Inflammatory response in gastrointestinal cancers:Overview of six transmembrane epithelial antigens of the prostate in pathophysiology and clinical implications

Chronic inflammation is known to increase the risk of gastrointestinal cancers(GICs),the common solid tumors worldwide.Precancerous lesions,such as chronic atrophic inflammation and ulcers,are related to inflammatory responses in vivo and likely to occur in hyperplasia and tumorigenesis.Unfortunately,due to the lack of effective therapeutic targets,the prognosis of patients with GICs is still unsatisfactory.Interestingly,it is found that six transmembrane epithelial antigens of the prostate(STEAPs),a group of metal reductases,are significantly associated with the progression of malignancies,playing a crucial role in systemic metabolic homeostasis and inflammatory responses.The structure and functions of STEAPs suggest that they are closely related to intracellular oxidative stress,responding to inflammatory reactions.Under the imbalance status of abnormal oxidative stress,STEAP members are involved in cell transformation and the development of GICs by inhibiting or activating inflammatory process.This review focuses on STEAPs in GICs along with exploring their potential molecular regulatory mechanisms,with an aim to provide a theoretical basis for diagnosis and treatment strategies for patients suffering from these types of cancers.

Transmembrane serine protease 4 expression in the prognosis of radical resection for biliary tract cancer

BACKGROUND Recent advancements in biliary tract cancer(BTC)treatment have expanded beyond surgery to include adjuvant therapy,yet the prognosis remains poor.Identifying prognostic biomarkers could enhance the assessment of patients who have undergone radical resection for BTC.AIM To determine transmembrane serine protease 4(TMPRSS4)utility as a prognostic biomarker of radical resection for BTC.METHODS Medical records of patients who underwent radical resection for BTC,excluding intrahepatic cholangiocarcinoma,were retrospectively reviewed.The associations between TMPRSS4 expression and clinicopathological factors,overall survival,and recurrence-free survival were analyzed.RESULTS Among the 85 patients undergoing radical resection for BTC,46(54%)were TMPRSS4-positive.The TMPRSS4-positive group exhibited significantly higher preoperative carbohydrate antigen 19-9(CA19-9)values and greater lymphatic invasion than the TMPRSS4-negative group(P=0.019 and 0.039,respectively).Postoperative overall survival and recurrence-free survival were significantly worse in the TMPRSS4-positive group(median survival time:25.3 months vs not reached,P<0.001;median survival time:28.7 months vs not reached,P=0.043,respectively).Multivariate overall survival analysis indicated TMPRSS4 positivity,pT3/T4,and resection status R1 were independently associated with poor prognosis(P=0.032,0.035 and 0.030,respectively).TMPRSS4 positivity correlated with preoperative CA19-9 values≥37 U/mL and pathological tumor size≥30 mm(P=0.016 and 0.038,respectively).CONCLUSION TMPRSS4 is a potential prognostic biomarker of radical resection for BTC.

Understanding the role of transmembrane 9 superfamily member 1 in bladder cancer pathogenesis

In this editorial we comment on the article by Wei et al,published in the recent issue of the World Journal of Clinical Oncology.The authors investigated the role of Transmembrane 9 superfamily member 1(TM9SF1)protein in bladder cancer(BC)carcinogenesis.Lentiviral vectors were used to achieve silencing or overexpression of TM9SF1 gene in three BC cell lines.These cell lines were then subject to cell counting kit 8,wound-healing assay,transwell assay,and flow cytometry.Proliferation,migration,and invasion of BC cells were increased in cell lines subjected to TM9SF1 overexpression.TM9SF1 silencing inhibited proliferation,migration and invasion of BC cells.The authors conclude that TM9SF1 may be an oncogene in bladder cancer pathogenesis.

Potential role of transmembrane 9 superfamily member 1 as a biomarker in urothelial cancer

Bladder cancer is a urological tumor with high rates of recurrence despite recent advances in novel therapies.Many proteins involved in the molecular mechanisms are currently an enigma,especially the transmembrane 9 superfamily member 1 which has an unclear function.Wei et al published the function and mechanism of this protein,and showed that it could participate in the proliferation,migration and invasion of tumor cells in bladder cancer,therefore treatments directed against this protein may be beneficial in avoiding this condition.

