A new high-throughput screening methodology for the discovery of cancer-testis antigen using multi-omics data

BACKGROUND

Cancer/testis antigens (CTAs), also known as tumor-specific antigens (TSAs) are specifically expressed in cancer cells and exhibit high immunogenicity, making them promising targets for immunotherapy and cancer vaccines.

METHODS

A new integrated high-throughput screening methodology for CTAs was proposed in this study through combining DNA methylation and RNA sequencing data. Briefly, the genes with increased transcript level and decreased DNA methylation were identified by multi-omics analysis. RNA sequencing studies in cell lines exposed to DNA methyltransferase (DNMT) inhibitors were performed to validate the inherent causal relationship between DNA hypomethylation and gene expression upregulation.

RESULTS

We proposed a new integrated high-throughput screening methodology for identification of CTAs using multi-omics analysis. In addition, we tested the feasibility of this method using gastric cancer (GC) as an example. In GC, we identified over 2000 primary candidate CTAs and ultimately identified 20 CTAs with significant tissue-specificity, including a testis-specific serine protease TESSP1/PRSS41. Integrated analysis confirmed that PRSS41 expression was reactivated in gastrointestinal cancers by promoter DNA hypomethylation at the CpG site (cg08104780). Additionally, DNA hypomethylation of PRSS41 predicted a poor prognosis in GC.

CONCLUSION

We propose a new high-throughput screening method for the identification of CTAs in cancer and validate its effectiveness. Our work emphasizes that serine protease PRSS41 is a novel TSA that is reactivated in GC due to promoter DNA hypomethylation.

Cancer-associated fibroblasts promote gastric cancer cell proliferation by paracrine FGF2-driven ribosome biogenesis

The cancer-associated fibroblast (CAF)-derived secretome plays critical roles in tumor progression by remodelling tumor microenvironment. Tumorigenesis is accompanied by the transformation of normal fibroblasts (NF) into CAF, leading to significant changes in their secretome. This work aims to identify the differential components of secretome between NFs and CAFs and reveal their functions in gastric cancer (GC). Firstly, our molecular typing studies and immune infiltration analysis showed that CAF infiltration level was increased and showed a significant association with clinical characteristics and poor prognosis of GC patients. Secondly, RNA-seq analysis revealed that a total of 1531 genes showed significant expression changes between NF and CAF. According to the annotation of the Human Protein Atlas (HPA) database, 147 genes encode secreted proteins, including FGF2. Particularly, the cell co-culture and RNA sequencing studies confirmed that exogenous recombinant FGF2 protein treatment promoted GC cell proliferation by enhancing ribosome biogenesis. The rescue assay showed that CAF-secreted FGF2 protein promotes GC cell growth and proliferation in a FGFR1-dependent manner. Our finding provides evidence that targeting blockade of CAF-derived FGF2 protein might be a promising treatment for GC.

Bacterial diversity in primary infected root canals of a Chinese cohort: analysis of 16 S rDNA sequencing

PURPOSE

To characterize the bacterial community in the primarily infected root canals.

METHODS

A total of 13 samples were collected from the primarily infected root canals. 16 S rDNA sequencing was performed to define bacterial community. Taxonomic annotation, bacterial hierarchical structures, community richness and diversity, and inter-subject variability of the bacterial community in the root canal samples were analyzed. Gender, age, and duration of the toothache-specific bacterial community associated with the patient groups were analyzed.

RESULTS

A total of 359 Species were annotated and identified in the whole study cohort. The Alpha diversity analysis showed that the species diversity and detection rate of the 13 samples were high, which reflected the authenticity of sequencing results. The Beta diversity analysis was used to compare the degree of difference between different root canal samples. The 13 samples were divided into two groups according to the results, group A was samples I1-I12, and group B was samples I13. The bacterial species of group A samples were analyzed with the clinical characteristics of patients, and it was found that gender, and duration specific differences in bacterial species, and there was no significant difference in species types among different ages of patients.

CONCLUSION

There were a wide diversity and inter-subject variability in the bacterial community in the primary infected root canals. While Porphyromonas gingivalis was the most abundant species, Fusobacterium nucleatum was the most variable species in the bacterial community of the root canal. The bacterial community at different taxonomic levels varied from sample to sample, despite consistent disease diagnoses. There was gender, duration-specific differences in the bacterial species in the primary infected root canals.

