Screening of novel serum biomarkers for gastric cancer in coastal populations using a protein microarray.

Gastric cancer (GC) has high rates of morbidity and mortality, and this phenomenon is particularly evident in coastal regions where local dietary habits favor the consumption of pickled foods such as salted fish and vegetables. In addition, the diagnosis rate of GC remains low due to the lack of diagnostic serum biomarkers. Therefore, in this study, we aimed to identify potential serum GC biomarkers for use in clinical practice. To identify candidate biomarkers of GC, 88 serum samples were first screened using a high-throughput protein microarray to measure the levels of 640 proteins. Then, 333 samples were used to validate the potential biomarkers using a custom antibody chip. ELISA, western blot, and immunohistochemistry were then used to verify the expression of the target proteins. Finally, logistic regression was performed to select serum proteins for the diagnostic model. As a result, five specific differentially expressed proteins, TGFß RIII, LAG-3, carboxypeptidase A2, Decorin and ANGPTL3, were found to have the ability to distinguish GC. Logistic regression analysis showed that the combination of carboxypeptidase A2 and TGFß RIII had superior potential for diagnosing GC (area under the ROC curve [AUC] = 0.801). The results suggested that these five proteins alone and the combination of carboxypeptidase A2 and TGFß RIII may be used as serum markers for the diagnosis of GC.

LINC00520 up-regulates SOX5 to promote cell proliferation and invasion by miR-4516 in human hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common human cancers. Long non-coding RNA (lncRNA) has been demonstrated to play an important role in regulating tumor development. The current study aims to explore the specific role of LINC00520 during HCC progression. The present study identified that LINC00520 was upregulated in HCC tissues and indicated poor patient survival. Overexpression of LINC00520 promoted HCC cell proliferation, migration and invasion, while LINC00520 downregulation led to the opposite effects. Besides, LINC00520 knockdown was found to inhibit tumor growth in vivo. Furthermore, LINC00520 acted as a sponge of miR-4516 to regulate SRY-related high mobility group box 5 (SOX5). In addition, the inhibition of miR-4516 partly reversed the inhibitory effect of LINC00520 silencing on HCC cell proliferation, migration and invasion. In conclusion, the inhibition of LINC00520 suppressed HCC cell proliferation, migration and invasion through mediating miR-4516/SOX5 axis. Therefore, our study provides a basis for the development of treatment strategies for HCC.

LINC00491 promotes cell growth and metastasis through miR-324-5p/ROCK1 in liver cancer.

BACKGROUND: LINC00491 was involved in some tumors development, but its function in liver cancer has not been reported. This study aimed to investigate LINC00491 expression and function in liver cancer progression. METHODS: Sixty liver cancer cases were enrolled. LINC00491, miR-324-5p and rho-associated kinase 1 (ROCK1) expression in liver cancer patients and cells were detected by quantitative reverse transcription-polymerase chain reaction and Western blot. HUH-7 and SK-Hep-1 cells were transfected to modulate LINC00491, miR-324-5p and ROCK1 expression. Cell counting kit-8 assay, colony formation assay, wound healing assay, Transwell experiment, Tunel assay and flow cytometry were performed to detected HUH-7 and SK-Hep-1 cells proliferation, migration, invasion, apoptosis and cell cycle. Biotin-RNA pull-down assay and Dual-Luciferase Reporter Assay was performed to detect the binding among LINC00491, miR-324-5p and ROCK1. Xenograft tumor and lung metastasis was performed using nude mice. Xenograft tumor and lung tissues of mice were experienced immunohistochemistry and hematoxylin-eosin staining. RESULTS: LINC00491 was highly expressed in liver cancer cases, associating with poor prognosis. si-LINC00491 inhibited proliferation, colony formation, invasion, migration, and induced cell cycle G1 arrest and apoptosis in HUH-7 and SK-Hep-1 cells. LINC00491 overexpression showed opposite effects. LINC00491 promoted ROCK1 expression by reducing miR-324-5p. miR-324-5p up-regulation or ROCK1 knockdown reversed LINC00491 promotion on liver SK-Hep-1 cells malignant phenotype. LINC00491 facilitated xenograft tumor growth and lung metastasis in mice. CONCLUSION: LINC00491 was highly expressed in liver cancer patients, associating with poor prognosis. LINC00491 facilitated liver cancer progression by sponging miR-324-5p/ROCK1. LINC00491 might be a potential treatment target of liver cancer.

