Tertiary Lymphoid Structure Raises Survival and Immunotherapy in HPV- HNSCC.

Immune checkpoint blockade (ICB) targeting PD-1/PD-L1 has been used for the treatment of head and neck squamous cell carcinoma (HNSCC). However, the overall response rate to ICB therapy for HNSCC remains less than 20%. It has recently been reported that the appearance of tertiary lymphoid structures (TLSs) in tumor tissue is correlated with better prognosis and response to ICB treatment. Here, we demonstrated an immune classification for the tumor microenvironment (TME) of HNSCC by analyzing The Cancer Genome Atlas (TCGA)-HNSCC data set and found that immunotype D with TLS enrichment had a better prognosis and response to ICB treatment. Furthermore, we observed that TLSs were present in a part of tumor samples of human papillomavirus (HPV) infection negative HNSCC (HPV- HNSCC) and were associated with the densities of dendritic cell (DC)-LAMP+ DCs, CD4+ T cells, CD8+ T cells, and progenitor T cells in TME. We established an HPV- HNSCC mouse model with TLS-enriched TME by overexpressing LIGHT in a mouse HNSCC cell line. We found that the induction of TLS formation enhanced the response to PD-1 blockade treatment in the HPV- HNSCC mouse model, accompanied by increases in DCs and progenitor exhausted CD8+ T cells in the TME. Elimination of CD20+ B cells attenuated the therapeutic effect of PD-1 pathway blockade in TLS+ HPV- HNSCC mouse models. These results indicate that TLSs contribute to the favorable prognosis and antitumor immunity of HPV- HNSCC. Inducing TLS formation in HPV- HNSCC tumors is a potential therapeutic method for improving the ICB response rate in patients with HPV- HNSCC.

[Prognostic values of stromal tumor-infiltrating lymphocytes and lymphocyte-activation gene-3 in advanced gastric adenocarcinoma].

Objective: To analyze density of stromal tumor-infiltrating lymphocytes (sTIL) and expression of lymphocyte-activation gene-3 (LAG-3) protein in advanced gastric adenocarcinomas, and to investigate the correlation of sTIL and LAG-3 with the prognosis in patients with advanced gastric adenocarcinoma. Methods: The clinicopathological characteristics and follow-up data of 260 patients with advanced gastric adenocarcinoma were collected at Fujian Cancer Hospital, from January 2011 to December 2014. The percentage of sTILs was reported semi-quantitatively using histological section evaluation, the LAG-3 protein was detected using immunohistochemistry, and the expression was correlated with the clinicopathological features and patient outcomes. Results: Among the 260 cases, high density of sTIL was detected in 173 cases (66.5%) while LAG-3 high expression was observed in 160 cases (61.5%). These cases were divided into four groups. Group Ⅰ: 48 cases (18.5%) were sTIL low/LAG-3 low; group Ⅱ: 52 cases (20.0%) were sTIL high/LAG-3 low; group Ⅲ: 39 cases (15.0%) were sTIL low/LAG-3 high; group Ⅳ: 121 cases (46.5%) were sTIL high/LAG-3 high. Kaplan-Meier survival analyses showed that patient prognoses were related to age, tumor size, tumor location, Lauren classification, perineural invasion, vascular invasion, TNM staging, postoperative adjuvant chemotherapy and molecular classification (P<0.05). Meanwhile, higher densities of sTIL and higher expression of LAG-3 were associated with better prognosis. Multivariate survival analysis showed age, tumor size, Lauren classification and postoperative adjuvant chemotherapy were independent prognostic factors for patient survival. The results showed a poor prognosis in low-sTIL/low-LAG-3 patients. Conclusions: Compared with low density of sTIL and low expression of LAG-3, high density of sTIL and high expression of LAG-3 are associated with better outcomes in patients with advanced gastric adenocarcinoma, respectively. Combined detecton of sTIL and LAG-3 may be more useful in gastric cancer than using either alone. Age, tumor size, Lauren classification and postoperative adjuvant chemotherapy are independent prognostic factors for patients with advanced gastric adenocarcinoma.

Remifentanil reduces multiple organ and energy metabolism disturbances in a rat sepsis model.