Fibromodulin overexpression drives oral squamous cell carcinoma via activating downstream EGFR signaling

Accumulating evidence has shown that fibromodulin (FMOD) plays a pivotal role in tumorigenesis and metastasis. However, the biological function of FMOD in oral squamous cell carcinoma (OSCC) remains largely unclear to date. In this study, we confirmed that FMOD was overexpressed and showed a significant association with malignant progression and lymph node metastasis in OSCC. Depletion of FMOD inhibited OSCC proliferation and metastasis in vitro and in vivo. RNA sequencing, western blotting, and rescue assays verified that FMOD exerted oncogenic roles in OSCC via activation of EGFR signaling. In addition, FMOD was proved to be a putative target gene of miR-338-3p. Taken together, FMOD overexpression due to the reduced level of miR-338-3p promotes OSCC by activating EGFR signaling. Our findings provide direct evidence that targeting FMOD could be a promising therapeutic strategy for OSCC patients.

Serine protease PRSS56, a novel cancer-testis antigen activated by DNA hypomethylation, promotes colorectal and gastric cancer progression via PI3K/AKT axis

BACKGROUND

Cancer/testis (CT) antigens/genes are usually overexpressed in cancers and exhibit high immunogenicity, making them promising targets for immunotherapy and cancer vaccines. The role of serine protease PRSS56 in cancers remains unknown to date.

METHODS

RNA sequencing studies were performed to screen CT genes in gastric cancer (GC) and colorectal cancer (CRC) cells exposed to DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5-AZA-CdR). Bioinformatics analysis was conducted to analyze the correlation between PRSS56 expression and DNA methylation. Functional experiments were performed to explore the biological function of PRSS56 in GC and CRC.

RESULTS

In this study, we identified the testis-specific serine proteases PRSS56 as a novel CT antigen. PRSS56 was frequently overexpressed in various cancers, especially in gastrointestinal cancer. PRSS56 expression was negatively associated with promoter DNA methylation level, and positively associated with gene body methylation level. PRSS56 expression was significantly activated in colorectal and gastric cancer cells exposed to DNA methyltransferase inhibitors. Importantly, our finding highlights that the decreased methylation level of the CpG site cg10242318 in the PRSS56 promoter region resulted in its overexpression in GC and CRC. Additionally, functional assays verified that PRSS56 overexpression activated PI3K-AKT signaling in GC and CRC.

CONCLUSION

Serine protease PRSS56 is a novel CT antigen that is reactivated in cancers by promoter DNA hypomethylation. PRSS56 functions oncogenic roles in GC and CRC by activating of PI3K/AKT axis. Our results presented here represent the first data on the function of the serine protease PRSS56 in cancers.

Heterogeneity and plasticity of epithelial-mesenchymal transition (EMT) in cancer metastasis: Focusing on partial EMT and regulatory mechanisms

Epithelial-mesenchymal transition (EMT) or mesenchymal-epithelial transition (MET) plays critical roles in cancer metastasis. Recent studies, especially those based on single-cell sequencing, have revealed that EMT is not a binary process, but a heterogeneous and dynamic disposition with intermediary or partial EMT states. Multiple double-negative feedback loops involved by EMT-related transcription factors (EMT-TFs) have been identified. These feedback loops between EMT drivers and MET drivers finely regulate the EMT transition state of the cell. In this review, the general characteristics, biomarkers and molecular mechanisms of different EMT transition states were summarized. We additionally discussed the direct and indirect roles of EMT transition state in tumour metastasis. More importantly, this article provides direct evidence that the heterogeneity of EMT is closely related to the poor prognosis in gastric cancer. Notably, a seesaw model was proposed to explain how tumour cells regulate themselves to remain in specific EMT transition states, including epithelial state, hybrid/intermediate state and mesenchymal state. Additionally, this article also provides a review of the current status, limitations and future perspectives of EMT signalling in clinical applications.

Cancer-associated fibroblast-secreted IGFBP7 promotes gastric cancer by enhancing tumor associated macrophage infiltration via FGF2/FGFR1/PI3K/AKT axis

We previously reported that IGFBP7 plays a role in maintaining mRNA stability of oncogenic lncRNA UBE2CP3 by RNA-RNA interaction in gastric cancer (GC). Clinical cohort studies had implied an oncogenic role of IGFBP7 in GC. However, the molecular mechanism of IGFBP7 in GC progression remains unknown. In this study, clinical analysis based on two independent cohorts showed that IGFBP7 was positively associated with poor prognosis and macrophage infiltration in GC. Loss-of-function studies confirmed the oncogenic properties of IGFBP7 in regulating GC cell proliferation and invasion. Mechanismly, IGFBP7 was highly expressed in cancer-associated fibroblasts (CAF) and mesenchymal cells, and was induced by epithelial-to-mesenchymal transition (EMT) signaling, since its expression was increased by TGF-beta treatment and reduced by overexpression of OVOL2 in GC. RNA sequencing, qRT-PCR, ELISA assay showed that IGFBP7 positively regulated FGF2 expression and secretion in GC. Transcriptome analysis revealed that FGFR1 was downregulated in M1 polarization but upregulated in M2 polarization. Exogenous recombinant IGFBP7 treatment in macrophages and GC cells further identified that IGFBP7 promotes tumor associated macrophage (TAM) polarization via FGF2/FGFR1/PI3K/AKT axis. Our finding here represented the first evidence that IGFBP7 promotes GC by enhancing TAM/M2 macrophage polarization through FGF2/FGFR1/PI3K/AKT axis.

