MiR-125b regulates the proliferation and metastasis of triple negative breast cancer cells via the Wnt/ß-catenin pathway and EMT.

BACKGROUND/AIM: MiR-125b plays an important role in breast cancer. The current study was to explore the expression and function of miR-125b in triple negative breast cancer cells. MATERIALS AND METHODS: The expression of miR-125b in human TNBC samples and cell lines were examined by qRT-PCR. MTT, scratch assays and transwell assays were utilized to observe the proliferation, migration and invasion ability. MiR-125b's target gene and downstream signaling pathways were investigated by Luciferase Reporter Assays, qRT-PCR, immunofluorescence assays and western bolt. RESULTS: MiR-125b was highly expressed in human TNBC tissues and cell lines. Inhibiting miR-125b expression suppressed the proliferation, cell migration and invasion. The three-prime untranslated region (3´-UTR) of adenomatous polyposis coli (APC) mRNA contains miR-125b binding sites, and inhibiting miR-125b expression suppressed the activity of the intracellular Wnt/ß-catenin pathways and EMT. CONCLUSION: Inhibiting miR-125b regulates the Wnt/ß-catenin pathway and EMT to suppress the proliferation and migration of MDA-MB-468 TNBC cells.

An orally administered DNA vaccine targeting vascular endothelial growth factor receptor-3 inhibits lung carcinoma growth.

Lung cancer is the leading cause of mortality and 5-year survival rate is very low worldwide. Recent studies show that vascular endothelial growth factor receptor-3 (VEGFR-3) signaling pathway contributes to lung cancer progression. So we hypothesize that an oral DNA vaccine that targets VEGFR-3 carried by attenuated Salmonella enterica serovar typhimurium strain SL3261 has impacts on lung cancer progression. In this study, the oral VEGFR-3-based vaccine-immunized mice showed appreciable inhibition of tumor growth and tumor lymphatic microvessels in lung cancer mice model. Moreover, the oral VEGFR-3-based vaccine-immunized mice showed remarkable increases in both VEGFR-3-specific antibody levels and cytotoxic activity. Furthermore, the oral VEGFR-3-based vaccine-immunized mice showed a significant increase in the levels of T helper type 1 (Th1) cell intracellular cytokine expression (IL-2, IFN-γ, and TNF-α). After inoculation with murine Lewis lung carcinoma (LLC) cells, CD4(+) or CD8(+) T cell numbers obviously declined in control groups whereas high levels were maintained in the oral VEGFR-3-based vaccine group. These results demonstrated that the oral VEGFR-3-based vaccine could induce specific humoral and cellular immune responses and then significantly inhibit lung carcinoma growth via suppressing lymphangiogenesis.

Acquired resistance to HSP90 inhibitor 17-AAG and increased metastatic potential are associated with MUC1 expression in colon carcinoma cells.

Heat shock protein 90 (HSP90) is a molecular chaperone required for the stability and function of many proteins. The chaperoning of oncoproteins by HSP90 enhances the survival, growth, and invasive potential of cancer cells. HSP90 inhibitors are promising new anticancer agents, in which the benzoquinone ansamycin 17-allylamino-17-demethoxygeldanamycin (17-AAG) is currently in clinical evaluation. However, the implications of acquired resistance to this class of drug remain largely unexplored. In the present study, we have generated isogenic human colon cancer cell lines that are resistant to 17-AAG by continued culturing in the compound. Cross-resistance was found with another HSP90 inhibitor 17-dimethylaminoethylamino-17-demethoxygeldanamycin. The resistant cells showed obvious morphology changes with a metastatic phenotype and significant increases in migration and adhesion to collagens. Western blotting analysis of epithelial-mesenchymal transition molecular markers found that expression of E-cadherin downregulated, whereas expression of N-cadherin and ß-catenin upregulated in the resistant cells. Mucin 1 (MUC1) has been reported to mediate metastasis as well as chemical resistance in many cancers. Here, we found that MUC1 expression was significantly elevated in the acquired drug resistance cells. 17-AAG treatment could decrease MUC1 more in parental cells than in acquired 17-AAG-resistant cells. Further study found that knockdown of MUC1 expression by small interfering RNA could obviously re-sensitize the resistant cells to 17-AAG treatment, and decrease the cell migration and adhesion. These were coupled with a downregulation in N-cadherin and ß-catenin. The results indicate that HSP90 inhibitor therapies in colon carcinomas could generate resistance and increase metastatic potential that might mediated by upregulation of MUC1 expression. Findings from this study further our understanding of the potential clinical effects of HSP90-directed therapies in colon carcinomas.

