Ruxolitinib induces apoptosis and pyroptosis of anaplastic thyroid cancer via the transcriptional inhibition of DRP1-mediated mitochondrial fission.

Anaplastic thyroid carcinoma (ATC) has a 100% disease-specific mortality rate. The JAK1/2-STAT3 pathway presents a promising target for treating hematologic and solid tumors. However, it is unknown whether the JAK1/2-STAT3 pathway is activated in ATC, and the anti-cancer effects and the mechanism of action of its inhibitor, ruxolitinib (Ruxo, a clinical JAK1/2 inhibitor), remain elusive. Our data indicated that the JAK1/2-STAT3 signaling pathway is significantly upregulated in ATC tumor tissues than in normal thyroid and papillary thyroid cancer tissues. Apoptosis and GSDME-pyroptosis were observed in ATC cells following the in vitro and in vivo administration of Ruxo. Mechanistically, Ruxo suppresses the phosphorylation of STAT3, resulting in the repression of DRP1 transactivation and causing mitochondrial fission deficiency. This deficiency is essential for activating caspase 9/3-dependent apoptosis and GSDME-mediated pyroptosis within ATC cells. In conclusion, our findings indicate DRP1 is directly regulated and transactivated by STAT3; this exhibits a novel and crucial aspect of JAK1/2-STAT3 on the regulation of mitochondrial dynamics. In ATC, the transcriptional inhibition of DRP1 by Ruxo hampered mitochondrial division and triggered apoptosis and GSDME-pyroptosis through caspase 9/3-dependent mechanisms. These results provide compelling evidence for the potential therapeutic effectiveness of Ruxo in treating ATC.

Prolonged small vessel vasculitis with colon mucosal inflammation as first manifestations of Behçet's disease.

Behçet's disease is a chronic, relapsing, systemic vasculitis of unknown aetiology. Patients present manifestations of gastrointestinal complications, including mouth lesions, small and large intestinal lesions, and vascular lesions in the abdomen. In some cases, the intestinal ulcers of patients with Behçet's disease are indistinguishable from those of Crohn's disease, tuberculosis, vasculitis and other diseases. In this article, we present a case of atypical Behçet's disease with a complicated medical history and multisystem damage, for the purpose of better management of this disease.

Exome sequencing revealed novel germline mutations in Chinese Peutz-Jeghers syndrome patients.

BACKGROUND AND AIMS: Peutz-Jeghers Syndrome (PJS) is an autosomal dominant disorder which predisposes to the development of various cancers. Germline mutation in the serine/threonine kinase 11 gene (STK11) is known as one of the major causes of PJS. However, a notable proportion of PJS samples do not carry any mutation in STK11, suggesting possible genetic heterogeneity in the disease and the existence of other causative variants. METHODS AND RESULTS: In order to identify other germline variants in the coding regions of the genome that are associated with PJS, we performed exome sequencing in three Chinese individuals with PJS and identified 16 common germline variants (12 protein-coding including STK11, 4 in pre-microRNAs). We further validated protein-coding variants in six PJS individuals (three with wild-type STK11) and predicted the functional impact. As result, we found that 7 coding variants are likely to have functional impacts. Especially, we identified 2 new germline variants which are represented in all six PJS samples and are independent of STK11 mutation. CONCLUSIONS: Our study provided an exomic view of PJS. The germline variants identified in our analysis may help to resolve the complex genetic background of the disease and thus lead to the discovery of novel causative variants of PJS.

Inhibitory effect of ARHI on pancreatic cancer cells and NF-κB activity.

The aim of this study was to investigate the effect of aplasia ras homolog member I (ARHI) on proliferation, apoptosis and the cell cycle in the pancreatic cancer cell line PANC-1. The study also aimed to examine the effect of ARHI on the activity of the nuclear factor (NF)-κB and to determine whether ARHI acts as a tumor suppressor in the development of pancreatic cancer by inhibiting the activity of NF-κB. A pIRES2­EGFP­ARHI vector, constructed by reverse transcrition (RT)­PCR, was transiently transfected into the PANC-1 cells and analyzed for the expression of the ARHI protein by western blotting. A MTT assay was used to quantify cell proliferation, and apoptosis was analyzed by flow cytometry. The NF­κB signaling pathway, specifically the pathway using the nuclear phosphorylated p65 isoform, was analyzed by western blotting. Expression of the ARHI protein was detected by western blotting subsequent to the PANC-1 cells being transiently transfected with the pIRES2­EGFP­ARHI construct. Cell proliferation was strongly inhibited in the PANC-1 cells transfected with pIRES2­EGFP­ARHI. The cell cycle assays indicated an increase in the number of cells at the G0/G1 phase and a decrease in the cells at the S phase, but the difference was not significant (P>0.05). Time course studies also indicated a marked increase in the apoptotic index following transient transfection, as well as a gradual decrease in the expression of the nuclear phosphorylated p65 protein. ARHI acts as a tumor suppressor by downregulating the NF­κB signaling pathway, which results in the inhibition of cell proliferation, apoptosis and the cell cycle in the pancreatic tumor PANC-1 cell line.