Genome-wide association studies identify miRNA-194 as a prognostic biomarker for gastrointestinal cancer by targeting ATP6V1F, PPP1R14B, BTF3L4 and SLC7A5

Background

The dysregulated genes and miRNAs in tumor progression can be used as biomarkers for tumor diagnosis and prognosis. However, the biomarkers for predicting the clinical outcome of gastrointestinal cancer (GIC) are still scarce.

Methods

Genome-wide association studies were performed to screen optimal prognostic miRNA biomarkers. RNA-seq, Ago-HITS-CLIP-seq, western blotting and qRT-PCR assays were conducted to identify target genes of miR-194. Genome-wide CRISPR-cas9 proliferation screening analysis were conducted to distinguish passenger gene and driver gene.

Results

A total of 9 prognostic miRNAs for GIC were identified by global microRNA expression analysis. Among them, miR-194 was the only one miRNA that significantly associated with overall survival, disease-specific survival and progress-free interval in both gastric, colorectal and liver cancers, indicating miR-194 was an optimal prognostic biomarker for GIC. RNA-seq analysis confirmed 18 conservative target genes of miR-194. Four of them, including ATP6V1F, PPP1R14B, BTF3L4 and SLC7A5, were directly targeted by miR-194 and required for cell proliferation. Cell proliferation assay validated that miR-194 inhibits cell proliferation by targeting ATP6V1F, PPP1R14B, BTF3L4 and SLC7A5 in GIC.

Conclusion

In summary, miR-194 is an optimal biomarker for predicting the outcome of GIC. Our finding highlights that miR-194 exerts a tumor-suppressive role in digestive system cancers by targeting ATP6V1F, PPP1R14B, BTF3L4 and SLC7A5.

Coordination of pancreatic islet rhythmic activity by delayed negative feedback

Secretion of insulin from the pancreas is pulsatile, driven by intrinsic oscillations within individual islets of Langerhans. The secretions are coordinated among the many islets distributed throughout the pancreas producing a synchronized rhythm in vivo that is essential for maintaining normal glucose levels. One hypothesized mechanism for the coordination of islet activity is negative feedback, whereby sequestration of glucose in response to elevated insulin leads to a reduction in the blood glucose level that is sensed by the islet population. This global signal of glucose then coordinates the individual islets. In this study, we tested how this coordination mechanism is affected by time delays in the negative feedback, using a microfluidic system to monitor Ca2+ levels in a small population of islets and implementing glucose control through a negative feedback system. We found that islet synchronization occurs even with time delays in the feedback of up to 7 min. We also found that a second, slower closed-loop oscillation period is produced during delayed feedback in which islet oscillations are clustered into episodes. The period of this second oscillatory mode increases with the time delay and appears to be a second stable behavior that coexists with the faster synchronized oscillation. The general conclusion is that islet coordination through negative feedback is a viable means of islet coordination that is robust to delays in the timing of the feedback, and could complement other potential coordination mechanisms such as entrainment by pancreatic ganglia.NEW & NOTEWORTHY Insulin secretion from islets of Langerhans is rhythmic, and these rhythms are coordinated to produce oscillatory plasma insulin levels. Using a combination of microfluidics and computational modeling, we demonstrate that coordination can occur through negative feedback of the type provided by the liver, even if that feedback is delayed by several minutes. We also demonstrate that a second, slower, mode of oscillations can occur when feedback is delayed where faster oscillations are grouped into episodes.

Improved repair of rabbit calvarial defects with hydroxyapatite/chitosan/polycaprolactone composite scaffold-engrafted EPCs and BMSCs

Endothelial progenitor cells (EPCs) expressing vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) and bone marrow mesenchymal stem cells (BMSCs) expressing endogenous bone morphogenetic protein-2 (BMP-2) play the important role in new bone formation. This study investigated the effects of a porous hydroxyapatite (HA)/chitosan (CS)/polycaprolactone (PCL) composite scaffold-engrafted EPCs and BMSCs on the expression of BMP-2, VEGF, and PDGF in the calvarial defect rabbit model in vivo. It showed that a three-dimensional composite scaffold was successfully constructed by physical interaction with a pore size of 250 μm. The HA/CS/PCL scaffold degraded slowly within 10 weeks and showed non-cytotoxicity. By X-ray, micro-CT examination, and H&E staining, compared with the HA/CS/PCL group, HA/CS/PCL + EPCs, HA/CS/PCL + BMSCs, and HA/CS/PCL + EPCs + BMSCs groups performed a more obvious repair effect, and the dual factor group presented particularly significant improvement on the percentages of bone volume at week 4 and week 8, with evident bone growth. Osteogenesis marker (BMP-2) and vascularization marker (VEGF and PDGF) expression in the dual factor group were much better than those of the HA/CS/PCL control group and single factor groups. Collectively, the HA/CS/PCL composite scaffold-engrafting EPCs and BMSCs is effective to repair calvarial defects by regulating endogenous expression of BMP-2, VEGF, and PDGF. Thus, this study provides important implications for the potential clinical application of biomaterial composite scaffold-engrafted engineering cells.