Development of biodegradable polycaprolactone film as an internal fixation material to enhance tendon repair: an in vitro study.

BACKGROUND: Current tendon repair techniques do not provide sufficient tensile strength at the repair site, and thus early active motion rehabilitation after tendon repair is discouraged. To enhance the post-operative tensile strength, we proposed and tested an internal fixation technique using a polycaprolactone (PCL) biofilm. PCL was chosen for its good biocompatibility, excellent mechanical strength, and an appropriate degradation time scale. METHODS: PCL biofilms were prepared by a modified melt-molding/leaching technique, and the physical and mechanical properties and in vitro degradation rate were assessed. The pore size distribution of the biofilm and the paratenon of native tendons were observed using scanning electron microscopy. Next, we determined whether this biofilm could enhance the tensile strength of repaired tendons. We performed tensile tests on rabbit Achilles tendons that were first lacerated and then repaired: 1) using modified Kessler suture combined with running peripheral suture ('control' group), or 2) using biofilm to wrap the tendon and then fixation with sutures ('biofilm' group). The influence of different repair techniques on tendon tensile strength was evaluated by mechanical testing. RESULTS: The novel biofilm had supple texture and a smooth surface. The mean thickness of the biofilm was 0.25 mm. The mean porosity of the biofilm was 45.3%. The paratenon of the rabbit Achilles tendon had pores with diameters ranging from 1 to 9 µm, which were similar to the 4-12 µm diameter pores in the biofilm cross-section. The weight loss of the biofilms at 4 weeks was only 0.07%. The molecular weight of PCL biofilms did not change after immersion in phosphate buffered saline for 4 weeks. The failure loads of the biofilm were similar before (48 ± 9 N) and after immersion (47 ± 7 N, P > 0.1). The biofilm group had ~70% higher mean failure loads and 93% higher stiffness compared with the control group. CONCLUSIONS: We proposed and tested an internal fixation technique using a PCL biofilm to enhance tendon repair. Internal fixation with the biofilm followed by standard suturing can significantly increase the tensile strength of tendon repair sites. This technique has the potential to allow active motion rehabilitation during the early post-operative period.

Detrimental effect of electromagnetic pulse exposure on permeability of in vitro blood-brain-barrier model.

OBJECTIVE: To study the effect of electromagnetic pulse (EMP) exposure on permeability of in vitro blood-brain-barrier (BBB) model. METHODS: An in vitro BBB model, established by co-culturing brain microvascular endothelial cells (BMVEC) and astroglial cells (AC) isolated from rat brain, was exposed to EMP at 100 kV/m and 400 kV/m, respectively. Permeability of the model was assayed by measuring the transendothelial electrical resistance (TEER) and the horseradish peroxidase (HRP) transmission at different time points. Levels of BBB tight junction-related proteins were measured at 0, 1, 2, 4, 8, 12, 16, 20, 24 h after EMP exposure by Western blotting. RESULTS: The TEER level was lower in BBB model group than in control group at 12 h after EMP, exposure which returned to its normal level at 24 h. The 24 h recovery process was triphasic and biphasic respectively after EMP exposure at 100 kV/m and 400 kV/m. Following exposure to 400 kV/m EMP, the HRP permeability increased at 1-12 h and returned to its normal level at 24 h. Western blotting showed that the claudin-5 and ZO-1 protein levels were changed after EMP exposure. CONCLUSION: EMP exposure at 100 kV/m and 400 kV/m can increase the permeability of in vitro BBB model and BBB tight junction-related proteins such as ZO-1 and claudin-5 may change EMP-induced BBB permeability.