Six transmembrane epithelial antigens of the prostate to illustrate inflammatory response in gastrointestinal cancers

Gastrointestinal cancer(GIC)is a common and widespread form of tumor,with colonoscopy and upper gastrointestinal endoscopy available to detect relevant precancerous polyps and lesions.However,many patients are already in the late stages when first diagnosed with such cancer,resulting in a poor prognosis.Thus,it is necessary to explore new methods and research directions in order to improve the treatment of GIC.Given the specific nature of the gastrointestinal tract,research should focus on the mechanisms of various inflammations and the interactions between food entering and exiting from the gastrointestinal tract and cancer cells.Interestingly,six transmembrane epithelial antigens of the prostates(STEAPs)have been found to be significantly linked to the progression of malignant tumors,associated with intracellular oxidative stress and playing a major role in inflammation with their structure and function.This paper explores the mechanism of STEAPs in the inflammatory response of GIC,providing a theoretical basis for the prevention and early intervention of GIC.The basic properties of the STEAP family as metal reductase are also explained.When it comes to intervention for GIC prevention,STEAPs can affect the activity of Fe^(3+),Cu^(2+) reductase and regulate metal ion uptake in vivo,participating in inflammation-related iron and copper homeostasis.Thus,the mechanism of STEAPs on inflammation is of important value in the prevention of GIC.

Low Level of Cystic Fibrosis Transmembrane Conductance Regulator Is Associated with Human Sperm Autophagy and Vitality

Low sperm motility is one of the main causes of male infertility. Cystic fibrosis transmembrane conductance regulator (CFTR, an anion channel protein) is related to the progressive motility of sperm. CFTR disruptor CFTRinh-172 or forskolin (FSK) in this study were used to treat human sperm separately, and the rates of sperm autophagy and progressive motility, mitochondrial membrane potential (MMP) and ATP concentration, and the expression levels of related factors were detected to explore their relationship. It was showed that sperms treated with CFTRinh-172 or FSK reduced the levels of cAMP, CFTR and PKA, but increased sperm autophagy rate, expression levels of AMPK and LC3B. However, reactive oxygen species content had no significant difference. It was indicated that low level of CFTR performed with cAMP and its downstream effectors such as PKA and AMPK to regulate mitochondrial structure and function, leading to increased autophagy rate and reduced vitality of sperm.

MicroRNA-363-3p inhibits colorectal cancer progression by targeting interferon-induced transmembrane protein 1

BACKGROUND The molecular mechanisms of colorectal cancer development and progression are far from being elucidated.AIM To investigate the role of microRNA-363-3p(miR-363-3p)in the progression of colorectal cancer.METHODS Real-time polymerase chain reaction was performed to detect miRNA expression in human colorectal cancer tissues and paired normal colorectal tissues.PITA 6 was utilized to predict the targets of miR-363-3p.Dual-luciferase reporter system was used to validate the target of miR-363-3p.Plate colony formation assay and wound-healing assay were performed to evaluate cancer cells’clonogenic survival ability and migration ability,respectively.Cell proliferation was examined by cell counting kit-8 assay.Immunohistochemical staining was used to determine the expression level of interferon-induced transmembrane protein 1(IFITM1)in colorectal cancer tissues and adjacent tissues.The TCGA and GTEx databases were used to compare the expression levels of IFITM1 mRNA in colorectal cancer tissues and normal colorectal tissues and analyze the correlation between the expression levels of IFITM1 mRNA and overall survival and disease-free survival of patients.A colorectal cancer cell line with a deficiency of IFITM1 was constructed,and the regulation effect of IFITM1 on the clonogenic growth of colorectal cancer cells was clarified.RESULTS MiR-363-3p was decreased in colorectal cancer tissues compared to normal colorectal tissues.IFITM1 was characterized as a direct target of miR-363-3p.Overexpression of miR-363-3p led to decreased clonogenic survival,proliferation,and migration of colorectal cancer cells,which could be reversed by forced IFITM1 expression.CONCLUSION MiR-363-3p can constrain clonogenic survival,proliferation,and migration of colorectal cancer cells via targeting IFITM1.

