[Effect of electroacupuncture preconditioning on expression of Gasdermin D, Caspase-1 and IL-1ß in rats with myocardial ischemia reperfusion injury].

OBJECTIVE: To observe the effect of electroacupuncture(EA) preconditioning on expression of Caspase-1, Gasdermin D(GSDMD) and interleukin-1ß(IL-1ß) in myocardial tissue of myocardial ischemia reperfusion injury (MIRI) rats in order to explore its underlying mechanisms in resisting MIRI. METHODS: Forty male rats were randomly divided into 4 groups: normal control (normal), sham operation (sham), MIRI model and EA groups. The MIRI model was established by ligation of the left anterior descending branch of the left coronary artery for 30 min and perfusion. EA (2 Hz/100 Hz, 1 mA) was applied to bilateral "Neiguan" (PC6) for 20 min, once a day for 3 consecutive days. The echocardiography was used to analyze the left ventricular end-diastolic dimension (LVEDD), left ventricular end-systolic dimension (LVESD) and left ventricular ejection fraction (LVEF, by using Teichholz formula) 4 h after modeling. The myocardial TTC staining was used to observe the proportion of the infarct area, and Western blot was used to detect the expression levels of GSDMD, Caspase-1, IL-1ß proteins in the myocardium. RESULTS: Compared with the normal group, the immunoactivity of GSDMD was increased in the sham group (P<0.05). Compared with the sham group, the LVEF was significantly decreased (P<0.000 1), while the myocardial infarction area, immunoactivity of GSDMD, and the expression levels of Caspase-1, GSDMD and IL-1ß proteins were considerably increased in the model group (P<0.000 1, P<0.001). In comparison with the model group, the decreased ejection fraction and the increased myocardial infarction area, and Caspase-1, GSDMD and IL-1ß expression were reversed in the EA group (P<0.001, P<0.000 1, P<0.01). CONCLUSION: EA preconditioning may ameliorate myocardial injury in MIRI rats which may be associated with its function in down-regulating the expression of myocardial Caspase-1 protein to reduce cardiomyocyte pyroptosis.

[Effect of electroacupuncture at "Neiguan" (PC 6) on cardiac function and inflammatory factors of acupoint area in rats with acute myocardial ischemia].

OBJECTIVE: To observe the effect of electroacupuncture (EA) at "Neiguan" (PC 6) on cardiac function and cardiomyocyte apoptosis in rats with acute myocardial ischemia (AMI), and to explore the correlation between myocardial protective effect of EA and inflammatory factors i.e. interleukin-1ß (IL-1ß) and interleukin-17 (IL-17) of "Neiguan" (PC 6) area. METHODS: A total of 40 male SD rats with normal ultrasonic cardiogram were randomized into a sham-operation group, a sham-operation plus EA group, a model group and an EA group, 10 rats in each group. The AMI model was established by ligating the left anterior descending (LAD) branch of the coronary artery in the model group and the EA group, while the threading without ligating was adopted in the sham-operation group and the sham-operation plus EA group. In the sham-operation plus EA group and the EA group, EA at bilateral "Neiguan" (PC 6) was applied, with disperse-dense wave, 2 Hz/100 Hz in frequency and 2 mA in density, once a day, 20 min a time for 3 days. The cardiac ejection fraction (EF) and fractional shortening (FS) were measured by ultrasonic cardiogram to evaluate the cardiac function, the cardiomyocyte apoptosis was detected by TUNEL staining, the infiltration of inflammatory factors of "Neiguan" (PC 6) area was observed by H.E. staining, the expression of inflammatory factors IL-1ß and IL-17 of "Neiguan" (PC 6) area was detected by immunofluorescence staining. RESULTS: Compared with the sham-operation group, EF and FS were decreased (P<0.001), the average optical density of cardiomyocyte apoptosis was increased (P<0.001), the infiltration of inflammatory factors was obvious in skin dermis of "Neiguan" (PC 6) area in the model group; the positive expression of IL-1ß and IL-17 of "Neiguan" (PC 6) area was increased in the model group and the sham-operation plus EA group (P<0.001, P<0.01). Compared with the model group, EF and FS were increased (P<0.01), the average optical density of cardiomyocyte apoptosis was decreased (P<0.01), the infiltration of inflammatory factors was aggravating in skin dermis of "Neiguan" (PC 6) area, and the positive expression of IL-1ß and IL-17 of "Neiguan" (PC 6) area was increased in the EA group (P<0.001, P<0.01). CONCLUSION: Electroacupuncture at "Neiguan" (PC 6) can improve the cardiac function and reduce the apoptosis of cardiomyocyte in rats with acute myocardial ischemia, its mechanism may be related to the regulation of the inflammatory factors of "Neiguan" (PC 6) area.

