Somatostatin receptor 1 (SSTR1) is a crucial therapeutic target for various neuroendocrine and oncological disorders. Current SSTR1-targeted treatments, including the first-generation somatostatin analog lanreotide (Lan) and the second-generation analog pasireotide (Pas), show promise but encounter challenges related to selectivity and efficacy. This study presents high-resolution cryo-electron microscopy structures of SSTR1 complexed with Lan or Pas, revealing the distinct mechanisms of ligand-binding and activation. These structures illustrate unique conformational changes in the SSTR1 orthosteric pocket induced by each ligand, which are critical for receptor activation and ligand selectivity. Combined with the biochemical assays and molecular dynamics simulations, our results provide a comparative analysis of binding characteristics within the SSTR family, highlighting subtle differences in SSTR1 activation by Lan and Pas. These insights pave the way for designing next-generation therapies with enhanced efficacy and reduced side effects through improved receptor subtype selectivity.

Parkinson's disease (PD) is the most common neurodegenerative movement disease. It is featured by abnormal alpha-synuclein (α-syn) aggregation in dopaminergic neurons in the substantia nigra. Macroautophagy (autophagy) is an evolutionarily conserved cellular process for degradation of cellular contents, including protein aggregates, to maintain cellular homeostasis. Corynoxine B (Cory B), a natural alkaloid isolated from Uncaria rhynchophylla (Miq.) Jacks., has been reported to promote the clearance of α-syn in cell models by inducing autophagy. However, the molecular mechanism by which Cory B induces autophagy is not known, and the α-syn-lowering activity of Cory B has not been verified in animal models. Here, we report that Cory B enhanced the activity of Beclin 1/VPS34 complex and increased autophagy by promoting the interaction between Beclin 1 and HMGB1/2. Depletion of HMGB1/2 impaired Cory B-induced autophagy. We showed for the first time that, similar to HMGB1, HMGB2 is also required for autophagy and depletion of HMGB2 decreased autophagy levels and phosphatidylinositol 3-kinase III activity both under basal and stimulated conditions. By applying cellular thermal shift assay, surface plasmon resonance, and molecular docking, we confirmed that Cory B directly binds to HMGB1/2 near the C106 site. Furthermore, in vivo studies with a wild-type α-syn transgenic drosophila model of PD and an A53T α-syn transgenic mouse model of PD, Cory B enhanced autophagy, promoted α-syn clearance and improved behavioral abnormalities. Taken together, the results of this study reveal that Cory B enhances phosphatidylinositol 3-kinase III activity/autophagy by binding to HMGB1/2 and that this enhancement is neuroprotective against PD.

Objective To investigate the impacts of midazolam on the proliferation,migration and invasion of breast cancer MDA-MD-231 cells and its regulation on cyclic adenosine monophosphate(cAMP)/protein kinase A(PKA)/cAMP response element binding protein(CREB)signaling pathway.Methods MDA-MD-231 cells were cultured in vitro and grouped into control group,midazolam L group,midazolam M group,midazolam H group,and midazolam H+Sp-cAMPS group.Midazolam L group,midazolam M group,midazolam H group were treated with 5μmol/L,10μmol/L,and 20μmol/L of midazolam,respectively,midazolam H+Sp-cAMPS group was added with 20μmol/L of midazolam+10μmol/L of Sp-cAMPS 3-(4,5)-dimethylthiahiazo(-z-y1)-3,5-di-phenytetrazoliumromide(MTT)assay was applied to detect cell proliferation;The migration ability was detected by cell scratch test;Transwell test was applied to determine the invasion ability of cells;Cell apoptosis was detected by flow cytometry;The expression level of cAMP was detected by enzyme-linked immunosorbent assay(ELISA);Western blot was applied to verify the expression of phosphorylated(p-)PKA/PKA,p-CREB/CREB protein.Results Compared with control group,the cells in midazolam L group,midazolam M group,midazolam H group showed apoptosis,the apoptosis rate was obviously increased,the cell proliferation,migration and invasion abilities and the expression levels of cAMP,p-PKA/PKA,p-CREB/CREB proteins were obviously decreased(P<0.05);Compared with midazolam H group,midazolam H+Sp-cAMPS group had good cell growth,obviously reduced apoptosis rate,and obviously increased cell proliferation,migration and invasion abilities,and the expression levels of cAMP,p-PKA/PKA,p-CREB/CREB proteins(P<0.05).Conclusion Midazolam may inhibit the proliferation,migration and invasion of breast cancer cells by inhibiting the activation of cAMP/PKA/CREB signaling pathway.

