The HIF isoforms likely have differential effects on tumor growth via alteration of metabolism, growth, and self-renewal and are likely highly context-dependent. In some tumors such as renal cell carcinoma, the EGLN/HIF axis appears to drive tumorigenesis,while in many others HIF1 and HIF2 may actually have a tumor suppressive role. An emerging role of HIF biology is its effects on the tumor microenvironment. The EGLN/HIF axis plays a key role in regulating the function of the various components of the tumor microenvironment, which include cancer-associated fibroblasts, endothelial cells, immune cells, and the extracellular matrix(ECM). Here, we discuss hypoxia and the diverse roles of HIFs in the setting of tumorigenesis and the maintenance of the tumor microenvironment as well as possible future directions of the field.

Recent progress in mass spectrometry proteomics for biomedical research

Proteins are the key players in many cellular processes. Their composition, trafficking, and interactions underlie the dynamic processes of life. Furthermore, diseases are frequently accompanied by malfunction of proteins at multiple levels. Understanding how biological processes are regulated at the protein level is critically important to understanding the molecular basis for diseases and often shed light on disease prevention, diagnosis, and treatment. With rapid advances in mass spectrometry(MS)instruments and experimental methodologies, MS-based proteomics has become a reliable and essential tool for elucidating biological processes at the protein level. Over the past decade, we have witnessed great expansion of knowledge of human diseases with the application of MS-based proteomic technologies, which has led to many exciting discoveries. Herein we review the recent progress in MS-based proteomics in biomedical research, including that in establishing disease-related proteomes and interactomes. We also discuss how this progress will benefit biomedical research and clinical diagnosis and treatment of disease.