Netting Gut Disease: Neutrophil Extracellular Trap in Intestinal Pathology.

Many gut disease etiologies are attributed to the presence of robust inflammatory cell recruitment. The recruitment of neutrophils plays a vital role in inflammatory infiltration. Neutrophils have various antimicrobial effector mechanisms, including phagocytosis, oxidative burst, and degranulation. It is suggested that neutrophils could release neutrophil extracellular traps (NETs) to kill pathogens. However, recent evidence indicates that neutrophil infiltration within the gut is associated with disrupted local immunological microenvironment and impaired epithelial barrier. Growing evidence implies that NETs are involved in the progression of many diseases, including cancer, diabetes, thrombosis, and autoimmune disease. Increased NET formation was found in acute or chronic conditions, including infection, sterile inflammation, cancer, and ischemia/reperfusion injury (IRI). Here, we present a comprehensive review of recent advances in the understanding of NETs, focusing on their effects in gut disease. We also discuss NETs as a potential therapeutic target in gut disease.

[Effect of electroacupuncture on expression of IL-23/IL-17 axis and TLR4 in infarcted tissue in rats with myocardial infarction].

OBJECTIVE: To observe the effect of electroacupuncture (EA) on expression of interleukin (IL) -23/IL-17 axis and Toll-like receptor 4 (TLR4) in the infarcted tissue in rats with myocardial infarction (MI), and to explore the mechanism of EA on alleviating MI injury. METHODS: Forty male SD rats were randomly divided into a sham-operation group, a sham-operation plus EA group, a model group and an EA group, 10 rats in each group. The MI models were established by ligation of left anterior descending coronary artery in the model group and EA group, while only threading was performed in the sham-operation group and sham-operation plus EA group. The rats in the sham-operation plus EA group and EA group were treated with EA at "Neiguan" (PC 6), disperse-dense wave, 2 Hz/100 Hz, 2 mA, once a day, 20 min each time, for 3 days. After the intervention, the ejection fraction (EF) was measured by echocardiography to evaluate the cardiac function; the infarct area was measured by TTC staining; the HE staining was used to observe the morphological changes of myocardial tissue; the levels of IL-23 and IL-17 in infarcted tissue were detected by ELISA; the protein expression of TLR4 in infarcted tissue was detected by Western blot. RESULTS: Compared with the sham-operation group, the EF was decreased (P<0.01), the infarct area was increased (P<0.01), the myocardial fiber injury was obvious, accompanied by inflammatory cell infiltration, and the contents of IL-23, IL-17 and the expression of TLR4 in infarcted tissue were increased in the model group (P<0.01). Compared with the model group, the EF was increased (P<0.05), the infarct area was reduced (P<0.05), the myocardial fiber injury was significantly improved, the inflammatory cell infiltration was reduced, and the contents of IL-23, IL-17 and TLR4 expression in infarcted tissue were decreased in the EA group (P<0.05). CONCLUSION: EA may alleviate the excessive inflammatory response after MI by inhibiting the expression of IL-23/IL-17 axis in MI rats, and TLR4 may be involved during the process.

Electroacupuncture interventions alleviates myocardial ischemia reperfusion injury through regulating gut microbiota in rats.