Objective To observe the effects of interfering Twist expression on glycolysis in pancreatic cancer PANC1 cells and explore the potential mechanism.Methods Twist targeting siRNA (siTWIST) was designed and synthesized,and pancreatic cancer PANC1 cells were transfected with siTWIST using liposome,with nonspecific siRNA (siNC) transfected cells as negative control group and untransfected cells as blank control group.RT-PCR and Western blot were used to detect the expression levels of Twist mRNA and protein,and Akt and p-Akt protein expression in different groups;cell proliferation was detected by MTT;and glycolysis key enzyme (pyruvate kinase and hexokinase) activity and the content of lactic acid in the supernatant of culture fluid were detected.Results Twist mRNA level in control group,siRNA group and siTwist group expression was 1.00 ± 0.09,1.01 ± 0.08 and 0.36 ± 0.02;Twist protein level was 0.41 ± 0.05,0.42 ± 0.04 and 0.12 ± 0.06;the mRNA and protein expression in siTWIST group was obviously lower than those in control group and the difference was statistically significant (P ＜ 0.05).The cell survival rate was (100.02± 9.36)％,(100.01 ± 10.25)％ and (59.32± 7.26)％,which in siTWIST group was obviously lower than that in control group;pyruvate kinase activity was (0.73 ± 0.05)U/mg,(0.72 ± 0.08) U/mg and (0.43 ± 0.05) U/mg;the activities of hexokinase were (4.98 ± 0.48) U/mg,(4.96 ± 0.52) U/mg and (2.54 ± 0.21) U/mg;the content of lactic acid was (20.36 ± 2.61) mmol/L,(20.64 ± 3.05) mmol/L and (9.48 ± 1.09) mmol/L;the ratio of p-Akt/Akt was 0.65 ± 0.04,0.63 ± 0.07,and 0.25 ± 0.04,which in siTWIST group was obviously lower than that in control group.Conclusions Interference with Twist expression could inhibit the proliferation and glycolysis pathway in pancreatic cancer cells,and the mechanism may be related to the Akt signaling pathway.

OBJECTIVETo explore the NEK-6 expression in gastric cancer tissue and its relationship with clinicopathological features.

METHODSFluorescent quantification PCR and Western blotting were used to examine the NEK-6 expression in 36 samples of fresh gastric cancer tissues and para-cancer gastric mucosal tissues, human gastric cancer cell lines(BGC-823, MKN-28, SGC-7901, MGC-803, HGC-27, AGS), and human normal gastric epithelial cell line (GES-1). Gastric cancer cell lines with the highest expression level were selected to perform the invasion and migration tests, and the effect of down-regulated NEK-6 expression by siRNA transfection on above invasion and migration tests were observed. Meanwhile NEK-6 expression in 94 paraffin samples of gastric cancer tissues was examined by immunohistochemistry and its positivity was compared among different clinicopathologic features.

RESULTSFluorescent quantification PCR revealed gastric cancer tissues had significantly higher NEK-6 expression than para-cancer tissues(0.002 80±0.001 36 vs. 0.001 91±0.001 48, P<0.05), NEK-6 expression was up-regulated in 31 gastric cancer tissues (86.1%), and human gastric cancer cell lines had significantly higher NEK-6 expression than GES-1 cells, among whom BGC-823 and AGS cell lines were the highest. Invasion and migration tests showed that as compared to negative siRNA control group, ability of invasion and migration in BGC-823 and AGS cells after siRNA transfection was obviously decreased. In 94 paraffin samples, positive expression rate of NEK-6 was 60.6%(57/94), and NEK-6 expression was significantly associated with gastric cancer distant metastasis, lymph nodes metastasis and TNM staging(all P<0.05).