Downregulation of hsa_circ_0001681 suppresses epithelial-mesenchymal transition in thyroid carcinoma via targeting to miR-942-5p/TWIST1 signaling pathway.

Thyroid carcinoma (TC) seriously threatens the health and safety of patients, and the treatment target of it still is poor. RT-qPCR and Western blot were carried out to detect the expression of genes and proteins, respectively. Cell proliferation was confirmed using colony formation assay. Transwell assay were performed to measure the cell migration and invasion. Besides, luciferase reporter assay was accomplished to ensure the target relationship between miR-942-5p and TWIST1 mRNA as well as hsa_circ_0001681. Here, we proved that hsa_circ_0001681 was increased in TC, and located majorly in the cytoplasm of TC cells. However,  miR-942-5p was decreased in TC, and was negatively correlated with hsa_circ_0001681 expression. Knockdown of hsa_circ_0001681 significantly repressed the proliferation, migration, invasion and EMT of TC cells. We also found that the process of hsa_circ_0001681 silencing limited EMT, which was obstructed by TWIST1 increasing. Moreover, hsa_circ_0001681 acted as a miRNA sponge and completed with TWIST1 mRNA for binding to miR-942-5p, thus downregulation of hsa_circ_0001681 repressed EMT and subsequent malignant phenotype of TC cells through targeting miR-942-5p/TWIST1 signaling pathway. Finally, the studies in vivo showed that decreasing of hsa_circ_0001681 effectively inhibited the growth of tumor via repressing EMT by regulating miR-942-5p/TWIST1 signaling pathway. Overall, silencing of hsa_circ_0001681 significantly suppressed TC progression through inhibiting EMT via acting as a miR-942-5p sponge to facilitate the expression of TWIST1. Our data provided a reliable evidence for hsa_circ_0001681 is a potential treatment target in TC.

ITGA6 and RPSA synergistically promote pancreatic cancer invasion and metastasis via PI3K and MAPK signaling pathways.

Pancreatic cancer is one of the most malignant tumors. Invasion and metastasis can occur in the early stage of pancreatic cancer, contributing to the poor prognosis. Accordingly, in this study, we evaluated the molecular mechanisms underlying invasion and metastasis. Using mass spectrometry, we found that Integrin alpha 6 (ITGA6) was more highly expressed in a highly invasive pancreatic cancer cell line (PC-1.0) than in a less invasive cell line (PC-1). Through in vitro and in vivo experiments, we observed significant decreases in invasion and metastasis in pancreatic cancer cells after inhibiting ITGA6. Based on data in TCGA, high ITGA6 expression significantly predicted poor prognosis. By using Co-IP combined mass spectrometry, we found that ribosomal protein SA (RPSA), which was also highly expressed in PC-1.0, interacted with ITGA6. Similar to ITGA6, high RPSA expression promoted invasion and metastasis and indicated poor prognosis. Interestingly, although ITGA6 and RPSA interacted, they did not mutually regulate each other. ITGA6 and RPSA affected invasion and metastasis via the PI3K and MAPK signaling pathways, respectively. Inhibiting ITGA6 significantly reduced the expression of p-AKT, while inhibiting RPSA led to the downregulation of p-ERK1/2. Compared with the inhibition of ITGA6 or RPSA alone, the downregulation of both ITGA6 and RPSA weakened invasion and metastasis to a greater extent and led to the simultaneous downregulation of p-AKT and p-ERK1/2. Our research indicates that the development of drugs targeting both ITGA6 and RPSA may be an effective strategy for the treatment of pancreatic cancer.

Betulinic acid induces apoptosis and suppresses metastasis in hepatocellular carcinoma cell lines in vitro and in vivo.