[Expression of transcription factor SOX4 and its clinical significance in female lung cancer patients in Xuanwei area, Yunnan Province].

OBJECTIVE: To investigate the expression of transcription factor SOX4 in lung cancer tissues of female patients in Xuanwei area, Yunnan Province, and explore its correlation with clinicopathological characteristics and prognosis of the female patients. METHODS: Real-time PCR was applied on lung cancer specimens and their corresponding normal lung tissues from 96 female cases of Xuanwei area to assess the expression of SOX4 mRNA. Immunohistochemical staining was performed to investigate the SOX4 protein expression, and further to elucidate its correlation with clinicopathological characteristics and prognosis. RESULTS: The expression level of SOX4 mRNA in the cancer tissues (2.53 ± 1.65) was significantly higher than that of matched normal tissues (1.43 ± 1.14, P = 0.003). Immunohistochemical staining showed that there were 53.1% (51/96) positive expression of SOX4 protein in the cancer tissue and only 26.0% (25/96) in matched normal tissue (P < 0.001). The expression of SOX4 protein had a significant correlation with clinical stage, lymph node metastasis and differentiation of tumor (P < 0.05). The survival analysis by Kaplan-Meier method showed that patients with positive expression of SOX4 protein, lymph node metastasis and advanced tumor stage had a significantly shorter median survival time (P < 0.05). Cox regression survival analysis showed that pathological grade was a significant independent factor affecting prognosis. CONCLUSIONS: The expressions of SOX4 mRNA and protein are significantly up-regulated in Xuanwei female lung cancer patients. Patients with positive SOX4 expression have a shorter median survival time. SOX4 protein expression level combined with pathological grade can be used as a prognostic indicator of female lung cancer patients in Xuanwei area, Yunnan Province.

[Review on the Long-term and Short-term Effects of Biochar Addition on Soil Greenhouse Gas Emissions].

Increasing concentrations of greenhouse gases in the atmosphere caused by human activities are the main cause of climate warming. Global warming is a severe challenge confronted by human society today. Reducing greenhouse gas emissions and increasing carbon sinks are the keys to addressing climate warming. Biochar addition is considered to be a promising way to reduce greenhouse gas emissions and increase carbon sinks, due to its unique physical, chemical, and biological properties. Therefore, it is of great significance to study the effects of biochar on soil greenhouse gas emissions to mitigate the greenhouse effect and achieve "carbon neutrality." The long-term and short-term effects of biochar on soil greenhouse gas emissions and their influencing mechanism were reviewed. It was found that the effects of biochar on soil greenhouse gas emissions varied with the types of biochar feedstock, pyrolysis temperature, application ratio, and soil and vegetable types. In addition, due to the different aging times and modes and cultivation methods, the mitigation effect of aged biochar on soil greenhouse gas could be enhanced or weakened or even disappeared. Further, based on the deficiencies of the previous research, the direction and focus of future research on the effects of biochar on soil greenhouse gas emissions were analyzed and prospected. It was proposed to strengthen simultaneous research on the effects of biochar on CO2, N2O, and CH4 emissions; reducing greenhouse gas emissions and carbon sequestration; different aging modes and cultivation methods of biochar; and revealing the influencing mechanism at the process level, through exploring the effects of biochar on soil carbon and nitrogen dynamics and tracing the source of greenhouse gases using 13C and 15N tracer technology.

USP1 promotes cholangiocarcinoma progression by deubiquitinating PARP1 to prevent its proteasomal degradation.