The aim of this study was to observe the effects of remifentanil on organ damage and energy metabolism in lipopolysaccharide (LPS)-induced septic rats. A total of 45 clean-grade male Wistar rats (weight 270-320 g) were randomly divided into three groups: a control group, an LPS group, and an LPS with remifentanil treatment (LPS+REM) group. After 6 hours of modeling, the levels of tumor necrosis factor α (TNF-α) and interleukin-6 (IL-6) in lung and kidney tissues of rats in each group were detected by ELISA. The activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) in lung and kidney tissues were determined, and the content of lactic acid, pyruvate and epinephrine in heart and kidney tissues were detected. Reverse transcription polymerase chain reaction and the Western blot test were used to detect the expression of pyruvate dehydrogenase kinase 4 (PDK4) in the myocardial tissue. We found that remifentanil treatment inhibited the levels of IL-6, TNF-α, and MDA in the lung and kidneys 6 h after the administration of LPS and increased the level of SOD activity. Treatment with remifentanil reduced the expression of lactic acid, pyruvate, and epinephrine in the heart and kidney tissues and attenuated the expression of PDK4 messenger RNA and PDK4 protein in the myocardial tissue. We concluded that remifentanil might inhibit the release of tissue inflammatory factors, regulate the body's energy metabolism, and ultimately protect the sepsis tissue damage caused by LPS.

[Clinicopathological features of NTRK3 gene rearrangement papillary thyroid carcinoma].

Objective: To investigate the clinicopathological features and differential diagnosis of NTRK3 gene rearrangement thyroid papillary carcinoma (PTC). Methods: The PTC cases without BRAF V600E mutation were collected at Fujian Provincial Hospital South Branch from January 2015 to January 2020. The cases of NTRK3 gene rearrangement PTC were examined using immunohistochemistry and fluorescence in situ hybridization (FISH). The clinical data, histopathological characteristics, immunohistochemical features and molecular pathological changes were retrospectively analyzed. Data from the TCGA PTC dataset and the literature were also studied. Results: A total of 3 PTC cases harboring NTRK3 gene rearrangement were confirmed. All the patients were female, aged from 26,49,34 years. Histologically, two of them demonstrated a multinodular growth pattern. Only one case showed prominent follicular growth pattern; the other two tumors showed a mixture of follicular, papillary and solid growth patterns. All tumors showed a typical PTC nuclear manifestation, with some nuclear pleomorphism, vacuolated foci and oncocytic features. The characteristic formation of glomeruloid follicular foci was present in two cases which also showed psammoma bodies, and tumoral capsular or angiolymphatic invasion. The background thyroid parenchyma showed chronic lymphocytic thyroiditis. Mitotic rates were low, and no cases had any tumor necrosis. The pan-TRK and TTF1 testing was both positive in 3 cases, while S-100 and mammaglobin were both negative in them. FISH studies confirmed the NTRK3 gene rearrangement in all 3 cases. Studies on the TCGA datasets and literature revealed similar findings. Conclusions: NTRK3 gene rearrangement PTC is rare. It may be easily misdiagnosed due to the lack of histological and clinicopathological characteristics. Molecular studies such as pan-TRK immunostaining, FISH and even next-generation sequencing are needed to confirm the diagnosis. Immunohistochemistry of pan-TRK performed in the PTC cases without BRAF V600E mutation can be used as a good rapid-screening tool. With the emergence of pan-cancer tyrosine receptor kinase inhibitors, proper diagnosis of these tumors can help determine appropriate treatments and improve their outcomes.

GSDME Is Related to Prognosis and Response to Chemotherapy in Oral Cancer.

Gasdermin E (GSDME), as the major executive protein of pyroptosis, has been considered to be linked to antitumor immunity in recent years. However, the role of GSDME in oral squamous cell carcinoma (OSCC) remains to be elucidated. Here, by using a human OSCC tissue microarray, human OSCC tissue, and Tgfbr1/Pten conditional knockout mice, we found that GSDME was strongly expressed in OSCC and that GSDME expression in primary tumors was higher than that in metastatic lymph nodes. In addition, GSDME expression in OSCC was positively related to better prognosis. Moreover, GSDME-mediated pyroptosis occurred upon stimulation with chemotherapy drugs, and functional knockdown of GSDME attenuated the cisplatin-induced antitumor effect. Consistent with these results, bioinformatic analysis indicated that GSDME expression was positively correlated with the sensitivity of a number of antitumor drugs approved by the US Food and Drug Administration. Inhibition of GSDME expression by small interfering RNA in SCC7 cells significantly increased the expression of the cancer stem cell markers, CD44 and ALDH1. Furthermore, multiplexed immunohistochemistry and flow cytometry indicated that the expression of GSDME positively correlated with tumor-infiltrating CD8+ T cells, granzyme B, and M1 phenotype macrophages. Collectively, these findings demonstrated that GSDME is a potential positive prognostic factor of OSCC, and GSDME-mediated pyroptosis induced by chemotherapy plays a role in antitumor response.