Electroacupuncture (EA) intervention has a remarkable cardioprotection against myocardial ischemia reperfusion injury (MIRI). Recently, it has been suggested that the gut microbiota plays an important role in regulating the progression and prognosis of MIRI. The purpose of this study was to illustrate the relationship between gut microbiota and cardioprotection of EA on MIRI. We conducted a MIRI model by ligating the left anterior descending coronary artery for 30 min followed by reperfusion in male Sprague Dawley rats, which then received 7 days of EA intervention. Echocardiography was employed to evaluate left ventricular function. Fecal samples were collected for microbial analysis by 16S rDNA high-throughput sequencing. Blood samples and myocardium were collected for inflammatory cytokine detection by enzyme linked immunosorbent assay (ELISA) and Western blot. Hematoxylin & eosin (HE) staining and immunofluorescence of ileum tissue were performed for intestinal damage evaluation. After 7 days of EA intervention, the left ventricular function was improved with significantly increased ejection fraction and fractional shortening. Furthermore, we found that EA intervention reversed the changed gut microbiota induced by MIRI, including Clostridiales, RF39, S24-7, Desulfovibrio, and Allobaculum, improved the impaired gut barrier, reduced the production and circulation of lipopolysaccharide (LPS), inhibited the level of interleukin 6 (IL-6) and interleukin 12 (IL-12) in periphery and decreased the expression of Toll like receptor 4 (TLR4) and IL-6 in myocardium. EA intervention could improve the impaired gut mucosal barrier and reduce the production and circulation of LPS after MIRI through regulating gut microbiota, thus inhibiting the circulation and myocardium inflammation and finally exerted the cardioprotective effect.

[Effect of electroacupuncture pretreatment on transient receptor potential vanilloid 1(TRPV1)/calcitonin gene-related peptide(CGRP) signal and NF-κB p65 protein expression in rats with acute myocardial ischemia].

OBJECTIVE: To observe the effect of electroacupuncture(EA)pretreatment on transient receptor potential vanilloid 1(TRPV1)/calcitonin gene-related peptide(CGRP)signal and nuclear factor-κB p65 (NF-κB p65) protein expression in myocardial tissue of acute myocardial ischemic injury (AMI) rats, and to investigate the possible mechanism of electroacupuncture pretreatment against AMI. METHODS: A total of 60 adult male SD rats were randomly divided into blank control, sham operation, model and EA pretreatment groups, 15 rats in each group. The acute myocardial ischemia model was established by ligating the left anterior descending (LAD)branch of the coronary artery in the model group and EA pretreatment group, while threading but no ligating at left anterior descending branch of the coronary artery was applied in the sham operation group. In the EA pretreatment group, bilateral "Neiguan"(PC6) acupoints were selected, with intensity of 2 mA and frequency of 2 Hz/100 Hz, for 20 min, once daily for 7 days before modeling. Electrocardiogram (ECG) was recorded by physiological signal acquisition system, and the ST segment potential offset values of standard Ⅱ lead were analyzed before surgery，30 min and 24 h after operation. The TTC staining was used to observe the percentage of myocardial infarction area. The HE staining was used to observe the pathological changes of myocardial tissue and the degree of inflammatory cell infiltration. And Western blot was used to detect TRPV1/CGRP signal and NF-κB p65 protein expression levels in myocardial tissue. RESULTS: Compared with the sham operation group, the ECG-J point potential in the model group was significantly increased at 30 min and decreased at 24 h after operation (P<0.05), myocardial infarction area increased significantly (P<0.05), the myocardial fibers were obviously disordered, inflammatory cell infiltration was obvious, and the expressions of TRPV1，CGRP and NF-κB p65 proteins were all increased (P<0.05). Compared with the model group, the EA pretreatment group was decreased in the ECG-J point potential at 30 min after operation(P<0.05), significantly reduced in myocardial infarction area (P<0.05), improved in the morphology of myocardial fibers, reduced ininflammatory cell infiltration, and increased in the protein expressions of TRPV1 and CGRP in myocardium (P<0.05), significantly decreased in the protein expression of NF-κB p65 (P<0.05). CONCLUSION: EA pretreatment may enhance TRPV1/CGRP signaling, down-regulate NF-κB p65 protein expression, reduce myocardial inflammatory response status, improve AMI injury, and reduce myocardial infarction area.