Aplasia ras homolog member I is downregulated in gastric cancer and silencing its expression promotes cell growth in vitro.

BACKGROUND AND AIM: Aplasia ras homolog member I (ARHI) is a maternally imprinted tumor suppressor gene. ARHI protein is widely expressed in many types of human tissues; however, its expression is frequently reduced or absent in various tumors and plays a tumor suppressor role for in vitro study. In this study, we investigated the expression level of ARHI in gastric cancer in order to investigate the function of ARHI and signaling pathways that might be linked during gastric cancer development. METHODS: ARHI mRNA and protein expression levels were analyzed in primary gastric cancer tissues, adjacent noncancerous gastric tissues and gastric cancer cell lines using semi-quantitative polymerase chain reaction, western blotting and immunohistochemistry, respectively. RESULTS: Our results showed that both mRNA and protein expression levels of the ARHI gene were significantly downregulated (P < 0.05) in gastric cancer tissues and cell lines compared to the corresponding normal control groups. The protein expression level of ARHI was not associated with age, gender, location of tumor, tumor size or metastasis in patients with gastric cancer. However, a significant correlation between the level of ARHI protein expression and the degree of tumor differentiation and Tumor-Node-Metastasis stage was observed (P < 0.05). Furthermore, results of the methyl thiazolyl tetrazolium and Transwell assays and flow cytometric analysis showed increased cell proliferation, migration and anti-apoptotic capacities in the well-differentiated gastric cancer MKN-28 cell line, which has stably silenced ARHI protein expression. CONCLUSION: Our data indicate that ARHI expression is downregulated in human gastric cancer and it may be a novel tumor suppressive target for gastric cancer therapy.

Factor X Shanghai and disruption of translocation to the endoplasmic reticulum.

BACKGROUND AND OBJECTIVES: Most secreted proteins, including coagulation factor X (FX), are synthesized with a signal peptide, which is necessary for targeting the nascent polypeptide into the endoplasmic reticulum. Characterization of naturally occurring mutations may provide insights into the functional roles of the amino acids in the signal peptide. DESIGN AND METHODS: A 52-year old male patient with type I FX deficiency was studied. Mutations were searched for by FX gene (F10) sequencing. The wild-type and the mutant FX proteins were expressed in transfected cells and then immunological assays were performed. Pulse-chase experiments and cell-free expression studies were conducted to determine the cellular fate of the mutant FX molecules. RESULTS: The patient we studied was homozygous for a substitution of arginine for serine at codon -30 in the signal sequence of F10. Immunoassays detected low FX antigen levels in both the conditioned media and lysates of the cells expressing the mutant protein. Pulse-chase analysis showed that only trace amounts of the mutant FX protein were detectable in the conditioned media, and that the mutant molecules did not accumulate inside the cells either. The results of cell-free expression studies showed that although the transcription and translation of the mutant construct were normal, no post-translational processing, such as N-linked glycosylation, occurred in the presence of microsomes. INTERPRETATION AND CONCLUSIONS: These findings suggest that substitution of a neutral polar amino acid, serine by arginine, in the hydrophobic core of FX signal peptide severely impairs the ability of the protein to enter the endoplasmic reticulum and results in FX deficiency.

Biochemical activity and gene analysis of inherited protein C and antithrombin deficiency in two Chinese pedigrees.

BACKGROUND: We identified the gene mutations in two Chinese pedigree of type I hereditary protein C deficiency and type I hereditary antithrombin deficiency. METHODS: The plasma level of protein C activity (PC:A), protein C antigen (PC:Ag), protein S activity, antithrombin activity (AT:A) and antithrombin antigen (AT:Ag) of propositi and two family members were detected using ELISA and chromogenic assay, respectively. All exons and intron-exon boundaries of protein C gene and antithrombin gene were analyzed by direct sequencing of the corresponding amplified PCR products in DNA from the propositus. RESULTS: The plasma PC:A and PC:Ag of propositus 1 was 26% and 1.43 mg/dl, respectively. The PC:Ag and PC:A of his father were normal. The decreased PC:A level was seen in his mother and 4 of his maternal pedigree. PS:A and AT:A were all normal in pedigree 1 members. A C5498T heterozygous mutation in exon 3 of protein C gene, resulting in the substitution of Arg for Trp at the 15th amino acid, was identified in propositus 1 and 8 of his relatives. The plasma AT:A and AT:Ag of propositus 2 was 48.6% and 10.4 mg/dl, respectively. The reduced AT:A and AT:Ag levels were found in his father and 5 of paternal pedigree. PC:A, PC:Ag and PS:A were all in normal range. A heterozygous 13387-9G deletion in exon 6 of antithrombin gene was identified in propositus 2. This mutation introduced a frameshift and a premature stop at codon 426 and existed in 6 members of pedigree 2. CONCLUSION: The C5498T heterozygous mutation in exon 3 of protein C gene, first reported in China, leads to type I hereditary protein C deficiency. The 13387-9G deletion, a novel mutation, can cause antithrombin deficiency and thrombosis.