[Efficacy of olaparib combined with pembrolizumab in second-line treatment for extensive-stage small cell lung cancer].

Objective: To compare the efficacy and safety of olaparib in combination with pembrolizumab with pembrolizumab alone in second-line treatment for patients with extensive stage-small cell lung cancer (ES-SCLC) whose ages ranged from 40 to 80 years. Methods: From March 2017 to October 2019, 21 patients with progressed or relapsed small cell lung cancer after standard first line treatment were enrolled in this study. The olaparib/pembrolizumab group (n=11) was treated by olaparib 300mg twice per day combined with pembrolizumab 200mg once every 3 weeks, while pembrolizumab group was treated by pembrolizumab alone. Results: The objective response rate (ORR) of olaparib/pembrolizumab group and pembrolizumab group were 45.5% and 10.0%, respectively (P=0.149), and the disease control rate (DCR) were 81.8% and 70.0% (P=0.635). The median progression-free survival (PFS) were 5.93 months and 3.53 months (P=0.036), the median overall survival (OS) were 10.43 months and 8.43 months (P=0.063). The adverse reaction incidences of all grades were 90.9% and 70.0% (P=0.311), and the incidences of grade Ⅲ-Ⅴ including myelosuppression were 36.4% and 10.0% (P=0.311), gastrointestinal reaction were 9.1% and 10.0%, (P=1.000) and other immune-related adverse events were 18.2% and 30.0% (P=1.000). Further analysis showed the metastatic number (P=0.006), platinum sensitivity (P=0.036) and LDH level (P=0.022) significantly affected the ORR of olaparib/pembrolizumab therapy. Conclusion: Our preliminary study indicates that olaparib combined with pembrolizumab is an efficient and safe second-line treatment therapy for patients with ES-SCLC.

LncRNA SNHG16 functions as an oncogene by sponging miR-200a-3p in pancreatic cancer.

Since this article has been suspected of research misconduct and the corresponding authors did not respond to our request to prove originality of data and figures, "LncRNA SNHG16 functions as an oncogene by sponging miR-200a-3p in pancreatic cancer, by J.-Q. Guo, Z.-J. Yang, S. Wang, Z.-Z. Wu, L.-L. Yin, D.-C. Wang, published in Eur Rev Med Pharmacol Sci 2020; 24 (4): 1718-1724-DOI: 10.26355/eurrev_202002_20347-PMID: 32141539" has been withdrawn. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/20347.

LncRNA SNHG16 functions as an oncogene by sponging miR-200a-3p in pancreatic cancer.

OBJECTIVE: Recently, the role of long noncoding RNAs (lncRNAs) is vital in tumor progression. Our study aims to identify the role of SNHG16 in the metastasis of pancreatic carcinoma. PATIENTS AND METHODS: Real-Time quantitative Polymerase Chain Reaction (RT-qPCR) was used to measure SNHG16 expression in 56 pancreatic carcinoma patients' tissues. Function assays, including wound healing assay, and transwell assay, were conducted to detect the effect of SNHG16 on the metastasis of pancreatic carcinoma. Besides, the luciferase assay was performed to explore the underlying mechanism. RESULTS: The expression level of SNHG16 was upregulated in pancreatic carcinoma samples compared with adjacent tissues. Moreover, cell migration and cell invasion were repressed via the knockdown of SNHG16, while cell migration and cell invasion were promoted via the overexpression of SNHG16. Moreover, the expression of miR-200a-3p was upregulated via knockdown of SNHG16 while the expression of miR-200a-3p was downregulated via the upregulation of SNHG16 in vitro. Furthermore, it was discovered that SNHG16 acted as a competing endogenous RNA via sponging miR-200a-3p in pancreatic carcinoma. CONCLUSIONS: Our study suggests that SNHG16 acts as an oncogene in pancreatic carcinoma and promotes cell metastasis via sponging miR-200a-3p, which might be a novel therapeutic strategy in pancreatic carcinoma.