A Pan-Cancer Analysis Reveals the Prognostic and Immunotherapeutic Value of Stanniocalcin-2 (STC2)

Background: Stanniocalcin-2 (STC2) is a secreted glycoprotein which plays an important role in regulating the homeostasis of calcium, glucose homeostasis, and phosphorus metastasis. Accumulating evidence suggests that STC2 is implicated in cancer mechanisms. However, the effects of STC2 on cancer development and progression across pan-cancer are not yet completely known.

Methods: Data were downloaded from The Cancer Genome Atlas database to obtain differentially expressed genes significantly associated with prognosis (key genes). A gene was selected for subsequent correlation studies by integrating the significance of prognosis and the time-dependent ROC curve. Gene expression of different tumor types was analyzed based on the UCSC XENA website. Furthermore, our study investigated the correlation of STC2 expression between prognosis, immune cell infiltration, immune checkpoint genes (ICGs), mismatch repair genes (MMRs), tumor mutation burden (TMB), microsatellite instability (MSI), and drug sensitivity in various malignant tumors. Gene set enrichment analysis (GSEA) was conducted for correlated genes of STC2 to explore potential mechanisms.

Results: A total of 3,429 differentially expressed genes and 397 prognosis-related genes were identified from the TCGA database. Twenty-six key genes were found by crossing the former and the latter, and the highest risk gene, STC2, was selected for subsequent correlation studies. STC2 had good diagnostic performance for HNSCC, and was closely related to the survival status and clinicopathological stage of HNSCC patients. In pan-cancer analysis, STC2 was upregulated in 20 cancers and downregulated in seven cancers. STC2 overexpression was overall negatively correlated with overall survival, disease-free survival, disease-specific survival, and progress-free survival. STC2 was profoundly correlated with the tumor immune microenvironment, including immune cell infiltration, ICGs, MMRs, TMB, and MSI. Moreover, STC2 was significantly negatively correlated with the sensitivity or resistance of multiple drugs.

Conclusion: STC2 was a potential prognostic biomarker for pan-cancer and a new immunotherapy target.

Convalescent plasma is of limited clinical benefit in critically ill patients with coronavirus disease-2019: a cohort study

Background

Recently, convalescent plasma (CP) transfusion was employed for severe or critically ill patients with coronavirus disease-2019. However, the benefits of CP for patients with different conditions are still in debate. To contribute clinical evidence of CP on critically ill patients, we analyze the characteristics and outcomes of patients with or without CP transfusion.

Methods

In this cohort study, 14 patients received CP transfusion based on the standard treatments, whereas the other 10 patients received standard treatments as control. Clinical characteristics and outcomes were analyzed. The cumulative survival rate was calculated by Kaplan–Meier survival analysis.

Results

Data analysis was performed on 24 patients (male/female: 15/9) with a median age of 64.0 (44.5–74.5) years. Transient fever was reported in one patient. The cumulative mortality was 21% (3/14) in patients receiving CP transfusion during a 28-day observation, whereas one dead case (1/10) was reported in the control group. No significant difference was detected between groups in 28-day mortality (P = 0.615) and radiological alleviation of lung lesions (P = 0.085).

Conclusion

In our current study, CP transfusion was clinically safe based on the safety profile; however, the clinical benefit was not significant in critically ill patients with more comorbidities at the late stage of disease during a 28-day observation.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03028-5.

PEEK‑biphasic bioceramic composites promote mandibular defect repair and upregulate BMP‑2 expression in rabbits