Study on the Knockout and the Soluble Prokaryotic Expression of VP5 Protein Transmembrane Region of IBDV

[Objective] The research aimed to construct the prokaryotic expression vector of VP5 protein of IBDV.The transmembrane region sequence of VP5 protein was knocked out.Moreover,the expression,separation and purification of objective protein were carried out.[Method] PCR technology was used to respectively amplify the extracellular and intracellular fragments of VP5 gene of IBDV.Then,the two fragments were simultaneously linked to pET-28b（＋）,and it was the vector-intracellular fragment-extracellular fragment-vector.The recombinant expression plasmid pET-VP5-FC and the improved pET-VP5-SC of VP5 whose transmembrane region gene fragment was knocked out were constructed.Then,the expression plasmid was transformed into BL21（DE3）.After IPTG induction,the recombinant protein was purified by Ni affinity chromatography and the gel filtration chromatography.[Result] The soluble expressed VP5 of IBDV was obtained.[Conclusion] The research laid the foundation for further studying the structure and function of VP5 protein.

Effect of Quercetin on the Proliferation and Mitochondrial Transmembrane Potential of CBRH-7919 Cells

[Objective] To investigate the effect of quercetin on the proliferation and mitochondrial transmembrane potential of CBRH-7919 cells. [Method] The CBRH-7919 cells of hepatocarcinoma were cultured in vitro. After treated with different concentrations of quercetin, the OD405 nm of CBRH-7919 cells was detected by using the acid phosphatase assy （APA）; morphologic changes of the cells were observed under inverted microscope; the mitochondrial transmembrane potential （△ψm） intensity changes of CBRH-7919 cells were analyzed by flow cytometry after stained with Rhodamine 123. [Result] Quercetin inhibited the proliferation of CBRH-7919 cells significantly, and the growth inhibitory effect presented time- and dose-dependent relationship. Typical decrease of cell density was observed by optical microscopy on the quercetin-treated cells. With the effect of 10 μg/ml quercetin on CBRH-7919 cells for 12, 24 and 48 h, the percentage of Rhodamine 123 stained hypofluorescence cells increased, while the mitochondrial transmembrane potential（△ψm） intensity of CBRH-7919 cells decreased. [Conclusion] Quercetin could inhibit the proliferation of CBRH-7919 cells in vitro, causing the decrease in mitochondrial transmembrane potential.

Prediction of transmembrane helical segments in transmembrane proteins based on wavelet transform

Tmnsmembrane（TM） protein plays an important role in the life activity of the cells, and the prediction of transmembrane helical segments （TMHs） is an important subject in the bioinformatics research. Thus far, several prediction methods have been reported, but there are some deficiencies in prediction accuracy and adaptability in these methods. In this paper, a method based on discrete wavelet transform （DWT） was developed to predict the TMHs. Two sets of test data sets containing total 60 protein sequences were utilized to access the effect of the method. Compared with the prediction results of TMHMM2.0 and MEMSAT, the obtained results indicate that the presented method has high prediction accuracy.

Mutational Analysis of Region-cytotoxicity Relationship in Human Transmembrane Tumor Necrosis Factor-alpha

Objective To determine the region of human transmembrane tumor necrosis factor-alpha (TM-TNFa) , essential for cytotoxic activity a-gainst human breast cancer cell line MCF-7.Methods Single amino-acid-substituted TM-TNFa mutant proteins (muteins) were produced by in vitro transcription linked translation techniques. The cDNA of TM-TNFa was site-directed mutagenized by recombinant PCR.Results 13 single ammo-acid substituted TM-TNFa muteins were generated and assayed for cytotoxic activity. The cytotoxic activities of TM-TNFa muteins, eg, TM-TNFa -71/Lys, -28/Phe and 117/Leu were significantly decreased (P < 0.01) compared to that of parent TM-TNFa, 143/Tyr decreased 4-folds, and -17/Thr, -39/Ser, 119/His, 35/Gly, 95/Cys and 147/Phe decreased 1.5-2.5-folds, respectively. However, the cytotoxic activities of TM-TNFa-8/Arg, 31/Gly and 87/Phe showed no significant change. Conclusion These results indicate that the regions associated with cytotoxic-activity of TM-TNFa are different with that of secretory TNF-alpha (S-TNFa) . The inner cell region and transmembrane region of TM-TNFa are related to the cytotoxic activity of TM-TNFa.