Effects of rumen-protected folic acid and betaine supplementation on growth performance, nutrient digestion, rumen fermentation and blood metabolites in Angus bulls.

This study evaluated the effects of rumen-protected folic acid (RPFA) and betaine (BT) on growth performance, nutrient digestion and blood metabolites in bulls. Forty-eight Angus bulls were blocked by body weight and randomly assigned to four treatments in a 2 × 2 factorial design. BT of 0 or 0·6 g/kg DM was supplemented to diet without or with the addition of 6 mg/kg DM of folic acid from RPFA, respectively. Average daily gain increased by 25·2 and 6·29 % for addition of BT without RPFA and with RPFA, respectively. Digestibility and ruminal total volatile fatty acids of neutral-detergent fibre and acid-detergent fibre increased, feed conversion ratio and blood folate decreased with the addition of BT without RPFA, but these parameters were unchanged with BT addition in diet with RPFA. Digestibility of DM, organic matter and crude protein as well as acetate:propionate ratio increased with RPFA or BT addition. Ruminal ammonia-N decreased with RPFA addition. Activity of carboxymethyl cellulase, cellobiase, xylanase, pectinase and protease as well as population of total bacteria, protozoa, Fibrobacter succinogenes and Ruminobacter amylophilus increased with RPFA or BT addition. Laccase activity and total fungi, Ruminococcus flavefaciens and Prevotella ruminicola population increased with RPFA addition, whereas Ruminococcus albus population increased with BT addition. Blood glucose, total protein, albumin, growth hormone and insulin-like growth factor-1 increased with RPFA addition. Addition of RPFA or BT decreased blood homocysteine. The results indicated that addition of BT stimulated growth and nutrient digestion in bulls only when RPFA was not supplemented.

Resveratrol protects against oxidative damage of retinal pigment epithelium cells by modulating SOD/MDA activity and activating Bcl-2 expression.

OBJECTIVE: Age-related macular degeneration (AMD) is mainly characterized by dysfunction of retinal pigment epithelium (RPE) cells. This study aimed to investigate the protective effects of resveratrol on oxidative damaged RPE cells. MATERIALS AND METHODS: Human D407 cells were divided into normal control (NC), H2O2 treated (H2O2, treating with H2O2 at a final concentration of 200 mol/l) and resveratrol treatment groups (treating with resveratrol at a concentration of 12.5, 25, 50 and 100 mg/l). Malondialdehyde (MDA) and superoxide dismutase (SOD) activities were examined using enzyme-linked immunosorbent assay (ELISA). 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) and cell count kit-8 (CCK-8) were used to examine cell viability. Cell cycle phase distribution and apoptosis of D407 cells were evaluated using flow cytometry assay. B-cell lymphoma-2 (Bcl-2) and cleaved caspase 3 expression were detected using quantitative real-time PCR (qRT-PCR) and Western blot assay, respectively. RESULTS: Resveratrol significantly decreased inhibitive ratios of D407 cell growth compared to that of H2O2 group (p<0.05). Resveratrol significantly increased SOD activity compared to that of H2O2 group (p<0.05). Resveratrol significantly reduced MDA activity compared to that of H2O2 group (p<0.05). Resveratrol affected cell cycle phase distribution of D407 cells compared to that of H2O2 group (p<0.05). Resveratrol significantly decreased the early stage and late stage apoptosis rates compared to that of H2O2 group (p<0.05). Resveratrol significantly enhanced Bcl-2 levels and decreased cleaved caspase 3 levels compared to that of H2O2 group (p<0.05). CONCLUSIONS: Resveratrol protected against the oxidative damage of RPE cells by modulating SOD/MDA activity and activating Bcl-2 expression.

[Cyto-inactivation instantly induced by microwave ablation on thyroid nodules].