CONCLUSIONSNEK-6 expression is up-regulated in gastric cancer tissues, which is significantly associated with distant metastasis, lymph nodes metastasis and TNM staging. Down-regulation of NEK-6 expression can inhibit the ability of invasion and migration in gastric cancer cells.

OBJECTIVETo explore the changes of anticancer efficiency of 5'-deoxy-5-fluorouridine (5'-DFUR) and 5-fluorouracil (5-Fu) in colorectal cancer cell line HT29 and LS174T cells after transfection of thymidine phosphorylase (TP) cDNA with a lentiviral vector.

METHODSTP cDNA was transfected into human colorectal cancer cell lines HT29 and LS174T with the lentiviral vector pLenti6.3-MCS-IRES2-EGFP, and the transfection efficiency of the two cell lines passed 5 generations was analyzed by flow cytometry. The expression of TP protein and the relative quantitative expression of TP mRNA in these 2 cell lines were detected by Western blot and RT-PCR, respectively. The 50% inhibitory concentration (IC50) of 5'-DFUR and 5-Fu in both HT29 and LS174T parent cells and TP-transfected cells were assessed by MTS assay. Finally, the concentration of converted 5-Fu was detected by high performance liquid chromatography (HPLC) either in the medium containing a series of concentrations of 5'-DFUR, in which HT29/HT29-TP or LS174T/LS174T-TP cells were cultured, or in the cell culture lysates.

RESULTSThe HT29 and LS174T cells transfected with human TP cDNA were monitored for 5 generations, and their transfection efficiency was about 95.0%. Immunohistochemical staining showed that both the parent cells and TP-transfected HT29 and LS174T cells were TP-positive, while vector-transfected cells were TP-negative. Western blotting showed that the TP protein expression in HT29-TP and LS174T-TP cells were significantly increased compared with that in their parents cells. The relative quantity (RQ) values of TP mRNA in HT29-TP and LS174T-TP cells were 8.45 ± 0.15 and 2 615.02 ± 253.97, respectively, which were significantly higher than that in their parents cells (P < 0.01). The IC50 values of 5'-DFUR on HT29-TP cells and its parents cell were (14.33 ± 0.74) µmol/L and (707.66 ± 5.66) µmol/L, respectively (P < 0.05), while (0.59 ± 0.11) µmol/L in LS174T-TP cells and (239.20 ± 21.83) µmol/L in its parent cells, respectively (P < 0.05). The IC50 values of 5-Fu of HT29-TP cells and its parents cells were (5.42 ± 0.75) µmol/L and (14.19 ± 0.97) µmol/L, respectively (P < 0.05), while (4.41 ± 0.96)µmol/L in LS174T-TP cells and (16.42 ± 2.12)µmol/L in its parents cells, respectively (P < 0.05). The HPLC results showed that the 5-Fu concentration detected from media contained a series of concentrations of 5'-DFUR for culturing HT29-TP and LS174T-TP cells were 12.2 to 28.7-folds and 13.1 to 23.6-folds, respectively, higher than that in their parents cells, (P < 0.01 for all). Otherwise, just a little of 5-Fu was detected in the two TP-transfected cells lysate, about 0.9% to 4.2% of 5-Fu detected in the media of the same cultured cells, whereas no 5-Fu was detected in the two parent cell lysates.

CONCLUSIONSTransfection of TP cDNA into colorectal cancer cell lines HT29 and LS174T with lentiviral vector can improve the expression of both TP mRNA and TP protein levels in passaged cells, enhance the conversion of 5-Fu from 5'-DFUR in the medium, and result in an enhanced anticancer effect on these two cell lines.