The present study aimed to investigate whether bone morphogenetic protein-2 (BMP-2) was involved in the repair of mandibular defects using polyether-ether-ketone biphasic bioceramic (PEEK-BBC) composites in rabbits. PEEK-BBC composites with abundant and interconnected pores were prepared by calcination and characterized by scanning electron microscope. A mandibular defect model in rabbits was established using dental grinder to produce a square hole. A total of 60 rabbits were divided into four groups: Control, sham, surgery, and PEEK. In the PEEK group, the holes were filled with the PEEK-BBC composite stents. In the surgery group, the holes were produced but not filled with the composite stents. In the sham group, only the molar grooves were exposed and grinding was not performed. Animals without any treatment served as the control group. The success rate of model establishment was 100%. At 4, 8, and 16 weeks after the model was established, samples were collected from the molding sites. Bone repair was evaluated by H&E staining and Goldner trichrome staining. Bone structures in both control and sham groups were intact. A small number of osteocytes were observed in the surgery group. However, in the PEEK group, osteocytes were already evidently present in the composites at 4 weeks after surgery. At 8 and 16 weeks, there were large numbers of osteocytes in the pores of the composites. The mRNA and protein expression levels of BMP-2 were determined by reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. The mRNA and protein expression levels of BMP-2 between the control and sham groups were similar and were continuously stable. However, following defect treatment, BMP-2 mRNA and protein expression was upregulated, which was enhanced by the PEEK-BBC composites. In conclusion, PEEK-BBC composites promoted the growth of osteocytes and repaired mandibular defects in rabbits, potentially via the upregulation of BMP-2 expression.

Tooth loss and cancer risk: a dose-response meta analysis of prospective cohort studies

Conflicting results to identify the relationship between tooth loss and cancer risk. Therefore, a dose-response meta-analysis was performed to clarify and quantitative assessed the correlation between tooth loss and cancer risk. Up to March 2017, 25 observational epidemiological studies were included in current meta-analysis. Tooth loss was significantly associated with a higher risk of cancer. Additionally, tooth loss was associated with significantly a higher risk of esophageal cancer, gastric cancer, head and neck cancer, colorectal cancer, pancreas cancer, lung cancer, prostate cancer, bladder cancer and hematopoietic cancer. Subgroup analysis showed consistent findings. Furthermore, a significant dose-response relationship was observed between tooth loss and cancer risk. Increasing per 10 of tooth loss was associated with a 9% increment of cancer risk, 14% increment of esophageal cancer risk, 9% increment of gastric cancer risk, 31% increment of head and neck cancer risk, 4% increment of colorectal cancer risk, 7% increment of pancreas cancer risk, 19% increment of lung cancer risk, 2% increment of bladder cancer risk and 3% increment of hematopoietic cancer risk. Considering these promising results, tooth loss might be harmful for health. Large sample size, different ethnic population and different cancer type are warranted to validate this association.

Nonsteroidal anti-inflammatory drugs using and risk of head and neck cancer: a dose-response meta analysis of prospective cohort studies

Conflicting results identifying the relationship between nonsteroidal anti-inflammatory drugs using and head and neck cancer risk. Therefore, we performed this meta-analysis to clarify and quantitative assessed the relationship between nonsteroidal anti-inflammatory drugs using and head and neck cancer risk. Up to March 2017, 11 original publications were included in this meta-analysis. Our results showed statistically significant association between nonsteroidal anti-inflammatory drugs using and head and neck cancer risk reduction. Subgroups analysis indicated that Aspirin, COX 2 inhibitors, Ibuprofen and Other NSAIDs were associated with a significantly risk reduction of head and neck cancer. Furthermore, nonsteroidal anti-inflammatory drugs using was associated with a significantly lower risk of oral and oropharynx cancer, larynx cancer and hypopharynx cancer. In addition, increasing nonsteroidal anti-inflammatory drugs using (per 2 prescriptions/week increment) was associated with a 4% reduction in head and neck cancer risk, 5% reduction of aspirin using and 6% reduction of other nonsteroidal anti-inflammatory drugs using. Considering these promising results, increasing nonsteroidal anti-inflammatory drugs using might provide health benefits. More studies and large sample size are warranted to validate this association.

Facile, tunable, and SERS-enhanced HEPES gold nanostars

The facile, green synthesis of gold nanostars (AuNSs) with tunable branch lengths for SERS applications.

TRAIL-expressing gingival-derived mesenchymal stem cells inhibit tumorigenesis of tongue squamous cell carcinoma

Recent research has verified that mesenchymal stromal/stem cells (MSCs) derived from bone marrow or adipose tissues can migrate toward a variety of tumors. In this study, we explored whether human gingival-derived MSCs (G-MSCs) can migrate toward tongue squamous cell carcinoma (TSCC) and evaluated the antitumor effect of engineered G-MSCs in expressing and delivering the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). An in vitro cell migration assay with Transwell plates showed that human G-MSCs can migrate toward TSCC cell lines (Tca8113 and Cal27). Then, human G-MSCs, as a type of cell-based vehicle, were transduced with full-length TRAIL and enhanced green fluorescent protein reporter genes by the lentivirus (LV) system (G-MSCs with full-length TRAIL; G-MSCFLT). Tca8113 and Cal27 were co-cultured with G-MSCFLT, respectively, to evaluate the function of G-MSCFLT on tumor cells in vitro. This resulted in G-MSCFLT's inducing a great number of tumor cell necrosis and apoptosis. Meanwhile, in vivo antitumor assays were performed by administering G-MSCFLT to nude mice locally and systematically (mixed injection with tumor cells and tail vein injection). This showed that G-MSCFLT can reduce or even inhibit TSCC growth regardless of the method of administration, especially when the mixed injection of tumor cells and G-MSCFLT was at a ratio of 1:1, which showed no tumor formation. Furthermore, this verified that G-MSCFLT migrated toward TSCC in quantity. These data emphasize the effectiveness of G-MSCs as a vehicle for cell-based gene therapy and the antitumor activity of TRAIL-expressing G-MSCs.