The transmembrane domain of TACE regulates protein ectodomain shedding

Numerous membrane proteins are cleaved by tumor necrosis factor-α converting enzyme （TACE）, which causes the release of their ectodomains. An ADAM （a disintegrin and metalloprotease domain） family member, TACE contains several noncatalytic domains whose roles in ectodomain shedding have yet to be fully resolved. Here, we have explored the function of the transmembrane domain （TM） of TACE by coupling molecular engineering and functional analysis. A TM-free TACE construct that is anchored to the plasma membrane by a glycosylphosphatidylinositol （GPI）-binding polypeptide failed to restore shedding of transforming growth factor-or （TGF-α）, tumor necrosis factor-α （TNF-α） and L-selectin in cells lacking endogenous TACE activity. Substitution of the TACE TM with that of the prolactin receptor or platelet-derived growth factor receptor （PDGFR） also resulted in severe loss of TGF-α shedding, but had no effects on the cleavage of TNF-α and L-selectin. Replacement of the TM in TGF-α with that of L-selectin enabled TGF-α shedding by the TACE mutants carrying the TM of prolactin receptor and PDGFR. Taken together, our observations suggest that anchorage of TACE to the lipid bilayer through a TM is required for efficient cleavage of a broad spectrum of substrates, and that the amino-acid sequence of TACE TM may play a role in regulatory specificity among TACE substrates.

Changes of plasma membrane ATPase activity, membrane potential and transmembrane proton gradient in Kandelia candel and Avicennia marina seedlings with various salinities

The salt-secreting mangrove, Avicennia marina, and non-salt-secreting mangrove, Kandelia candel were cultivated in sand with various salinities(0‰, 10‰, 20‰, 30‰, 40‰) for 60 d. Plasma membrane vesicles of high-purity in leaves and roots of A.marina and K. candel seedlings were obtained by two-phase partitioning. The function of the plasma membranes, the activity of ATPase, membrane potential and transmembrane proton gradient, at various salinities were investigated. The results showed that within a certain range of salinity(A. marina and roots of K. candel: 0—30‰; leaves of K.candel: 0—20‰), the activity of ATPase increased with increasing salinity, while high salinity(above 30‰ or 20‰) inhibited ATPase activity. In comparison with A. marina, K. candel appeared to be more sensitive to salinity. The dynamics of membrane potential and transmembrane proton gradient in leaves and roots of A. marina and K. candel seedlings were similar to that of ATPase. When treated directly by NaCl all the indexes were inhibited markedly: there was a little increase within 0—10‰(K. candel) or 0—20‰(A. marina) followed by sharp declining. It indicated that the structure and function of plasma membrane was damaged severely.

Tetramethylpyrazine stimulates cystic fibrosis transmembrane conductance regulator-mediated anion secretion in distal colon of rodents

AIM： To investigate the effect of tetramethylpyrazine （TMP）, an active compound from Ligustium Wollichii Franchat, on electrolyte transport across the distal colon of rodents and the mechanism involved.METHODS： The short-circuit current （Isc） technique in conjunction with pharmacological agents and specific inhibitors were used in analyzing the electrolyte transport across the distal colon of rodents. The underlying cellular signaling mechanism was investigated by radioimmunoassay analysis （RIA） and a special mouse model of cystic fibrosis.RESULTS： IMP stimulated a conoentration-dependent rise in ISCl, which was dependent on both Cl^- and HCO3^-, and inhibited by apical application of diphenylamine-2,2＇-dicarboxylic acid （DPC） and glibenclamide, but resistant to 4,4＇-diisothiocyanatostilbene-2,2＇-disulfonic acid disodium salt hydrate （DIDS）. Removal of Na^＋ from basolateral solution almost completely abolished the Isc response to TMP, but it was insensitive to apical Na^＋ replacement or apical Na^＋ channel blocker, amiloride. Pretreatment of colonic mucosa with BAPTA-AM, a membrane-permeable selective Ca2＋ chelator, did not significantly alter the TMP-induced Iso No additive effect of forskolin and 3-isobutyl-l-methylxanthine （[BMX） was observed on the TMP-induced Isc, but it was significantly reduced by a protein kinase A inhibitor, H89.RIA results showed that TMP （1 mmol/L） elicited a significant increase in cellular cAMP production, which was similar to that elicited by the adenylate cyclase activator, forskolin （10μmol/L）. The TMP-elicited Isc as well as forskolin- or IBMX-induced Isc were abolished in mice with homozygous mutation of the cystic fibrosis transmembrane conductance regulator （CFTR） presenting defective CFTR functions and secretions.CONCLUSION： TMP may stimulate cAMP-dependent and CFTR-mediated Cl^- and HCO3^- secretion. This may have implications in the future development of alternative treatment for constipation.