Despite its involvement in various cancers, the function of the deubiquitinase USP1 (ubiquitin-specific protease 1) is unexplored in cholangiocarcinoma (CCA). In this study, we provide evidence that USP1 promotes CCA progression through the stabilization of Poly (ADP-ribose) polymerase 1 (PARP1), consistent with the observation that both USP1 and PARP1 are upregulated in human CCA. Proteomics and ubiquitylome analysis of USP1-overexpressing CCA cells nominated PARP1 as a top USP1 substrate. Indeed, their direct interaction was validated by a series of immunofluorescence, co-immunoprecipitation (CO-IP), and GST pull-down assays, and their interaction regions were identified using deletion mutants. Mechanistically, USP1 removes the ubiquitin chain at K197 of PARP1 to prevent its proteasomal degradation, with the consequent PARP1 stabilization being necessary and sufficient to promote the growth and metastasis of CCA in vitro and in vivo. Additionally, we identified the acetyltransferase GCN5 as acetylating USP1 at K130, enhancing the affinity between USP1 and PARP1 and further increasing PARP1 protein stabilization. Finally, both USP1 and PARP1 are significantly associated with poor survival in CCA patients. These findings describe PARP1 as a novel deubiquitination target of USP1 and a potential therapeutic target for CCA.

[The pathological changes and apoptosis of spleen lymphocytes in mice induced by electromagnetic pulses].

OBJECTIVE: To study the effects of electromagnetic pulses (EMP) on pathological changes and apoptosis of spleen lymphocytes in mice. METHODS: The male BALB/c mice (18 ∼ 22 g) were sham-exposed or exposed to EMP at 200 kV/m for 400 pulses a day for 7 days. On the 1st, 3rd, 7th, 14th 28th days after exposure the mice were killed. The weight of mice, the pathological change and the weight of mouse spleens were observed, the spleen indexes were calculated. The lymphocytes extracted from spleens were counted. The apoptosis and cell cycle of the lymphocyte were detected by flow cytometry, and the migration of the lymphocyte was measured by transwell assay. RESULTS: No pathological changes were found on the first day after exposure. However, the expanded sinusoid and the changed structure of spleen corpuscle on the 3rd day after exposure were observed. There was no difference of spleen indexes between the sham group and the exposure group on the 1st and 14th day after exposure. On the 3rd and 7th days after exposure, the spleen indexes of exposure group were significantly higher than those of sham-exposure group (P < 0.05). On the 28th day after exposure, the spleen indexes of exposure group was significantly lower than those of sham-exposure group (P < 0.05). The number of spleen lymphocytes on the 3rd and 7th days after exposure in exposure group increased significantly, compared with sham-exposure group (P < 0.05). But there were no differences of apoptotic cells and cellular cycle between the exposure group and sham-exposure group (P > 0.05). The ability of migration of the exposure group was significantly higher than that of sham-exposure group (P < 0.05). than the sham group (P < 0.05). CONCLUSION: The spleen of the male mouse is one of the target organs of EMP. After exposure to EMP, the number of spleen lymphocytes increased. But there were no differences of cell apoptotic cells and cell cycle between the sham group and the exposure group, due to the enhanced migration of lymphocytes induced by EMP.

Mutations and clinical significance of calcium voltage-gated channel subunit alpha 1E (CACNA1E) in non-small cell lung cancer.

CACNA1E is a gene encoding the ion-conducting α1 subunit of R-type voltage-dependent calcium channels, whose roles in tumorigenesis remain to be determined. We previously showed that CACNA1E was significantly mutated in patients with non-small cell lung cancer (NSCLC) who were long-term exposed to household air pollution, with a mutation rate of 19% (15 of 79 cases). Here we showed that CACNA1E was also mutated in 207 (12.8%) of the 1616 patients with NSCLC in The Cancer Genome Atlas (TCGA) datasets. At mRNA and protein levels, CACNA1E was elevated in tumor tissues compared to counterpart non-tumoral lung tissues in NSCLCs of the public datasets and our settings, and its expression level was inversely associated with clinical outcome of the patients. Overexpression of wild type (WT) or A275S or R249G mutant CACNA1E transcripts promoted NSCLC cell proliferation with activation of epidermal growth factor receptor (EGFR) signaling pathway, whereas knockdown of this gene exerted inhibitory effects on NSCLC cells in vitro and in vivo. CACNA1E increased current density and Ca2+ entrance, whereas calcium channel blockers inhibited NSCLC cell proliferation. These data indicate that CACNA1E is required for NSCLC cell proliferation, and blockade of this oncoprotein may have therapeutic potentials for this deadly disease.