Objective: To explore the effect of microwave ablation on thyroid nodules cell activity by the reaction of key enzyme of cell activation. Methods: From November 2017 to February 2018, 104 patients with 120 thyroid nodules underwent ultrasound-guided microwave ablation at Super-minimally Invasive Medicals, Shanghai International Medical Center, aged 14-55 years, 42 males and 62 females.Twice core needle biopsy were performed before and after thermal ablation.The specimen were using hematoxylin and eosin (HE) staining and enzyme histochemical staining with include succinate dehydrogenase (SDH) and nicotinamide adeninedinucleotide phosphate diaphorase (NADPH-d), respectively, and observe under microscope. Results: Enzyme histochemical staining showed that the positive rate of SDH and NADPH-d in the marginal region and transitional region were 100% before ablation, and were 0% immediately after ablation.The positive rate of SDH and NADPH-d histochemical staining in the same area before and immediately after ablation was statistically significant (P<0.05). Shortly after microwave ablation, the tissue structure and cell morphology showed no obvious alteration in HE stained sections, but in sections with enzyme histochemical staining, the activity of SDH and NADPH-d in ablated tissue disappeared.The accuracy rate of pathologic diagnosis was 100% after ablation. Conclusions: SDH and NADPH-d enzyme activity may be better in evaluating the short-term efficacy of microwave ablation of thyroid nodules than HE staining.

[Metabolic syndrome and its influencing factors in professional automobile drivers in a company].

OBJECTIVE: To investigate the prevalence of metabolic syndrome (MS)in 259 professional automobile drivers, and to put forward targeted suggestions on protection. METHODS: In October 2014, 114 male bus drivers and 145 male taxi drivers in a transportation service company were enrolled as investigation group, and 121 non-operating male staff were enrolled as control group. Physical examination and a questionnaire survey were conducted for both groups, and the results were analyzed. RESULTS: The bus drivers and taxi drivers had significantly higher prevalence rates of MS than the nonoperating staff(17.5%/13.1% vs 3.3%, P<0.05). The results of univariate logistic analysis showed that smoking(OR=2.58, 95%CI 1.14~5.88), exercise (OR=0.21, 95% CI 0.10~0.43), meal time (OR=0.27, 95% CI 0.13~0.59), and a family history of chronic diseases (OR=2.26, 95% CI 1.13~4.50)were associated with MS, and each independent variable showed significant differences between groups (P<0.05). Multivariate logistic regression analysis showed that with age remaining the same, smoking was the risk factor for MS in professional automobile drivers (OR=5.25, 95%CI 2.00~13.80), and meal time (20~40 min)(OR= 0.20, 95%CI 0.09~0.44)and exercise (OR=0.13, 95% CI 0.06~0.30)were protective factors against MS. CONCLUSION: Professional automobile drivers have a higher prevalence rate of MS than non-operating staff, which should be taken seriously by working personnel.

[Association between efficacy and molecular subtypes in breast cancer patients receiving neoadjuvant chemotherapy].

OBJECTIVE: To investigate the association between pathological complete response (pCR), clinicopathological characteristics and clinical outcomes in breast cancer patients receiving neoadjuvant chemotherapy. METHODS: Medical records of 221 patients who underwent neoadjuvant chemotherapy for breast cancer between January 2006 and December 2008 were retrospectively reviewed. Their clinicopathological features, response to neoadjuvant chemotherapy, survivals and prognostic factors were then analyzed. RESULTS: The total pCR rate was 11.3% (25/221). The rate of pCR was 0%(0/12), 5.7%(6/106), 7.4%(2/27) and 16.9%(11/65) in the luminal A, luminal B, HER-2, and Basal-like subtypes, respectively. Statistically significant association was found between the pCR rate and the molecular substypes of breast cancer(P<0.05). The median 5-year disease free survival and the 5-year overall survival were 72 months and 79 months. The 5-year disease free survival rate and 5-year overall survival rate were 61.1% and 71.9% in all the 221 patients. The 5-year disease free survival rates of pCR and non-pCR patients were 84.0% and 58.2%, and the 5-year overall survival rates of pCR and non-pCR patients were 96.0% and 68.9%, respectively(P<0.05 for all). The multivariate survival analysis showed that clinical and pathological node stage and pCR are independent prognostic factors for the 5-year disease-free survival and 5-year total survival in patients with neoadjuvant chemotherapy (P<0.05 for both). CONCLUSIONS: pCR is more frequently observed in HER-2 and basal-like breast cancer subtypes compared with the luminal breast cancer subtype. The status of clinical and pathological node status and pCR are independent prognostic factors in patients treated with neoadjuvant chemotherapy.