Cystic fibrosis transmembrane conductance regulator chloride channel blockers:Pharmacological,biophysical and physiological relevance

Dysfunction of the cystic fibrosis transmembrane con-ductance regulator(CFTR) chloride channel causes cys-tic fibrosis, while inappropriate activity of this channeloccurs in secretory diarrhea and polycystic kidney dis-ease. Drugs that interact directly with CFTR are there-fore of interest in the treatment of a number of diseasestates. This review focuses on one class of small mol-ecules that interacts directly with CFTR, namely inhibi-tors that act by directly blocking chloride movementthrough the open channel pore. In theory such com-pounds could be of use in the treatment of diarrheaand polycystic kidney disease, however in practice allknown substances acting by this mechanism to inhibitCFTR function lack either the potency or specificity forin vivo use. Nevertheless, this theoretical pharmaco-logical usefulness set the scene for the developmentof more potent, specific CFTR inhibitors. Biophysically,open channel blockers have proven most useful as ex-perimental probes of the structure and function of theCFTR chloride channel pore. Most importantly, the useof these blockers has been fundamental in developing afunctional model of the pore that includes a wide innervestibule that uses positively charged amino acid sidechains to attract both permeant and blocking anionsfrom the cell cytoplasm. CFTR channels are also subjectto this kind of blocking action by endogenous anionspresent in the cell cytoplasm, and recently this blocking effect has been suggested to play a role in the physio-logical control of CFTR channel function, in particular as a novel mechanism linking CFTR function dynamically to the composition of epithelial cell secretions. It has also been suggested that future drugs could target this same pathway as a way of pharmacologically increasing CFTR activity in cystic fibrosis. Studying open channel blockers and their mechanisms of action has resulted in significant advances in our understanding of CFTR as a pharmacological target in disease states, of CFTR chan-nel structure and function, and of how CFTR activity is controlled by its local environment.

Emerging role of cystic fibrosis transmembrane conductance regulator- an epithelial chloride channel in gastrointestinal cancers

Cystic fibrosis transmembrane conductance regulator(CFTR), a glycoprotein with 1480 amino acids, has been well established as a chloride channel mainly expressed in the epithelial cells of various tissues and organs such as lungs, sweat glands, gastrointestinal system, and reproductive organs. Although defective CFTR leads to cystic fibrosis, a common genetic disorder in the Caucasian population, there is accumulating evidence that suggests a novel role of CFTR in various cancers, especially in gastroenterological cancers, such as pancreatic cancer and colon cancer. In this review, we summarize the emerging findings that link CFTR with various cancers, with focus on the association between CFTR defects and gastrointestinal cancers as well as the underlying mechanisms. Further study of CFTR in cancer biology may help pave a new way for the diagnosis and treatment of gastrointestinal cancers.