Hepatocellular carcinoma (HCC) is a high incidence and mortality malignant tumour globally. Betulinic acid (BA) is a pentacyclic triterpenoid with potential pro-apoptotic activities which widely found in many plants. In this study, we determined the effects of BA on proliferation, apoptosis, invasion, and metastasis in HCC cell lines and on tumour growth and pulmonary metastasis in mice. The results suggested that BA could inhibit cell viability and proliferation of HCC cell lines including HepG2, LM3, and MHCC97H. In addition, BA induced apoptosis of HepG2 cells characterised condensed nuclei and nuclear fragmentation. Moreover, western blot analysis showed that BA-induced apoptosis associated with increasing of pro-apoptotic protein Bax and cleaved caspase-3 and decreasing of anti-apoptotic protein Bcl-2. Meanwhile, BA also reduced the reactive oxygen species (ROS) level. Furthermore, BA also significantly inhibited HCC growth in vivo and blocked pulmonary metastasis of HCC by regulating the metastasis-related proteins including MMP-2, MMP-9, and TIMP2 without obvious toxicity. In all, the present study suggested that BA might be a promising anti-HCC drug candidate by inhibiting proliferation, inducing apoptosis, and blocking metastasis.

A novel scoring system associating with preoperative platelet/lymphocyte and clinicopathologic features to predict lymph node metastasis in early gastric cancer.

BACKGROUND: Precise determination of the lymph node status is critical for determining appropriate treatment for early gastric cancer (EGC). This study attempted to establish a simple, effective risk scoring system to predict lymph node metastasis (LNM) in EGC by investigating the relationship between platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) and EGC LNM. MATERIALS AND METHODS: We retrospectively reviewed 312 operable patients with EGC. The clinical utility of PLR and NLR was tested by receiver operating characteristic curves. The scoring system was developed using independent risk factors. Finally, 89 EGC patients were collected from prospective database to validate the scoring system's accuracy. RESULTS: The optimal PLR and NLR cut-off values were 106 and 2.97, respectively. High NLR (P = 0.009) and PLR (P = 0.007) values were associated with LNM of EGC in univariate analyses, although only high PLR (P = 0.025) was an independent risk factor in multivariate analyses, together with age (P = 0.009), differentiation (P = 0.017), invasive depth (P < 0.001), and tumor size (P = 0.003). The scoring system's accuracy for retrospective and prospective data was 0.781 (95% confidence interval: 0.721-0.841) and 0.817 (95% confidence interval 0.714-0.920), respectively. CONCLUSIONS: Preoperative PLR and NLR correlate with EGC LNM. Our scoring system is reliable, accurate, and effective in predicting LNM in EGC patients.

Association between Genetic Polymorphisms in DEFB1 and Susceptibility to Digestive Diseases.

BACKGROUND: Aberrant expression of defensins is implicated in the pathogenesis of digestive diseases. However, the contribution of specific defensins and the influence of their genetic polymorphisms on the progression of digestive diseases remain controversial. In the present meta-analysis, we investigated the association between DEFB1 SNPs and the susceptibility to digestive diseases. MATERIAL AND METHODS: Case-control studies that reported the correlation between DEFB1 SNPs and the susceptibility to digestive diseases were identified through electronic databases searches, and high-quality studies that satisfied our inclusion criteria were selected for this meta-analysis. Statistical analyses were performed utilizing STATA software version 12.0. RESULTS: The present meta-analysis revealed that patients with digestive diseases exhibited higher frequencies of the DEFB1 genetic variants rs11362G>A, rs1800972C>G, and rs1799946G>A compared to healthy controls under the allele model. Subgroup analysis based on country showed that the rs1800972C>G variant under allele model and rs1799946G>A are associated with the susceptibility to digestive diseases in Hungarian and Italian populations, respectively. Subgroup analysis based on disease type showed that: (1) rs11362G>A variant was strongly associated with severe acute pancreatitis (SAP) and chronic gastritis, (2) frequency of rs1800972C>G variant was higher in SAP subgroup, and (3) frequency of rs1799946G>A variant was positively associated with the susceptibility to Crohn's disease (CD) under the allele model and with SAP. CONCLUSIONS: Our meta-analysis provides evidence that DEFB1 genetic polymorphisms rs11362G>A, rs1800972C>G and rs1799946G>A are important contributing factors to the development of digestive diseases.

Correlations of common polymorphism of EVI-1 gene targeted by miRNA-206/133b with the pathogenesis of breast cancer.