[Comparison and analysis of the clinical features of different types of gastrointestinal cancers].

OBJECTIVE: To analysis the clinical features of gastrointestinal (GI) carcinoid tumor in different pathological types, and to improve the level of its diagnosis and treatment. METHODS: Retrospectively analysis 36 cases of GI carcinoid in Peking Union Medical College Hospital from 1982 to 2003, according to the International Classification of Disease for Oncology (ICD-O). The 36 cases were divided into carcinoid group and malignant carcinoid group. Their clinical presentation, metastasis, age, its ratio in gastrointestinal endocrine and non-endocrine tumor were compared. RESULTS: (1) Ratio: the ratio of GI carcinoid in digestive system non-endocrine tumor was 0.35%, in endocrine tumor was 10.20%. (2) Age: the mean age of the malignant carcinoid group was (55.8 +/- 12.8) years old and carcinoid group was (45.1 +/- 12.0). The age of the malignant carcinoid group is significantly higher than that of the carcinoid group. (3) Sites: the rectum carcinoid (63%) was the most common site of the overall GI carcinoid, the gastric (35%) and colonic (25%) carcinoid in the malignant carcinoid group were found more than that in carcinoid group. (4) Metastasis: the lymphonode and liver (60%) were most common sites of malignant carcinoid tumor. The ratio of metastasis from stomach and colon was higher than that from the other gastrointestinal sites. (5) DIAGNOSTIC METHODS: most of the GI carcinoid tumors were diagnosed by the colonoscopy. The rectal touch should not be neglected. (6) Carcinoid syndrome: The incidence of carcinoid syndrome was quite low and often occurred in malignant carcinoid tumor. CONCLUSIONS: The overall incidence of GI carcinoid tumor makes up 0.35% of gastrointestinal tumor. It is not common disease but not rare. The rectum is most common site of carcinoid tumor. Most of the gastric and colonic carcinoid tumor was belonging to malignant. The mean age of malignant carcinoid tumor was older with the metastasis of lymphonode and liver. The carcinoid syndrome often occurred in malignant carcinoid tumor.

[Type I hereditary protein C deficiency due to C5498T mutation in protein C gene].

OBJECTIVE: To identify the gene mutation in a Chinese pedigree of type I hereditary protein C deficiency. METHODS: The plasma levels of protein C activity (PC:A), protein C antigen (PC:Ag), protein S activity, and anti-thrombin activity (AT:A) of the propositus, male, aged 7, and 11 members of the pedigree were detected using ELISA and chromogenic assay respectively. All of the nine exons and intron-exon boundaries of protein C gene of the propositus were analyzed by direct sequencing of the corresponding amplified PCR products in DNA from the propositus. Restriction enzyme site analysis was used to confirm the mutation. RESULTS: The plasma concentrations of protein C activity and antigen of the propositus were 26% and 1.43 g/L respectively. The PC:Ag and PC:A of his father were normal. Decreased PC:A level was seen in his mother and 4 of his maternal pedigree. PS:A and AT:A were all normal in all of the pedigree members. A C5498T heterozygous mutation in exon 3, resulting in the substitution of Arg for Trp at the 15th amino acid, was identified in the propositus and 8 of his relatives. This mutation was confirmed by restriction enzyme site analysis. Mutations C/T at position 2405, A/G at position 2418, and A/T at position 2583 in the protein C promoter region were confirmed in the propositus and all members of the pedigree. CONCLUSION: C5498T heterozygous mutation in exon 3 of protein C gene, first reported in China, leads to type I hereditary.

[Molecular mechanisms of two novel mutations of factor XIII gene resulting in hereditary coagulation deficiency].

OBJECTIVE: To investigate the mechanisms of two novel missense mutations of factor XIIIA subunit gene (Arg77-->Cys,Ser413-->Trp) in the pathogenesis of hereditary factor XIII deficiency. METHODS: Site-directed mutagenesis was conducted to obtain 2 mutant human XIII A recombinant plasmids, mut-PCI/FXIIIA. Normal wild type factor XIII A recombinant plasmid, wt-PCI/FXIIIA, and mut-PCI/FXIIIA, were transfected into cultured COS7 cells line, renal fibroid cell of African green monkey using Superfect reagent respectively, The expression levels of DNA, RNA and protein of human factor XIII, both wild type and mutant, were detected by PCR, RT-PCR and Western blotting. Pulse-chase experiment was used to look into the changing of factor XIII A in the cytoplasm. Factor XIIIA activity was assayed by Biotin-pentylamine incorporation technique. RESULTS: The mRNA levels of the two mutants in transfected cells were similar to that of the wild type factor XIIIA. But the amount of mutant factor XIIIA protein and its activity in cells decreased markedly, even disappeared. Pulse-chase experiment revealed that at the two mutants existed chase time 0.5 h and 1 h considerable amounts in cells and then disappeared rapidly later. CONCLUSION: The 2 mutations of the factor XIIIA cause the instability, degradation, and rapid disappearance of FXIIIA in cytoplasm, thus resulting in hereditary factor XIII deficiency.