CYP2E1 Rsa I/Pst I polymorphism and esophageal cancer risk: a meta-analysis based on 1,088 cases and 2,238 controls

The common functional CYP2E1 Rsa I/Pst I polymorphism may influence the risk of esophageal cancer. However, the published results are conflicting. We therefore conducted a meta-analysis comprised of 11 published case-control studies with 1,088 cases and 2,238 controls. Odds ratios (ORs) with 95% confidence interval (CIs) were used to assess the strength of the association. Overall, the pooled ORs were 0.53 (95% CI = 0.31-0.89, P (heterogeneity) < 0.001) and 0.57 (95% CI = 0.34-0.96, P (heterogeneity) < 0.001), for the heterogeneity c1/c2 and c2 allele carriers (c1/c2 + c2/c2) compared with the homozygous c1/c2, respectively. In subgroup analysis by race, the same significant risks were found among Asians (for c2 vs. c1: OR = 0.64, 95% CI = 0.43-0.95, P (heterogeneity) < 0.001; for c1/c2 vs. c1/c1: OR = 0.48, 95% CI = 0.28-0.82, P (heterogeneity) < 0.001; for c1/c2 + c2/c2 vs. c1/c1: OR = 0.51, 95% CI = 0.30-0.86, P (heterogeneity) < 0.001). In conclusion, our meta-analysis demonstrates that CYP2E1 Rsa I/Pst I c2 allele may be a decreased risk factor for developing esophageal cancer among Asians populations.

[Induction of drug resistance in Tca8113 cell line by exposing to chemotherapy drug]

OBJECTIVE

To study the drug resistance changes in Tca8113 cell lines by exposing to carboplatin.

METHODS

The concentration of carboplatin added to Tca8113 cells was increased gradually and continually, which was to induce the carhoplatin-resistance in Tca8113 cells. The sensibility to drugs of the cells was analyzed by MTT method. Immunocytochemistry and RT-PCR were utilized to examine the expression of multidrug resistance proteins and genes.

RESULTS

After exposing to carboplatin, the Tca8113/CBP cells had higher drug-resistance to CBP, MTX, PYM, VCR and higher expression of MRP, GST-pi than Tca8113 cells.

CONCLUSION

Multidrug resistance of Tca8113/CBP is associated with over expression of MRP, GST-pi and MDR. Tca8113/CBP can provide an ideal model for multidrug resistance research.

Dietary fish oil supplementation adversely affects cortical bone morphology and biomechanics in growing rabbits

Despite substantial evidence that fish oil-derived (n-3) polyunsaturated fatty acids (PUFA) may protect against cardiovascular disease, the effects of supplements containing (n-3) PUFA on the skeletal system are unknown. Here we investigated how a diet supplemented with 10 g/100 g fish oil affected tibial cortical morphology and mechanical properties in weanling rabbits. Rabbits were subdivided into a normal control (n = 10), a fish oil (n = 20), and a pair-fed (n = 20) group. The pair-fed group was energy restricted to match average body mass of the fish oil group. At completion of the 40 day dietary intervention, control rabbits were significantly heavier than the other two groups. Comparison between control and pair-fed rabbits revealed that energy restriction alone (30%) did not induce significant changes in tibial middiaphyseal morphology, but tibial longitudinal growth was significantly impaired. Most tibial mechanical properties were significantly degraded by energy restriction. Fish oil-supplemented rabbits had significantly smaller middiaphyseal areal properties and shorter tibiae than pair-fed rabbits. Tibial structural properties were significantly reduced in fish oil-fed rabbits, but tibial stress at the proportional limit (material property) was not significantly affected. Our data suggest that 10% fish oil supplementation in the presence of modest vitamin E supplementation can have detrimental effects on the skeleton of rapidly growing rabbits.

Measurement of biological activity of somatotropin in hypophysectomized rats

AIM

To develop a method for measurement of biological activity of recombinant DNA-derived somatotropin (rhGH).

METHODS

The effects of varying the route, frequency and period of administration of GH, the sex of test animals on the biological responses, body weight gain (BWG), and tibial epiphyseal width (TEW), of hypophysectomized (Hypox) rats were compared, respectively. 4-d BWG, 6-d BWG, and 6-d TEW tests were carried out simultaneously in the same group of Hypox rats to determine the biopotency of GH preparations according to a parallel line bioassay (6-point assay). The final result was chosen from the test which had smaller values for the index of precision (lambda) and the average rate of fiducial limits (ARFL) than other tests.