The aim of this study was to identify the correlations of a common polymorphism (rs6774494 A > G) in the EVI-1 gene targeted by micro-RNA (miRNA)-206/133b with the pathogenesis of breast cancer (BC). A total of 196 unrelated ethnic Han Chinese women diagnosed with primary BC were consecutively recruited and 200 healthy controls were randomly selected from the same population-based cohort. Direct PCR sequencing assay was used to detection of rs6774494 A > G polymorphism in the EVI-1 gene. Real-time quantitative PCR (RT-PCR) analysis was performed to verify the alterations of the EVI1 messenger RNA (mRNA) levels. Kaplan-Meier analysis was used to investigate and to estimate the survival outcomes for each endpoint. All statistical analyses were performed with SPSS software (version 18.0, SPSS, Chicago, IL). Our results demonstrated that the carriers of EVI-1 AG genotype were more likely to develop BC when compared with the EVI-1 GG genotype (P = 0.034, OR = 1.26, 95% CI = 1.02 ∼ 1.57). In addition, it was found that patients with the G (AG + GG) allele of EVI-1 genetic variants were associated with higher risk of BC compared with the EVI-1 AA genotype (OR = 1.26, 95% CI = 1.02 ∼ 1.54, P = 0.028). The results of a subgroup analysis stratified by menopause revealed that in female post-menopause subgroup patients with the EVI-1 G allele were correlated with a higher risk of BC than those with the EVI-1 AA genotype (OR = 1.31, 95% CI = 1.00 ∼ 1.72, P = 0.054). Kaplan-Meier analyses suggested that carriers of the G allele (AG + GG) were associated with poorer overall survival (OS) and progression-free survival (PFS) compared with those with AA genotype (OS P = 0.042; PFS P = 0.036, respectively). The correlation analysis showed that EVI-1 mRNA levels were negatively associated with miRNA-206/133b levels in the carriers of the G allele (AG + GG) (r = -1.274, P < 0.05). Our findings provide evidence that the EVI-1 rs6774494 G > A polymorphism targeted by miRNA-206/133b may contribute to the pathogenesis of BC.

Glycyrrhetinic acid exhibits strong inhibitory effects towards UDP-glucuronosyltransferase (UGT) 1A3 and 2B7.

The aim of the present study is to evaluate the inhibitory effects of liver UDP-glucuronosyltransferases (UGTs) by glycyrrhizic acid and glycyrrhetinic acid, which are the bioactive ingredients isolated from licorice. The results showed that glycyrrhetinic acid exhibited stronger inhibition towards all the tested UGT isoforms, indicating that the deglycosylation process played an important role in the inhibitory potential towards UGT isoforms. Furthermore, the inhibition kinetic type and parameters were determined for the inhibition of glycyrrhetinic acid towards UGT1A3 and UGT2B7. Data fitting using Dixon and Lineweaver-Burk plots demonstrated that the inhibition of UGT1A3 and UGT2B7 by glycyrrhetinic acid was best fit to competitive and noncompetitive type, respectively. The second plot using the slopes from Lineweaver-Burk plots versus glycyrrhetinic acid concentrations was employed to calculate the inhibition kinetic parameters (K(i)), and the values were calculated to be 0.2 and 1.7 µM for UGT1A3 and UGT2B7, respectively. All these results remind us the possibility of UGT inhibition-based herb-drug interaction. However, the explanation of these in vitro parameters should be paid more caution due to complicated factors, including the probe substrate-dependent UGT inhibition behaviour, environmental factors affecting the abundance of herbs' ingredients, and individual difference of pharmacokinetic factors.

Erratum: IRS-1 regulates proliferation, invasion and metastasis of pancreatic cancer cells through MAPK and PI3K signaling pathways.

[This corrects the article on p. 5185 in vol. 11, PMID: 31949598.].

A new rapid and sensitive method for detecting chicken infectious anemia virus.

Since the chicken infectious anemia virus (CIAV) was discovered in 1979, which has been reported as an economically significant and immunosuppressive poultry disease in the world. A novel clinical detection method for the prevention and control of CIAV in the poultry sector is urgently needed. Here, we established a real-time recombinase-aided amplification assay (RAA) for CIAV on-site with a rapid, highly sensitive, strongly specific, low-cost, and simple operational molecular diagnosis detection method. The primers and probe were developed using the CIAV VP2 gene sequence, which has a 117-bp specific band. This assay, which could be carried out at 41°C and completed in 30 min without cross-reactivity with other viruses, had the lowest detection limit of 10 copies of CIAV DNA molecules per reaction. Furthermore, the kappa value of this assay was 0.947, the sensitivity was 93.33%, and the specificity was 100% when compared to the real-time quantitative polymerase chain reaction assay (real-time qPCR). These results indicate that using a real-time RAA assay to detect CIAV on-site could be beneficial. In the future, the real-time RAA test may be a regular assay for the prevention and control of CIAV, as well as help the reduction of economic losses in the poultry business.