Detection of cytokeratin 19, human mammaglobin, and carcinoembryonic antigen-positive circulating tumor cells by three-marker reverse transcription-PCR assay and its relation to clinical outcome in early breast cancer.

AIMS: To investigate the diagnostic, predictive, and prognostic value of the detection of circulating tumor cells (CTCs) using a three-marker (CK19, hMAM and CEA) RT-PCR assay in patients with early breast cancer. PATIENTS AND METHODS: Peripheral blood was obtained from 50 patients with early-stage breast cancer before any systemic adjuvant therapy and analyzed for the presence of CK-19, hMAM and CEA mRNA-positive CTCs using an RT-PCR assay. The specificity of the primers used was evaluated in 20 healthy individuals, 24 patients with benign breast disease, and 30 patients with metastatic breast cancer. The detection of CTCs was correlated with clinical outcome. RESULTS: The detection rate of three-marker-positive CTCs in the blood of patients with early breast cancer was 54.0%, significantly higher than in patients with benign breast disease and healthy blood donors (p=0.002 and p=0.000, respectively). The three-marker RT-PCR assay had 58.8% sensitivity in the parallel test and 100% specificity for CTC detection in the serial test, which was higher than the sensitivity and specificity of single-marker assays. For early breast cancer, correlation analysis between detection of three-marker-positive CTCs and clinicopathological characteristics indicated that detection of threemarker-positive CTCs was significantly correlated with elevated serum CEA levels (p=0.001). After three years of follow-up, 13 of the 27 patients with three-marker-positive CTCs in their blood had relapsed and detection of three-marker-positive CTCs was significantly associated with locoregional recurrence and/or distant metastasis (p=0.002). Detection of three-marker-positive CTCs in peripheral blood was an independent risk factor for reduced median relapse-free interval (p=0.000). CONCLUSION: The three-marker RT-PCR assay can enhance the sensitivity and specificity of CTC detection compared to singlemarker assay. Detection of three-marker-positive CTCs was associated with relapse and might have important predictive and prognostic implications in early breast cancer.

Orally administered DNA vaccine delivery by attenuated Salmonella typhimurium targeting fetal liver kinase 1 inhibits murine Lewis lung carcinoma growth and metastasis.

The vascular endothelial growth factor (VEGF) receptor 2 (VEGFR-2), also called fetal liver kinase 1 (FLK1) in mice and kinase insert domain receptor (KDR) in humans, is an endothelial cell specific receptor tyrosine kinase that mediates lung cancer angiogenesis. We hypothesized that an active immunotherapy approach targeting FLK1 may inhibit lung cancer growth and metastasis. To test this hypothesis, we evaluated whether immune responses to FLK1 could be elicited in mice by immunization with an orally administered DNA vaccine encoding the extracellular domain (ECD) of FLK1 (pcDNA3.1-FLK1(ECD)) carried by attenuated Salmonella typhimurium. We found that the vaccine was effective at protective antitumor immunity in Lewis lung carcinoma models in mice by breaking immune tolerance to FLK1 self-antigen. Both FLK1-specific humoral and cellular immune responses against endothelial cells can be induced in mice by immunization with pcDNA3.1-FLK1(ECD). Immunization with pcDNA3.1-FLK1(ECD) resulted in tumor suppression and prolonged survival in mice challenged with Lewis lung carcinomas cells. Experimental pulmonary metastases were strongly inhibited in pcDNA3.1-FLK1(ECD) immunized mice challenged with Lewis lung carcinoma cells. Thus, we conclude that the plasmid DNA vaccine encoding the extracellular domain of FLK1 could be an important component of FLK1 DNA vaccine to prevent lung carcinoma recurrence and metastasis after surgery.