A packed Cytodex microbead array for three-dimensional cell-based biosensing.

A packed Cytodex 3 microbead array was fabricated as a simple three-dimensional (3-D) cell-based biosensing format. Resting membrane potentials and voltage-gated calcium channel (VGCC) function of SH-SY5Y human neuroblastoma cells cultured on the microbead array versus collagen-coated flat (2-D) substrates were evaluated by confocal microscopy with a potentiometric dye, tetramethylrhodamine methyl ester, and a calcium fluorescent indicator, Calcium Green-1. SH-SY5Y cells, differentiated with 1mM dibutyryl cAMP and 2.5 microM 5-bromodeoxyuridine, showed significant resting membrane potential establishment on the topographical scaffolds in a period of 13 days into differentiation, in contrast to the previously reported insignificant resting membrane potential establishment of the same cells within collagen hydrogels. On days 2, 8 and 13 into differentiation, cells on collagen-coated flat substrates developed resting membrane potentials of -6.0+/-19.5 mV (n=198), -30.5+/-19.9 mV (n=191) and -21.7+/-18.9 mV (n=308), in contrast to values for cells on 3-D scaffolds of -25.8+/-14.7 mV (n=112), -37.6+/-13.1 mV (n=120) and -28.7+/-12.2 mV (n=158), respectively. The development of VGCC function, as measured by percentage of cells responsive to 50 mM high K(+) depolarization, was significantly slower for cells on 3-D scaffolds (20.0% on day 13 into differentiation) than for cells on 2-D substrates (30.7% on day 8 into differentiation). The exaggerated 2-D cell calcium dynamics, in comparison with those of 3-D cells, is consistent with previous 2-D/3-D comparative studies. This study established the rationale and feasibility of the microbead array format for 3-D cell-based biosensing.

Human neuroblastoma (SH-SY5Y) cell culture and differentiation in 3-D collagen hydrogels for cell-based biosensing.

Cell-based three-dimensional systems are desirable in the field of high throughput screening assays due to their potential similarity to in vivo environment. We have used SH-SY5Y human neuroblastoma cells cultured in 3-D collagen hydrogel, confocal microscopy and immunofluorescence staining, to assess the merit of the system as a functional, cell-based biosensor. Our results show differences between 2-D and 3-D resting membrane potential development profile upon differentiation. There was no statistically significant difference in SH-SY5Y proliferation rate between 2-D monolayer and 3-D collagen culture formats. A large percentage of cells (2-D, 91.30% and 3-D, 84.93%) did not develop resting membrane potential value equal to or lower than -40 mV; instead cells exhibited a heterogeneous resting membrane potential distribution. In response to high K(+) (50 mM) depolarization, 3-D cells were less responsive in terms of increase in intracellular Ca(2+), in comparison to 2-D cells, supporting the hypothesis that 2-D cell calcium dynamics may be exaggerated. L-Type Ca(2+) expression levels based on staining results was inconsistent with Bay K 8644 channel activation results, strongly suggesting that either the majority of the channels were non-functional or could not be activated by Bay K 8644. In general, the results in this study confirm the depolarization-induced differences in intracellular calcium release when cultured using a 2-D versus a 3-D matrix.

The syntheses and in vivo biodistribution of novel boronated unnatural amino acids.

A series of boronated, unnatural amino acids were prepared and their biodistribution determined in melanoma bearing mice. The unnatural amino acids were prepared utilizing recently developed borylation. The majority of the syntheses utilize metal catalyzed additions of diboron agents to unsaturated carbonyl compounds. Biodistribution studies in mice bearing melanoma tumors indicated that all the boronated amino acids were taken up by the melanoma tumors. The data for the cyclic five-membered ring analogue, 1-amino-3-boronocyclopentanecarboxylic acid, was most striking, exhibiting a nearly 22:1 ratio of boron concentration for tumor to brain at the 2 h time point, dropping to 7.3 after 6 h. The tumor to blood and tumor to skin ratios were also quite high. It is important to note that all of the amino acids were synthesized as racemic and diastereomeric mixtures. Thus there is a high probability that a single enantiomer of 1-amino-3-boronocyclopentanecarboxylic acid might exhibit far higher selectivity.