Pectin Oligosaccharides Enhance α2,6-Sialylation Modification that Promotes Apoptosis of Bladder Cancer Cells by Targeting the Hedgehog Pathway.

Although pectin oligosaccharide (POS) can inhibit the growth and proliferation of gastric, colon, prostate, breast, melanoma, and leukemia cells, its effect on bladder cancer remains unknown. Therefore, screening and identification of factors associated with the sensitivity of bladder cancer to drugs and elucidation of their molecular mechanisms will help provide a theoretical basis for establishing postoperative systemic chemotherapy for patients with bladder cancer. We showed that POS promoted the apoptosis of bladder cancer cells, and this finding was consistent with enhanced α2,6-sialylation post-modification. Moreover, POS activated the Hedgehog pathway, the inhibition of which regulated the tumorigenicity of bladder cancer cells in vivo. These findings were consistent with our results in vitro. We conclude that POS promotes the apoptosis of bladder cancer and offers new insights and evidence for the development of individualized treatment strategies. Schema of molecular events underlying POS-induced inhibition of bladder cancer cell proliferation.

POU2F1 induces the immune escape in lung cancer by up-regulating PD-L1.

PURPOSE: The aim was to research the POU2F1 related genes and mechanism during the progress of immune escape of lung cancer. METHODS: Lung cancer cell lines (H1993, HCC827, A549, H2228, H3122 and H1975) and Human normal lung epithelial cell line (BEAS-2B) were involved in this study. Overexpression or knockdown of POU2F1 was processed in lung cancer cells. POU2F1, PD-L1 and CRK expression in cells were detected by WB and RT-PCR. Flow cytometry and immunofluorescence was used to detect PD-L1 expression on the cell surface. Luciferase reporter detected the promoter activity of CRK. C57BL/6 mice models with knocked down of of POU2F1 were constructed. After tumor formation, anti-PD-1 was administered to detect tumor suppressing ability. IHC assay showed the number of intratumoral CD3+, CD8+, GranzB+ T cells. RESULTS: POU2F1 and PD-L1 were positively correlated in lung cancer cell lines. Overexpression of POU2F1 promoted the expression level of PD-L1 in lung cancer cells. POU2F1 transcription activated the expression of CRK, and further promoted the expression of PD-L1. Knockdown of POU2F1 promoted the efficacy of Anti-PD-1. In addition, tumor growth ability decreased after POU2F1 was knocked down. Cytotoxic effector cytokines levels, tumor suppressive chemokines and interleukin increased, while IL17a level decreased when POU2F1 was knocked down. CONCLUSION: POU2F1 activates the expression of CRK, further promotes the expression of PD-L1, and finally improves the immune escape in lung cancer.

Effect of A-scan rate and interscan interval on optical coherence angiography.

Optical coherence tomography angiography (OCTA) can provide rapid, volumetric, and noninvasive imaging of tissue microvasculature without the requirement of exogenous contrast agents. To investigate how A-scan rate and interscan time affected the contrast and dynamic range of OCTA, we developed a 1.06-µm swept-source OCT system enabling 100-kHz or 200-kHz OCT using two light sources. After system settings were carefully adjusted, almost the same detection sensitivity was achieved between the 100-kHz and 200-kHz modalities. OCTA of ear skin was performed on five mice. We used the variable interscan time analysis algorithm (VISTA) and the designated scanning protocol with OCTA images reconstructed through the correlation mapping method. With a relatively long interscan time (e.g., 12.5 ms vs. 6.25 ms for 200-kHz OCT), OCTA can identify more intricate microvascular networks. OCTA image sets with the same interscan time (e.g., 12.5 ms) were compared. OCTA images acquired with a 100-kHz A-scan rate showed finer microvasculature than did other imaging modalities. We performed quantitative analysis on the contrast from OCTA images reconstructed with different A-scan rates and interscan time intervals in terms of vessel area, total vessel length, and junction density.

Quantitative spectroscopic comparison of the optical properties of mouse cochlea microstructures using optical coherence tomography at 1.06†µm and 1.3†µm wavelengths.