High STRN Expression Promotes HCC Invasion and Migration but Not Cell Proliferation or Apoptosis through Facilitating Epithelial-Mesenchymal Transition.

A STRN-ALK fusion protein has been recently identified as a potential therapeutic target in multiple cancers; however, the role of STRN alone in regulating the biological function of hepatocellular carcinoma (HCC) remains unclear. In this study, we firstly detected an overexpression of STRN in HCC tissues compared to that in adjacent nontumour (ANT) tissues through IHC analysis, and the expression level of this protein was positively correlated with lymph node metastasis and TNM stage. In vitro, high expression of STRN was also confirmed in different HCC cell lines, and regulation of STRN expression in Huh7 cells did not significantly affect tumour cell proliferation or apoptosis but was positively correlated with tumour cell invasion and migration capacities. Moreover, both the knockdown and overexpression of STRN in Huh7 cells can lead to cell morphological changes that are accompanied with an alteration of epithelial-mesenchymal transition (EMT) molecular markers E-cadherin and Vimentin. Finally, STRN was further proved to be negatively related to E-cadherin expression but positively related to Vimentin expression in human HCC tissue samples. Taken together, STRN is upregulated in HCC and acts as a tumour promoter regulating cell invasion and migration through facilitating the EMT process.

Suppression of Musashi­2 by the small compound largazole exerts inhibitory effects on malignant cells.

RNA­binding protein Musashi­2 (MSI2) serves as a regulator of numerous pivotal biological processes associated with cancer initiation, development and resistance to treatment, and may represent a promising drug target. However, whether MSI2 inhibition is of value in antitumor treatment remains to be determined. The present study demonstrated that MSI2 was upregulated in non­small cell lung cancer (NSCLC) and was inversely associated with the clinical outcome of the patients. Molecular docking analysis demonstrated that the small compound largazole binds to and may be a potential inhibitor of MSI2. Largazole markedly decreased the protein and mRNA levels of MSI2 and suppressed its downstream mammalian target of rapamycin signaling pathway. Largazole also inhibited the proliferation and induced apoptosis of NSCLC and chronic myeloid leukemia (CML) cells (including bone marrow mononuclear cells harvested from CML patients). These results indicate that MSI2 is an emerging therapeutic target for NSCLC and CML, and the MSI2 inhibitor largazole may hold promise as a treatment for these malignancies.

Systematic identification of CDC34 that functions to stabilize EGFR and promote lung carcinogenesis.

BACKGROUND: How the oncoprotein epidermal growth factor receptor (EGFR) evades proteolytic degradation and accumulates in non-small cell lung cancer (NSCLC) remains unclear, and ubiquitin pathway genes (UPGs) that are critical to NSCLC needs to be systematically identified. METHODS: A total of 696 UPGs (including E1, E2, E3, and deubiquitinases) were silenced by small interfering RNA (siRNA) library in NSCLC cells, the candidates were verified, and their significance was evaluated in patients with NSCLC. The effects of a candidate gene on EGFR were investigated in vitro and in vivo. FINDINGS: We report 31 candidates that are required for cell proliferation, with the E2 ubiquitin conjugase CDC34 as the most significant one. CDC34 is elevated in tumor tissues in 76 of 114 (66.7%) NSCLCs and inversely associated with prognosis, is higher in smoker patients than nonsmoker patients, and is induced by tobacco carcinogens in normal human lung epithelial cells. Forced expression of CDC34 promotes, whereas knockdown of CDC34 inhibits, NSCLC cell proliferation in vitro and in vivo. CDC34 competes with c-Cbl to bind Y1045 to inhibit polyubiquitination and degradation of EGFR. In EGFR-L858R and EGFR-T790M/Del (exon 19)-driven lung tumor growth in mouse models, knockdown of CDC34 significantly inhibits tumor formation. INTERPRETATION: These results demonstrate that an E2 enzyme is capable of competing with E3 ligase to stabilize substrates, and CDC34 represents an attractive therapeutic target for NSCLCs. FUNDING: National Key Research and Development Program of China, National Natural Science Foundation of China, and the CAMS Innovation Fund for Medical Sciences.