Antineoplastic Agents ; pharmacology ; Cell Line ; Cell Line, Tumor ; Colorectal Neoplasms ; genetics ; metabolism ; DNA, Complementary ; Floxuridine ; pharmacology ; Fluorouracil ; Genetic Vectors ; HT29 Cells ; Humans ; RNA, Messenger ; Thymidine Phosphorylase ; genetics ; metabolism ; Transfection

Objective To explore the NEK-6 expression in gastric cancer tissue and its relationship with clinicopathological features. Methods Fluorescent quantification PCR and Western blotting were used to examine the NEK-6 expression in 36 samples of fresh gastric cancer tissues and para-cancer gastric mucosal tissues, human gastric cancer cell lines ﹙BGC-823, MKN-28, SGC-7901, MGC-803, HGC-27, AGS), and human normal gastric epithelial cell line ﹙GES-1). Gastric cancer cell lines with the highest expression level were selected to perform the invasion and migration tests, and the effect of down-regulated NEK-6 expression by siRNA transfection on above invasion and migration tests were observed. Meanwhile NEK-6 expression in 94 paraffin samples of gastric cancer tissues was examined by immunohistochemistry and its positivity was compared among different clinicopathologic features. Results Fluorescent quantification PCR revealed gastric cancer tissues had significantly higher NEK-6 expression than para-cancer tissues ﹙0.002 80 ±0.001 36 vs. 0.001 91 ±0.001 48, P<0.05), NEK-6 expression was up-regulated in 31 gastric cancer tissues ﹙86.1%), and human gastric cancer cell lines had significantly higher NEK-6 expression than GES-1 cells, among whom BGC-823 and AGS cell lines were the highest. Invasion and migration tests showed that as compared to negative siRNA control group, ability of invasion and migration in BGC-823 and AGS cells after siRNA transfection was obviously decreased. In 94 paraffin samples, positive expression rate of NEK-6 was 60.6%﹙57/94),and NEK-6 expression was significantly associated with gastric cancer distant metastasis, lymph nodes metastasis and TNM staging ﹙all P<0.05). Conclusions NEK-6 expression is up-regulated in gastric cancer tissues, which is significantly associated with distant metastasis, lymph nodes metastasis and TNM staging. Down-regulation of NEK-6 expression can inhibit the ability of invasion and migration in gastric cancer cells.

Objective To explore the NEK-6 expression in gastric cancer tissue and its relationship with clinicopathological features. Methods Fluorescent quantification PCR and Western blotting were used to examine the NEK-6 expression in 36 samples of fresh gastric cancer tissues and para-cancer gastric mucosal tissues, human gastric cancer cell lines ﹙BGC-823, MKN-28, SGC-7901, MGC-803, HGC-27, AGS), and human normal gastric epithelial cell line ﹙GES-1). Gastric cancer cell lines with the highest expression level were selected to perform the invasion and migration tests, and the effect of down-regulated NEK-6 expression by siRNA transfection on above invasion and migration tests were observed. Meanwhile NEK-6 expression in 94 paraffin samples of gastric cancer tissues was examined by immunohistochemistry and its positivity was compared among different clinicopathologic features. Results Fluorescent quantification PCR revealed gastric cancer tissues had significantly higher NEK-6 expression than para-cancer tissues ﹙0.002 80 ±0.001 36 vs. 0.001 91 ±0.001 48, P<0.05), NEK-6 expression was up-regulated in 31 gastric cancer tissues ﹙86.1%), and human gastric cancer cell lines had significantly higher NEK-6 expression than GES-1 cells, among whom BGC-823 and AGS cell lines were the highest. Invasion and migration tests showed that as compared to negative siRNA control group, ability of invasion and migration in BGC-823 and AGS cells after siRNA transfection was obviously decreased. In 94 paraffin samples, positive expression rate of NEK-6 was 60.6%﹙57/94),and NEK-6 expression was significantly associated with gastric cancer distant metastasis, lymph nodes metastasis and TNM staging ﹙all P<0.05). Conclusions NEK-6 expression is up-regulated in gastric cancer tissues, which is significantly associated with distant metastasis, lymph nodes metastasis and TNM staging. Down-regulation of NEK-6 expression can inhibit the ability of invasion and migration in gastric cancer cells.