Association of genetic and immuno-characteristics with clinical outcomes in patients with RET-rearranged non-small cell lung cancer: a retrospective multicenter study.

BACKGROUND: Rearranged during transfection (RET) has been proven to be a tumorigenic target in non-small cell lung cancers (NSCLCs). In RET-rearranged NSCLCs, molecular features and their impact on prognosis were not well illustrated, and the activity of mainstay therapeutics has not currently been well compared. METHODS: Patients diagnosed with NSCLCs with RET rearrangements were analyzed for concomitant mutations, tumor mutation burden (TMB), PD-L1 expression, T cell receptor repertoire and clinical outcomes with chemotherapy, immune checkpoint inhibitors (ICIs), and multikinase inhibitors (MKIs). RESULTS: Among 129 patients with RET-rearranged NSCLC who were analyzed, 41.1% (53/129) had co-occurring genetic alterations by next-generation sequencing, and concomitant TP53 mutation appeared most frequently (20/53, 37.7%). Patients with concurrent TP53 mutation (n = 15) had shorter overall survival than those without (n = 30; median, 18.4 months [95% CI, 8.6-39.1] vs 24.8 months [95% CI, 11.7-52.8]; P < 0.05). Patients with lower peripheral blood TCR diversity (n = 5) had superior overall survival compared with those with higher diversity (n = 6; median, 18.4 months [95% CI, 16.9-19.9] vs 4.8 months [95% CI, 4.5-5.3]; P = 0.035). An association with overall survival was not observed for PD-L1 expression nor for tumor mutation burden level. Median progression-free survival was not significantly different across chemotherapy, ICIs, and MKIs (median, 3.5 vs 2.5 vs 3.8 months). For patients treated with ICIs, the disease control rate was 60% (6/10) and the objective response rate was 20% (2/10). CONCLUSIONS: RET-rearranged lung cancers can be heterogeneous in terms of concomitant genetic alterations. Patients with concurrent TP53 mutation or high peripheral blood TCR repertoire diversity have relatively inferior overall survival in this series. Outcomes with traditional systemic therapies in general are suboptimal.

Association of Tumor Protein p53 and Ataxia-Telangiectasia Mutated Comutation With Response to Immune Checkpoint Inhibitors and Mortality in Patients With Non-Small Cell Lung Cancer.