[Inhibition of ATP-activated current by met-Enk in isolated DRG neurons of the rat].

The present study aimed to explore modulation of ATP-activated currents (I(ATP)) by met-Enk in rat DRG neurons. I(ATP) was recorded using the whole-cell patch clamp technique. The majority of the neurons examined responded to ATP (90.0 percent;, 45/50) with inward currents. In the 45 ATP sensitive neurons three kinds of responses to application of met-Enk were distinguished: (l) inward currents (29/45), (2) outward currents (9/45), and (3) no effect (7/45). Pretreatment with met-Enk (10(-9)~10(-5) mol/L) suppressed I(ATP) (10(-4) mol/L) in 29 neurons responding to met-Enk with inward currents. The inhibition by met-Enk of I(ATP) could be blocked by naloxone (10(-7) mol/L) in a concentration-dependent manner. Met-Enk of 10(-9), 10(-8), 10(-7), 10(-6) and 10(-5) mol/L suppressed I(ATP) by l3.2+/-5.4 percent; (n=5); 39.2+/-8.6 percent; (n=8), 54.l+/-8.6 percent; (n=8),43.3+/-7.9 percent; (n=7) and 43.l+/-7.9 percent; (n=7) (mean+/-MSE), respectively. A comparison of concentration - response relations of ATP with and without preapplication of met-Enk indicated that after pretreatment with met-Enk (10(-7) mol/L) the curve shifted downward markedly with a decrease of 25 percent; of the maximum value of I(ATP) and unchanged K(d) value. The suppression of I(ATP) by met-Enk was reversed as evidenced by intracellular dialysis of H-9 by using the repatch technique. Taken together, it is suggested that the inhibition by met-Enk of I(ATP) is caused by activation of opiate receptor, which eventually results in phosphorylation of ATP receptor, mediated by modulation of G protein coupling and intracellular signal transduction.

Comparison of the viscoelastic properties of normal hepatocytes and hepatocellular carcinoma cells under cytoskeletal perturbation.

The viscoelastic properties of both hepatocytes and hepatocellular carcinoma (HCC) cells were measured by means of a micropipette aspiration technique. Experimental results were analyzed with a three-element standard linear solid model, in which an elastic element, K1, is in parallel with a Maxwell element composed of another elastic element, K2, in series with a viscous element, mu. Further, we investigated the relevance of viscoelastic properties of these two types of cells to the cytoskeleton structures by treating cells with three cytoskeletal perturbing agents, namely cytochalasin D (CD), colchicine (Col) and vinblastine (VBL). The results showed that the elastic coefficients, but not viscous coefficient of HCC cells (K1 = 103.6 +/- 12.6 N m-2, K2 = 42.5 +/- 10.4 N m-2, mu = 4.5 +/- 1.9 Pa s, n = 30), were significantly higher than the corresponding values for hepatocytes (K1 = 87.5 +/- 12.1 N m-2, K2 = 33.3 +/- 10.3 N m-2, mu = 5.9 +/- 3.0 Pa s, n = 24). Upon treatment with CD, the viscoelastic coefficients of both hepatocytes and HCC cells decreased uniformly, with magnitudes for the decrease in elastic coefficients of HCC cells (K1: 68.7 to 81.7 N m-2, 66.3 to 78.9%; K2: 34.5 to 37.1 N m-2, 81.2 to 87.3%) larger than those for normal hepatocytes (K1: 42.6 to 49.8 N m-2, 48.7 to 56.9%; K2: 17.2 to 20.4 N m-2, 51.7 to 61.3%). There was a smaller decrease in the viscous coefficient of HCC cells (2.0 to 3.4 Pa s, 44.4 to 75.6%) than that for hepatocytes (3.0 to 3.9 Pa s, 50.8 to 66.1%). Upon treatment with Col and VBL, the elastic coefficients of hepatocytes generally increased or tended to increase while those of HCC cells decreased. The differences in either the pattern or the magnitude of the effect of cytoskeletal perturbing agent on the viscoelastic properties between HCC cells and hepatocytes might possibly reflect differences in the state of the cytoskeleton structure and function, or in the cells' sensitivity to perturbing agent treatment between these two types of cells. Changes in the viscoelastic properties of cancer cells might well affect tumor cell invasion and metastasis as well as interactions between tumor cells and their micro-mechanical environments.