Currently, the cochlear implantation procedure mainly relies on using a hand lens or surgical microscope, where the success rate and surgery time strongly depend on the surgeon's experience. Therefore, a real-time image guidance tool may facilitate the implantation procedure. In this study, we performed a systematic and quantitative analysis on the optical characterization of ex vivo mouse cochlear samples using two swept-source optical coherence tomography (OCT) systems operating at the 1.06-µm and 1.3-µm wavelengths. The analysis results demonstrated that the 1.06-µm OCT imaging system performed better than the 1.3-µm OCT imaging system in terms of the image contrast between the cochlear conduits and the neighboring cochlear bony wall structure. However, the 1.3-µm OCT imaging system allowed for greater imaging depth of the cochlear samples because of decreased tissue scattering. In addition, we have investigated the feasibility of identifying the electrode of the cochlear implant within the ex vivo cochlear sample with the 1.06-µm OCT imaging. The study results demonstrated the potential of developing an image guidance tool for the cochlea implantation procedure as well as other otorhinolaryngology applications.

Role of exosomal microRNA-125b-5p in conferring the metastatic phenotype among pancreatic cancer cells with different potential of metastasis.

AIMS: To explore the pro-metastatic role of exosomes derived from highly invasive pancreatic cancer cell and the associated aberrant expression of exosomal microRNAs (miRNAs). MAIN METHODS: Weakly invasive PC-1 cells were treated with exosomes of highly invasive PC-1.0 cells to determine the pro-metastatic effect of PC-1.0 derived exosomes. The exosomal miRNA profile was further investigated using high-throughput sequencing. The level of miR-125b-5p in highly and weakly invasive pancreatic cancer cells was further determined. Pancreatic cancer cells transfected with miR-125b-5p mimic and inhibitor were used to explore the effect of miR-125b-5p on migration, invasion and epithelial-to-mesenchymal transition (EMT). Treatment with PC-1.0 derived exosome and Western blot assay were performed to validate STARD13 as a target of exosomal miR-125b-5p in pancreatic cancer. KEY FINDINGS: PC-1.0 derived exosomes promoted the migration and invasion of weakly invasive PC-1 cells. miRNA sequencing revealed 62 miRNAs upregulated in PC-1.0 derived exosomes. miR-125b-5p most significantly promoted migration and invasion and was associated with metastasis in pancreatic cancer. Further, miR-125b-5p was upregulated in highly invasive pancreatic cancer cells and increased migration, invasion, and EMT. Moreover, its upregulation was associated with activation of MEK2/ERK2 signaling. The tumor suppressor STARD13 was directly targeted by miR-125b-5p in pancreatic cancer, which was associated with good prognosis and was suppressed by exosomes derived from highly invasive cancer cells. SIGNIFICANCE: This study explored the pro-metastatic role of exosomes derived from highly invasive pancreatic cancer cells and the associated aberrant expression of exosomal miRNAs, which may help to elucidate the metastatic mechanism of pancreatic cancer.

Integrin beta 4 (ITGB4) and its tyrosine-1510 phosphorylation promote pancreatic tumorigenesis and regulate the MEK1-ERK1/2 signaling pathway.

Pancreatic cancer is the fourth leading cause of cancer death, with a 5-year survival rate of only 1-4%. Integrin-mediated cell adhesion is critical for the initiation, progression, and metastasis of cancer. In this study we investigated the role of integrin b4 (ITGB4) and its phosphorylation at tyrosine Y1510 (p-ITGB4-Y1510) in the tumorigenesis of pancreatic cancer. We analyzed the expression of ITGB4 and p-ITGB4-Y1510 in pancreatic cancer tissue and cell lines using immunohistochemistry, Western blot, or semi-quantitative reverse transcription PCR. ITGB4 and p-ITGB4-Y1510 were highly expressed in pancreatic cancer (n = 176) compared with normal pancreatic tissue (n = 171). High p-ITGB4-Y1510 expression correlated with local invasion and distant metastasis of pancreatic cancer, and high ITGB4 was significantly associated with poor survival of patients. Inhibition of ITGB4 by siRNA significantly reduced migration and invasion of PC-1.0 and AsPC-1 cells. Overexpression of the mutant ITGB4-Y1510A (a mutation of tyrosine to alanine at 1510 position) in PC-1.0 and AsPC-1 cells not only blocked the ITGB4 phosphorylation at Y1510 but also suppressed the expression of ITGB4 (p < 0.05 vs. wild-type ITGB4). The transfection of PC-1.0 and AsPC-1 cells with ITGB4-Y1510A significantly decreased the level of p-mitogen-activated protein kinase kinase (MEK)1 (T292) and p-extracellular signal-regulated kinase (ERK)1/2 but did not affect the level of p-MEK1 (T386) and p-MEK2 (T394). Overall, our study showed that ITGB4 and its phosphorylated form promote cell migration and invasion in pancreatic cancer and that p-ITGB4-Y1510 regulates the downstream MEK1-ERK1/2 signaling cascades. Targeting ITGB4 or its phosphorylation at Y1510 may be a novel therapeutic option for pancreatic cancer.