Importance: Immune checkpoint inhibitors (ICIs) can elicit durable antitumor responses in patients with non-small cell lung cancer (NSCLC), but only 20% to 25% of patients respond to treatment. As important genes in the DNA damage response pathway, comutation in the tumor protein p53 (TP53) and ataxia-telangiectasia mutated (ATM) genes may be associated with genomic instability and hypermutation. However, the prevalence of TP53 and ATM comutation and its association with response to ICIs are not fully understood. Objective: To examine the prevalence of the TP53 and ATM comutation, the potential mechanism, and its association with response to ICIs among patients with NSCLC. Design, Setting, and Participants: This multiple-cohort study included patients with NSCLC from the Geneplus Institute, the Cancer Genome Atlas (TCGA), and the Memorial Sloan Kettering Cancer Center (MSKCC) databases and from the POPLAR and OAK randomized controlled trials. Samples in the Geneplus cohort were collected and analyzed from April 30, 2015, through February 28, 2019. Data from TCGA, the MSKCC, and the POPLAR and OAK cohorts were obtained on January 1, 2019, and analyzed from January 1 to April 10, 2019. Next-generation sequencing assays were performed on tumor samples by the Geneplus Institute. Genomic, transcriptomic, and clinical data were obtained from TCGA and MSKCC databases. Exposures: Comprehensive genetic profiling was performed to determine the prevalence of TP53 and ATM comutation and its association with prognosis and response to ICIs. Main Outcomes and Measures: The main outcomes were TP53 and ATM comutation frequency, overall survival (OS), progression-free survival, gene set enrichment analysis, and immune profile in NSCLC. Results: Patients with NSCLC analyzed in this study included 2020 patients in the Geneplus cohort (mean [SD] age, 59.5 [10.5] years; 1168 [57.8%] men), 1031 patients in TCGA cohort (mean [SD] age, 66.2 [9.5] years; 579 [56.2%] men), 1527 patients in the MSKCC cohort (662 [43.4%] men), 350 patients in the MSKCC cohort who were treated with ICIs (mean [SD] age, 61.4 [13.8] years; 170 [48.6%] men), and 853 patients in the POPLAR and OAK cohort (mean [SD] age, 63.0 [9.1] years; 527 [61.8%] men). Sites of TP53 and ATM comutation were found scattered throughout the genes, and no significant difference was observed in the frequency of TP53 and ATM comutation within the histologic subtypes and driver genes. In 5 independent cohorts of patients with NSCLC, TP53 and ATM comutation was associated with a significantly higher tumor mutation burden compared with the sole mutation and with no mutation (TCGA, MSKCC, Geneplus, and POPLAR and OAK cohort). Among patients treated with ICIs in the MSKCC cohort, TP53 and ATM comutation was associated with better OS than a single mutation and no mutation among patients with any cancer (median OS: TP53 and ATM comutation, not reached; TP53 mutation alone, 14.0 months; ATM mutation alone, 40.0 months; no mutation, 22.0 months; P = .001; NSCLC median OS: TP53 and ATM comutation, not reached; TP53 mutation alone, 11.0 months; ATM mutation alone, 16.0 months; no mutation, 14.0 months; P = .24). Similar results were found in the POPLAR and OAK cohort in which the disease control benefit rate, progression-free survival, and OS were all greater in patients with the TP53 and ATM comutation compared with the other 3 groups (median progression-free survival: TP53 and ATM comutation, 10.4 months; TP53 mutation, 1.6 months; ATM mutation, 3.5 months; no mutation, 2.8 months; P = .01; median OS: TP53 and ATM comutation, 22.1 months; TP53 mutation, 8.3 months; ATM mutation, 15.8 months; no mutation, 15.3 months; P = .002). Conclusions and Relevance: This study's findings suggest that the TP53 and ATM comutation occurs in a subgroup of patients with NSCLC and is associated with an increased tumor mutation burden and response to ICIs. This suggests that TP53 and ATM comutation may have implications as a biomarker for guiding ICI treatment.

Characteristics and prognostic significance of profiling the peripheral blood T-cell receptor repertoire in patients with advanced lung cancer.

Lung cancer is one of the greatest threats to human health, and is initially detected and attacked by the immune system through tumor-reactive T cells. The aim of this study was to determine the basic characteristics and clinical significance of the peripheral blood T-cell receptor (TCR) repertoire in patients with advanced lung cancer. To comprehensively profile the TCR repertoire, high-throughput sequencing was used to identify hypervariable rearrangements of complementarity determining region 3 (CDR3) of the TCR ß chain in peripheral blood samples from 64 advanced lung cancer patients and 31 healthy controls. We found that the TCR repertoire differed substantially between lung cancer patients and healthy controls in terms of CDR3 clonotype, diversity, V/J segment usage, and sequence. Specifically, baseline diversity correlated with several clinical characteristics, and high diversity reflected a better immune status. Dynamic detection of the TCR repertoire during anticancer treatment was useful for prognosis. Both increased diversity and high overlap rate between the pre- and post-treatment TCR repertoires indicated clinical benefit. Combination of the diversity and overlap rate was used to categorize patients into immune improved or immune worsened groups and demonstrated enhanced prognostic significance. In conclusion, TCR repertoire analysis served as a useful indicator of disease development and prognosis in advanced lung cancer and may be utilized to direct future immunotherapy.