Effect of electromagnetic pulse exposure on brain micro vascular permeability in rats.

OBJECTIVE: To observe the effect of electromagnetic pulse (EMP) exposure on cerebral micro vascular permeability in rats. METHODS: The whole-body of male Sprague-Dawley rats were exposed or sham exposed to 200 pulses or 400 pulses (1 Hz) of EMP at 200 kV/m. At 0.5, 1, 3, 6, and 12 h after EMP exposure, the permeability of cerebral micro vascular was detected by transmission electron microscopy and immunohistochemistry using lanthanum nitrate and endogenous albumin as vascular tracers, respectively. RESULTS: The lanthanum nitrate tracer was limited to the micro vascular lumen with no lanthanum nitrate or albumin tracer extravasation in control rat brain. After EMP exposure, the lanthanum nitrate ions reached the tight junction, basal lamina and pericapillary tissue. Similarly, the albumin immunopositive staining was identified in pericapillary tissue. The changes in brain micro vascular permeability were transient, the leakage of micro vascular vessels appeared at 1 h, and reached its peak at 3 h, and nearly recovered at 12 h, after EMP exposure. In addition, the leakage of micro vascular was more obvious after exposure of EMP at 400 pulses than after exposure of EMP at 200 pulses. CONCLUSION: Exposure to 200 and 400 pulses (1 Hz) of EMP at 200 kV/m can increase cerebral micro vascular permeability in rats, which is recoverable.

Systematic analysis of concentrations of 52 elements in tumor and counterpart normal tissues of patients with non-small cell lung cancer.

BACKGROUND: Many studies have documented the abnormal concentrations of major/trace elements in serum or malignant tissues of patients, but very few works systematically tested the concentrations of elements in tumor tissues in comparison with paired adjacent normal tissues from the same patients. METHODS: Tumor and adjacent normal lung tissues were obtained from 93 patients with previously untreated NSCLC, and 43 patients whose tumor and paired normal lung tissues reached 200 mg or more were selected for measurement of the elements' concentrations using an inductively coupled plasma-atomic emission spectrometer. RESULTS: We found that the concentrations of the 52 elements varied from 0.4 ng/g tissue (Lu, Pd, and Tm) to 1 658 000 ng/g (Na), 1 951 000 ng/g (P), and 2 495 000 ng/g (K). Thirty eight of the 52 (73.1%) elements showed approximately equal concentrations in tumor and adjacent normal lung tissues of the patients. The concentrations of nine elements (K, P, Mg, Zn, Rb, Cu, Se, Cs, and Tl) in tumor samples were significantly higher than their paired normal lung tissues, and five elements (Na, Fe, Cr, Cd, and Ge) exhibited decreased concentrations in cancer samples compared to counterpart normal lung tissues. Low Fe in tumor samples was associated with smoking history, whereas low Cr was associated with histology (squamous cell carcinoma) of the patients. CONCLUSIONS: Our results demonstrate that measurement of elements' concentrations in both cancer and paired normal tissues is important to get insights into the roles of these elements in carcinogenesis, and therapeutic approaches to normalize the elements are warranted to treat NSCLCs.

Connexin 32 downregulation is critical for chemoresistance in oxaliplatin-resistant HCC cells associated with EMT.