RESULTS

No significant differences in the responses between male and female rats, between sc and im, once daily and twice daily injections of bGH were found. But the BWG and TEW of Hypox rats injected with 0.045 and 0.135 IU.d-1 of bGH for 6 d were significantly greater than that for 4 d. Both 4-d BWG test and 6-d BWG test in the range from 0.020 to 0.500 IU.d-1 had values for lambda = 0.0660 and 0.1747, and for r = 0.9000 and 0.9237, respectively. Three estimates of rhGH preparation compared with the International Standard for somatotropin (IShGH), 4.6132, 3.9829, and 4.8023 IU/ampoule, were obtained separately from 4-d BWG test, 6-d BWG test and 6-d TEW test. And the result from 6-d BWG test was reported finally because it had smaller values for lambda and ARFL (0.0608 and 37.907%) than other two tests.

CONCLUSION

Both BWG test and TEW test can be carried out simultaneously in the same group of Hypox rats. 6-d BWG test seemed to be more suitable for potency determination of GH preparations than 4-d BWG test and 6-d TEW test.

Administration of systemic matrix metalloproteinase inhibitors maintains bone mechanical integrity in adjuvant arthritis

OBJECTIVE

To evaluate the influence of systemic tetracycline derived antimetalloproteinase compounds on bone morphology and mechanical integrity.

METHODS

Male Lewis rats (n = 78) were randomly assigned to one of 10 groups, comprising controls, adjuvant arthritis (AA), and adjuvant arthritis with various combinations of 2 chemically modified, non-antimicrobial tetracycline derivatives (CMT3 or CMT8) with either of 2 nonsteroidal antiinflammatory agents (flurbiprofen or tenidap). After AA induction (23 days), pharmacological efficacy was assessed by inflammatory indices, body mass changes, joint radiological destruction scores, and pyridinoline collagen derived crosslinks. The structural and material properties of the rat femoral neck were assessed biomechanically.

RESULTS

Neither CMT had an antiinflammatory effect, but flurbiprofen and tenidap (alone or together with either CMT) significantly reduced joint inflammation. Pyridinoline excretion increased markedly in untreated AA, but was substantially normalized by either CMT3 alone or by CMT8 with flurbiprofen. AA produced significant deleterious effects on femoral neck structure and mechanical properties. Administration of either CMT, however, had positive effects on the amount of bone and the biomechanical properties of rat femoral neck, but not the mineralization of the bone in the rat femoral neck.

CONCLUSION

These data suggest that tetracycline derived antimetalloproteinase compounds can significantly and positively influence bone mechanical integrity associated with inhibition of collagen breakdown.

Increased regional vascular albumin permeation in the rat during anaphylaxis

The changes in vascular albumin permeation induced by systemic anaphylaxis were studied simultaneously in 21 different tissues of the same animal. Before Ag challenge sensitized rats were injected i.v. with 125I-albumin (test tracer), 51Cr-RBC (vascular space marker) and 57Co-EDTA (extravascular space marker). The index of vascular permeation used was the tissue to blood isotope ratio (tbir), which was obtained by dividing the ratio of 125I/51Cr counts in each tissue by the ratio of the same isotopes in the arterial blood sample. After Ag challenge, the increase in the tbir varied considerably among the different tissues. The most pronounced increase was noted in the lymph node (ninefold) followed by the aorta and mesentery (six- to sevenfold) and the various parts of the gastrointestinal tract (four- to sixfold). In the skin less than skeletal muscle less than lung less than liver and eye two- to fourfold increases occurred. Relatively minor increases in albumin permeation (less than twofold) were observed in the brain less than kidney less than heart and less than spleen. The testis was the only organ in which no significant change occurred. For some of the tissues there was also an increase in the tbir for 57Co/51Cr (an index of the extracellular fluid space) suggesting edema formation. The highest increase was noted in the aorta (fourfold). Minor increases occurred in the atrium of the heart, stomach, duodenum, and lymph nodes. There was also a 36% increase in hematocrit. Therefore, systemic anaphylaxis caused extensive extravasation of albumin and hemoconcentration.