Mem Brain: An Easy-to-Use Online Webserver for Transmembrane Protein Structure Prediction

Membrane proteins are an important kind of proteins embedded in the membranes of cells and play crucial roles in living organisms, such as ion channels,transporters, receptors. Because it is difficult to determinate the membrane protein's structure by wet-lab experiments,accurate and fast amino acid sequence-based computational methods are highly desired. In this paper, we report an online prediction tool called Mem Brain, whose input is the amino acid sequence. Mem Brain consists of specialized modules for predicting transmembrane helices, residue–residue contacts and relative accessible surface area of a-helical membrane proteins. Mem Brain achieves aprediction accuracy of 97.9% of ATMH, 87.1% of AP,3.2 ± 3.0 of N-score, 3.1 ± 2.8 of C-score. Mem BrainContact obtains 62%/64.1% prediction accuracy on training and independent dataset on top L/5 contact prediction,respectively. And Mem Brain-Rasa achieves Pearson correlation coefficient of 0.733 and its mean absolute error of13.593. These prediction results provide valuable hints for revealing the structure and function of membrane proteins.Mem Brain web server is free for academic use and available at www.csbio.sjtu.edu.cn/bioinf/Mem Brain/.

La^(3+) Transmembrane Research in Guinea Pig Ventricular Cells by Fura-2 Fluorescence

Binding of La3+ to Fura-2 can change 340/380 nm fluorescence intensity ratio. Whether La3+ cross ventricular cell membrane was detected by this fluorescent probe technique. Fura-2 loaded isolated guinea pig ventricular cells were exposed to 0.01-0.1 mM extracellular Lanthanum ion concentration, 340nm/380 nm fluorescence ratio was not changed. Using calcium channel agonist BAY K8644, KCL (35mM) depolarization to open the voltage-dependent calcium channel (VDCC); Adrenoceptor agonist to excite adrenoceptor, 340/380 ratio was not changed, suggesting that La3+can not enter guinea pig ventricular cells in this case.

Cystic fibrosis transmembrane conductance regulator prevents ischemia/reperfusion induced intestinal apoptosis via inhibiting PI3K/AKT/NF-κB pathway

BACKGROUND Intestinal ischemia/reperfusion(I/R)injury is a fatal syndrome that occurs under many clinical scenarios.The apoptosis of intestinal cells caused by ischemia can cause cell damage and provoke systemic dysfunction during reperfusion.However,the mechanism of I/R-induced apoptosis remains unclear.Cystic fibrosis transmembrane conductance regulator(CFTR)is a cAMP-activated chloride channel.Few researchers have paid attention to its role in intestinal I/R injury,or the relationship between CFTR and intestinal apoptosis induced by hypoxia/reoxygenation(H/R).AIM To investigate the effects of CFTR on I/R-induced intestinal apoptosis and its underlying molecular mechanisms.METHODS An intestinal I/R injury model was established in mice with superior mesenteric artery occlusion, and Caco2 cells were subjected to H/R for the simulation of I/R in vivo.RESULTSThe results suggested that CFTR overexpression significantly increased the Caco2 cell viability anddecreased cell apoptosis induced by the H/R. Interestingly, we found that the translocation of p65,an NF-κB member, from the cytoplasm to the nucleus after H/R treatment can be reversed by theoverexpression of CFTR, the NF-κB P65 would return from the nucleus to the cytoplasm asdetermined by immunostaining. We also discovered that CFTR inhibited cell apoptosis in theH/R-treated cells, and this effect was significantly curbed by the NF-κB activator BA, AKTinhibitor GSK690693 and the PI3K inhibitor LY294002. Moreover, we demonstrated that CFTRoverexpression could reverse the decreased PI3K/AKT expression induced by the I/R treatment invivo or H/R treatment in vitro.CONCLUSIONThe results of the present study indicate that the overexpression of CFTR protects Caco2 cells fromH/R-induced apoptosis;furthermore, it also inhibits H/R-induced apoptosis through thePI3K/AKT/NF-κB signaling pathway in H/R-treated Caco2 cells and intestinal tissues.

Effects of La^(3+)on H^+ Transmembrane Gradient and Membrane Potential in Rice Seedling Roots

The effects of LaCl 3 on membrane potential and transmembrane proton gradient for rice ( Oryza sativa ) seedling roots were studied. Highly purified plasma membrane was isolated by aqueous two phase partitioning method. Both the gradient of transmembrane proton and membrane potential were stimulated by certain low concentration of LaCl 3 and depressed by high concentration of LaCl 3. The optimal concentration of La 3+ is around 40～60 μmol·L -1 for transmembrane proton gradient and membrane potential. It shows that La 3+ can influence the generations and maintenances of membrane potential and transmembrane proton gradient in rice seedling roots.