Background: Oxaliplatin (OXA)-based chemotherapy is critical in the management of advanced hepatocellular carcinoma (HCC); however, acquired drug resistance has largely restricted its clinical efficacy. This study aims to explore the key mechanisms and regulatory factors determining chemosensitivity in HCC. Methods: We developed OXA-resistant (OR) HCC cells and used multiple methods, including real-time RT-PCR, Western blot, immunofluorescence, transwell invasion assay, wound-healing assay, MTT assay, gene transfection, and immunohistochemistry to achieve our goals. Results: We found that OR HCC cells showed a typical epithelial-mesenchymal transition (EMT) phenotype. Meanwhile, the expression of Cx32, a major member of the liver connexin (Cx) family, was lowly expressed in OR HCC cells. Downregulation of Cx32 in parental HCC cells led to EMT induction and thereby reduced OXA cytotoxicity, while Cx32 upregulation in OR HCC cells could reverse the EMT phenotype and partially restore chemosensitivity to OXA. Finally, in human HCC tissue samples, Cx32 was positively correlated with the expression of the EMT marker E-cadherin and negatively correlated with the expression of Vimentin. Conclusion: Our findings demonstrated that downregulation of Cx32 may be an important determinant for HCC cells to acquire EMT-related acquired drug resistance to OXA, and targeting Cx32 could be a novel strategy to overcome OXA resistance in HCC.

The Aryl hydrocarbon receptor mediates tobacco-induced PD-L1 expression and is associated with response to immunotherapy.

Whether tobacco carcinogens enable exposed cells immune escape resulting in carcinogenesis, and why patients who smoke respond better to immunotherapies than non-smokers, remains poorly understood. Here we report that cigarette smoke and the carcinogen benzo(a)pyrene (BaP) induce PD-L1 expression on lung epithelial cells in vitro and in vivo, which is mediated by aryl hydrocarbon receptor (AhR). Anti-PD-L1 antibody or deficiency in AhR significantly suppresses BaP-induced lung cancer. In 37 patients treated with anti-PD-1 antibody pembrolizumab, 13/16 (81.3%) patients who achieve partial response or stable disease express high levels of AhR, whereas 12/16 (75%) patients with progression disease exhibit low levels of AhR in tumor tissues. AhR inhibitors exert significant antitumor activity and synergize with anti-PD-L1 antibody in lung cancer mouse models. These results demonstrate that tobacco smoke enables lung epithelial cells to escape from adaptive immunity to promote tumorigenesis, and AhR predicts the response to immunotherapy and represents an attractive therapeutic target.

Somatic Mutations and Splicing Variants of Focal Adhesion Kinase in Non-Small Cell Lung Cancer.

Background: Overexpression of focal adhesion kinase (FAK) has been reported in lung cancer, but the somatic mutations and alternative splicing variants of this nonreceptor tyrosine kinase remain to be investigated. Methods: FAK in 91 lung cancer patients was sequenced using genomic DNA and cDNA samples of tumor and paired normal lung tissues as templates, and the RNA-seq data of The Cancer Genome Atlas (TCGA) data set were assessed. The biological functions of abnormal FAK transcripts and their response to FAK inhibitors were analyzed in eight cell lines using tyrosine kinase activity assay, trypan blue exclusion assay, MTT (3-(4, 5)-dimethylthiahiazo (-z-y1)-3, 5-di-phenytetrazoliumromide) assay, and transwell assay. Results: We identified an internal tandem duplication (ITD), an A1004S point mutation, an exon 5-27 deletion (ΔE5-27) truncation variant, and four FAK6,7 splicing variants (containing exons for Boxes 6 and 7) in seven (7.7%) patients. Smokers had more FAK abnormalities than nonsmokers. In FAK-ITD, the sequence encoding the C-terminal of the FERM domain and kinase domain was duplicated in-frame and produced a protein product with elevated autophosphorylation and sensitivity to FAK inhibitors. FAK6,7 was detected in the tumor but not counterpart normal lung tissues of four (4.4%) patients. In TCGA RNA-seq data, Box 6 and/or Box 7 (Box 6/7)-containing FAK variants were positive in 42 (8.3%) of 508 lung adenocarcinomas (LUADs) and 37 (7.4%) of 501 lung squamous cell carcinomas, and smokers had higher expression of Box 6/7 (+) FAK than reformed or nonsmokers with LUAD. FAK6,7 promoted cell proliferation and migration, exhibited increased autophosphorylation, and was more sensitive to FAK inhibitor compared with wild-type FAK. Conclusions: Somatic mutations and splicing variants of FAK may have a role in lung carcinogenesis and represent potential biomarkers for FAK-targeted therapies.