Hypoxia-Induced Epithelial-to-Mesenchymal Transition in Hepatocellular Carcinoma Induces an Immunosuppressive Tumor Microenvironment to Promote Metastasis.

Portal vein tumor thrombosis (PVTT) is a significant risk factor for metastasis in hepatocellular carcinoma (HCC) patients and is therefore associated with poor prognosis. The presence of PVTT frequently accompanies substantial hypoxia within the tumor microenvironment, which is suggested to accelerate tumor metastasis, but it is unclear how this occurs. Recent evidence has shown that the hypoxia-inducible factor HIF-1α induces epithelial-to-mesenchymal transition (EMT) in tumor cells to facilitate metastasis. In this study, we investigated whether hypoxia-induced EMT in cancer cells also affects immune cells in the tumor microenvironment to promote immunosuppression. We found that hypoxia-induced EMT increased the expression of the CCL20 cytokine in hepatoma cells. Furthermore, coculture of monocyte-derived macrophages with hypoxic hepatoma cells revealed that the expression of indoleamine 2, 3-dioxygenase (IDO) was induced in monocyte-derived macrophages in a CCL20-dependent manner. In turn, these IDO-expressing monocyte-derived macrophages suppressed T-cell proliferation and promoted the expansion of immunosuppressive regulatory T cells. Moreover, high CCL20 expression in HCC specimens was associated with PVTT and poor patient survival. Collectively, our findings suggest that the HIF-1α/CCL20/IDO axis in hepatocellular carcinoma is important for accelerating tumor metastasis through both the induction of EMT and the establishment of an immunosuppressive tumor microenvironment, warranting further investigation into the therapeutic effects of blocking specific nodes of this signaling network.

Rapamycin enhances cetuximab cytotoxicity by inhibiting mTOR-mediated drug resistance in mesenchymal hepatoma cells.

The synergistic effect of combined drug therapy provides an enhanced treatment for advanced liver cancer. We aimed to investigate the underlying mechanism of cetuximab sensitization by rapamycin in hepatoma cells. Four hepatoma cell lines, HepG2, HuH7, SNU-387, and SNU-449, were treated with cetuximab or cetuximab plus rapamycin and growth inhibition was evaluated by measuring relative cell viability and cell proliferation. The cell phenotype was determined for each hepatoma cell line by western blot analysis of E-cadherin and vimentin expression and mTOR activation status. To identify the role of mTOR signaling in cetuximab sensitization, we used deferoxamine-mediated hypoxia to induce epithelial-mesenchymal transition (EMT) in HuH7 and HepG2 cells and measured mTOR activity after rapamycin treatment. Rapamycin significantly increased cetuximab cytotoxicity in hepatoma cell lines with differential sensitivities. Phenotypic differences among hepatoma cell lines, specifically epithelial (HuH7 and HepG2) and mesenchymal (SNU-387 and SNU-449), correlated with the efficacy of rapamycin cotreatment, although rapamycin treatment did not affect cell phenotype. We further showed that rapamycin inhibits mTOR in mesenchymal SNU-387 and SNU-449 cells. In addition, the induction of EMT in HuH7 and HepG2 cells significantly decreased cetuximab cytotoxicity; however, rapamycin treatment significantly restored cetuximab sensitivity and decreased mTOR signaling in these cells. In conclusion, we identified significant differences in rapamycin-induced cetuximab sensitization between epithelial and mesenchymal hepatoma cells. We therefore report that rapamycin cotreatment enhances cetuximab cytotoxicity by inhibiting mTOR signaling in mesenchymal cells.

Establishment of an experimental mouse model of trauma-hemorrhagic shock.