Objective To explore the factors which could lead to a preoperative diagnosis and to guide the management of cholecystoduodenal fistula (CDF).Method The experience on the diagnosis and treatment of 22 patients with CDF were retrospectively studied.These patients came from 1242 patients who received biliary tract operation in our hospital from 2001 to 2012.Results 64％ (14 of 22 patients) had 3 out of 5 of the following symptoms/signs:(1) symptoms of recurrent chills and fever,with no or only mild jaundice; (2) significant atrophy or disappearance of gallbladder on computed tomography (CT) ; (3) CT revealed complex anatomy in right upper abdomen with dilated loops of bowel; (4) ultrasound or CT revealed pneumobilia or pneumo-gallbladder; (5) barium study or duodenal endoscopy revealed obvious deformation in duodenal bulb or abnormal opening.There was no perioperative death.Morbidities included biliary fistula which presented on postoperative day 6 and day 7 in 2 patients,respectively.The daily volume of bile drainage was about 500 ml,and the biliary fistula healed after a month of conservative treatment.In addition,there were 6 patients who had infected wound,8 patients with right pleural effusion,and 8 patients with residual calculi.There was no intestinal fistula or biliary stricture.Conclusions Careful preoperative history taking and CT/uhrasound studies significantly improved the diagnostic rate of CDF.Individualized treatment reduced complications and improved clinical results.

Objective To investigate antimicrobial resistance among Streptococcus pneumoniae clinically isolated from 14 teaching hospitals located at different areas in China in 2005-2008 and to give logical guidance for clinical empirical therapy.Methods A total of 1 317 non-repetitive S.pneumoniae isolates in 14 teaching hospitals from 2005-2008 were collected and sent to the central lab for reidentification and susceptibility testing, including 271 isolates collected in 2005, 391 isolates collected in 2006, 363 isolates collected in 2007 and 292 isolates collected in 2008. Most of the isolates were from community-acquired respiratory tract infections, which were isolated from outpatient or emergency department patients with respiratory tract infections or those patients with respiratory tract infections within ≤48 hours hospitalization.The districts where the organisms were isolated include North China, Northeast China, South China, Central and Northwest China and East China.The patients included adults, teenagers and children.The minimum inhibitory concentrations (MICs) or inhibitory zone diameter of 17 antimicrobial agents were determined by Etest method, agar dilution method or disk diffusion method.WHONET5.5 software was used to analyze susceptibility rate, intermediate rate, resistance rate, MIC50 and MIC90.Results Linezolid (100%) and fluoroquinolones (95.2%-99.7%) showed excellent activities against S.pneumoniae.Among β-lactams, amoxicillin-clavulanic acid remained high activities (73.8%-92.1%),followed by penicillin, ceftriaxone and cefepime with year-over-year decrease in activities.The activities of three second-generation cephalosporins were low (36.3%-38.4% in 2008).The activities of erythromycin, azithromycin, clindamycin, trimethoprim/sulfamethoxazole and tetracycline against S.pneumoniae were poor and decreased year over year.The incidence of penicillin non-susceptible S.pneumoniae (PNSP) was increasing especially for PISP (from 4.4% in 2005 to 20.2% in 2008).The incidence of PNSP in North China was low (6.0%), while this value were high in central China and East China (30.1% and 38.7%, separately).The incidence of PNSP in adults (15.7%) was obviously lower than that in children(≤5 years:33.0%) and teenagers (6-17 years:38.2%).Conclusions linezolid and fluoroquinolones showed excellent in vitro activity against S.pneumoniae, followed by penicillin and cephalosporins with year-over-year decrease of activity. Clinicians should pay more attention when using those antimicrobial agents with poor activity against S.pneumoniae, which include macrolides, clindamycin, trimethoprim/sulfamethoxazole and tetracycline.