Guajadial reverses multidrug resistance by inhibiting ABC transporter expression and suppressing the PI3K/Akt pathway in drug-resistant breast cancer cells.

Multidrug resistance remains a major challenge in the chemotherapy of breast cancer. Guajadial, a natural meroterpenoid, has been found to possess anti-tumor activity. However, the role of guajadial in drug resistance has not been investigated. The aim of this study was to evaluate the effect of guajadial on drug resistance in drug-resistant breast cancer cells. Cell viability was measured by MTT assay, and the IC50 values were calculated. The expression of ATP-binding cassette (ABC) transporters including P-glycoprotein (P-gp) and the breast cancer resistance protein (BCRP) was detected by qRT-PCR and western blot. The expression of Akt, p-Akt, p70S6K, and p-p70S6K was determined by western blot. We found that guajadial significantly inhibited cell viability of parental non-resistant cell line MCF-7, adriamycin (ADR)-resistant cell line MCF-7/ADR, and paclitaxel (PTX)-resistant cell line MCF-7/PTX in a dose-dependent manner. Guajadial enhanced ADR and PTX sensitivity of MCF-7/ADR and MCF-7/PTX cells, and inhibited the expression of P-gp and BCRP. Guajadial treatment resulted in an inactivation of PI3K/Akt pathway in drug-resistant MCF-7 cells. In conclusion, guajadial acted as an inhibitor of drug resistance, which might be mediated by the inhibition of ABC transporter expression and PI3K/Akt pathway in drug-resistant breast cancer cells. These findings suggested that guajadial treatment might be a new approach to overcome the drug resistance in the chemotherapy of breast cancer.

IRS-1 regulates proliferation, invasion and metastasis of pancreatic cancer cells through MAPK and PI3K signaling pathways.

PC is one of the deadliest cancers, with unexpectedly high mortality. The main reason for poor prognosis is the high likelihood of invasion and metastasis of pancreatic cancer cells. Mechanism of exceptional protein phosphorylation that regulates cell invasion and metastasis in pancreatic cancer remain unclear. In our previous studies, we used high-throughput phosphorylation array to test two pancreatic cancer cell lines (PC-1 cells with a low potential, and PC-1.0 cells with a high potential, for invasion and metastasis). We noted that a total of 57 proteinsrevealed a differential expression (fold change 2.0). We supposed that insulin receptor substrate-1 (IRS-1) may play a significant role in pancreatic cancer invasion and metastasis. In this study, similar phosphorylation and protein expression levels together with morphological and functional characteristics were observed in PC-1.0 hamster pancreatic cancer cells and Aspc-1 human pancreatic cancer cells (similar to PC-1.0 in features) transiently transfected with IRS-1 siRNA. Our results indicated that proliferation, invasion and metastasis were reduced in both hamster and human pancreatic cancer cells. IRS-1 was found to regulate the target proteins involved in MAPK and PI3K signaling pathways, which include MEK1, MEK2 and AKT, at the protein and phosphorylation level. Low expression of IRS-1 in pancreatic cancer cells inhibited cell proliferation by targeting MEK1 and AKT, while inhibiting invasion and metastasis by targeting MEK2. Moreover, our results demonstrate that IRS-1 protein and phosphorylation expression levels are negatively controlled by LAR (protein tyrosine phosphatase, receptor type, F). LAR inhibited proliferation, invasion and metastasis of pancreatic cancer cells via a direct decrease of IRS-1 protein and phosphorylation expression levels. In summary, we demonstrate that IRS-1 regulates proliferation, invasion and metastasis of pancreatic cancer cells, and provides a new biomarker in an effort to develop novel therapeutic drug targets for pancreatic cancer treatment.