This study established an experimental mouse model of trauma-hemorrhagic shock (THS). THS-induced mice (C57BL/6J, n=33) were subjected to femoral fracture, ischemia for 90 min, and resuscitation for 15 min. The sham-operated mice (C57BL/6J, n=33) underwent the same anesthetic and surgical procedures, but neither trauma-hemorrhage nor fluid resuscitation were performed. Mean arterial pressure (MAP) and microvascular tissue perfusion over the small intestine, liver, and left kidney were longitudinally measured in all mice. Blood was collected for analysis at baseline and 3, 6, 12, and 24 h post resuscitation, and the small intestine, liver, and left kidney were resected for hematoxylin and eosin staining 24 h post resuscitation. Compared with the sham group, MAP and microvascular tissue perfusion over the small intestine, liver, and left kidney were all significantly reduced in the THS group at the end of hemorrhage. Following resuscitation, no significant differences were observed between the groups. THS induction was associated with significantly increased plasma concentrations of Cr, AST, CPK, IL-6, IL-10, and TNF-α from the baseline values by two- to three-fold after the hemorrhage phase, and THS-induced mice demonstrated significantly increased histological injury scores. The rapid drop in MAP and microvascular tissue perfusion observed following THS induction, and the gradual recovery post resuscitation, reflects the successful establishment of a THS experimental mouse model.

NSC 74859 enhances doxorubicin cytotoxicity via inhibition of epithelial-mesenchymal transition in hepatocellular carcinoma cells.

Doxorubicin-based therapy is not effective for the treatment of hepatocellular carcinomas (HCCs), which often undergo epithelial-mesenchymal transition (EMT) during tumor progression. Activation of signal transducer and activator of transcription 3 (STAT3) is associated with chemosensitivity and may contribute to EMT during HCC chemotherapy. Low doses of NSC 78459 (a novel STAT3 inhibitor) have little effect on HCC cell proliferation, but efficiently inhibit STAT3. HuH-7, Hep3B, and HepG2 cells, with epithelial phenotypes, show significantly enhanced doxorubicin cytotoxicity following co-treatment with NSC 74859, whereas mesenchymal SNU-449 cells show no such enhancement. NSC 74859 inhibits STAT3 activity and suppressed doxorubicin-induced EMT in epithelial HCC cells. siRNA-mediated STAT3 knockdown resulted in EMT inhibition, which led to attenuation of NSC 74859-mediated chemosensitivity. Our data indicate NSC 74859 co-administration enhances doxorubicin cytotoxicity by inhibiting STAT3 in epithelial HCC cells. STAT3 deactivation and associated EMT attenuation contribute to the synergistic anti-tumor effects of combined NSC 74859/doxorubicin therapy.

Macrophage-induced tumor angiogenesis is regulated by the TSC2-mTOR pathway.

Tumor-associated macrophages (TAM) have multifaceted roles in tumor development but they have been associated particularly closely with tumor angiogenesis. However, although the accumulation of TAM (M2 phenotype) promotes tumor angiogenesis, the mechanism through which monocytes differentiate to generate TAM is unclear. Here, we report that the mTOR pathway is a critical element in the regulation of monocyte differentiation to TAM. In human peripheral monocytes stimulated by lipopolysaccharide, mTOR was inhibited by rapamycin or activated by RNA interference-mediated knockdown of the mTOR repressor tuberous sclerosis complex 2 (TSC2). Rapamycin caused the monocytes to differentiate into M1 macrophages releasing more interleukin (IL)-12 and less IL-10, whereas TSC2 knockdown caused the monocytes to differentiate into M2 macrophages releasing less IL-12 and more IL-10. In parallel fashion, angiogenic properties were promoted or reduced in human umbilical vein endothelial cells cocultured with TSC2-deficient monocytes or rapamycin-treated monocytes, respectively. Furthermore, tumor angiogenesis and growth in murine xenografts were promoted or reduced by infusion of hosts with TSC2-deficient or TSC2-overexpressing monocytes, respectively. Finally, in vivo depletion of macrophages was sufficient to block the antiangiogenic effects of rapamycin on tumors. Our results define the TSC2-mTOR pathway as a key determinant in the differentiation of monocytes into M2 phenotype TAM that promote angiogenesis.