Increased regional vascular albumin permeation in the rat during anaphylaxis

The changes in vascular albumin permeation induced by systemic anaphylaxis were studied simultaneously in 21 different tissues of the same animal. Before Ag challenge sensitized rats were injected i.v. with 125I-albumin (test tracer), 51Cr-RBC (vascular space marker) and 57Co-EDTA (extravascular space marker). The index of vascular permeation used was the tissue to blood isotope ratio (tbir), which was obtained by dividing the ratio of 125I/51Cr counts in each tissue by the ratio of the same isotopes in the arterial blood sample. After Ag challenge, the increase in the tbir varied considerably among the different tissues. The most pronounced increase was noted in the lymph node (ninefold) followed by the aorta and mesentery (six- to sevenfold) and the various parts of the gastrointestinal tract (four- to sixfold). In the skin less than skeletal muscle less than lung less than liver and eye two- to fourfold increases occurred. Relatively minor increases in albumin permeation (less than twofold) were observed in the brain less than kidney less than heart and less than spleen. The testis was the only organ in which no significant change occurred. For some of the tissues there was also an increase in the tbir for 57Co/51Cr (an index of the extracellular fluid space) suggesting edema formation. The highest increase was noted in the aorta (fourfold). Minor increases occurred in the atrium of the heart, stomach, duodenum, and lymph nodes. There was also a 36% increase in hematocrit. Therefore, systemic anaphylaxis caused extensive extravasation of albumin and hemoconcentration.

Role of leukotrienes in vascular changes in the rat mesentery and skin in anaphylaxis

The role of leukotrienes and other mediators of vascular changes in anaphylaxis were studied in rats sensitized with monoclonal anti-DNP IgE and challenged with DNP-BSA. Microvascular changes in the mesentery were followed by intravital fluorescent microscopy and in the skin by exudation of Evans blue dye. Administration of Ag i.v. caused a marked increase in the peristaltic movement of the intestine, plasma exudation, and arteriolar constriction in the mesentery. The microvascular changes were accompanied by a profound fall in blood pressure, which was biphasic. The first phase lasted for approximately 2 min. The second phase was very prolonged and the hypotension was still maintained 40 min after Ag challenge. The changes observed were dose dependent with regard to Ag. Intradermal application of Ag resulted in dose-dependent extravasation of Evans blue dye in the skin. Plasma exudation was partially inhibited by pyrilamine and methysergide. However, their effect seemed to be more pronounced in the skin than in the mesentery. The leukotriene D4-R antagonist L-649,923 and the 5-lipoxygenase inhibitor ONO-LP-049, alone or in combination with other inhibitors, did not alter the plasma leakage in the skin. In the mesentery, the leukotriene antagonists alone had a moderate effect on vascular permeability. However, the combination of these agents with pyrilamine completely inhibited macromolecular extravasation. The hypotension was modulated by the antihistamines as well as the leukotriene and serotonin antagonists. Pyrilamine inhibited the first phase and the second phase. The major effect of methysergide was a decrease in the duration of the hypotension. This was especially evident when it was administered in combination with other inhibitors. The leukotriene antagonists when given alone had moderate effects on the blood pressure changes. However, in combination with pyrilamine, the hypotension was substantially reduced. Leukotrienes appeared to be important mediators of the vascular changes in the mesentery but not in the skin (passive cutaneous anaphylaxis). They markedly potentiated the action of histamines.

Role of leukotrienes in vascular changes in the rat mesentery and skin in anaphylaxis

The role of leukotrienes and other mediators of vascular changes in anaphylaxis were studied in rats sensitized with monoclonal anti-DNP IgE and challenged with DNP-BSA. Microvascular changes in the mesentery were followed by intravital fluorescent microscopy and in the skin by exudation of Evans blue dye. Administration of Ag i.v. caused a marked increase in the peristaltic movement of the intestine, plasma exudation, and arteriolar constriction in the mesentery. The microvascular changes were accompanied by a profound fall in blood pressure, which was biphasic. The first phase lasted for approximately 2 min. The second phase was very prolonged and the hypotension was still maintained 40 min after Ag challenge. The changes observed were dose dependent with regard to Ag. Intradermal application of Ag resulted in dose-dependent extravasation of Evans blue dye in the skin. Plasma exudation was partially inhibited by pyrilamine and methysergide. However, their effect seemed to be more pronounced in the skin than in the mesentery. The leukotriene D4-R antagonist L-649,923 and the 5-lipoxygenase inhibitor ONO-LP-049, alone or in combination with other inhibitors, did not alter the plasma leakage in the skin. In the mesentery, the leukotriene antagonists alone had a moderate effect on vascular permeability. However, the combination of these agents with pyrilamine completely inhibited macromolecular extravasation. The hypotension was modulated by the antihistamines as well as the leukotriene and serotonin antagonists. Pyrilamine inhibited the first phase and the second phase. The major effect of methysergide was a decrease in the duration of the hypotension. This was especially evident when it was administered in combination with other inhibitors. The leukotriene antagonists when given alone had moderate effects on the blood pressure changes. However, in combination with pyrilamine, the hypotension was substantially reduced. Leukotrienes appeared to be important mediators of the vascular changes in the mesentery but not in the skin (passive cutaneous anaphylaxis). They markedly potentiated the action of histamines.