Structure of Polysaccharide from Dendrobium nobile Lindl. and Its Mode of Action on TLR4 to Exert Immunomodulatory Effects.

Dendrobium nobile Lindl. polysaccharide (DNP1) showed good anti-inflammatory activity in our previous study. In this study, the structural characterization of DNP1 and its mode of action on TLR4 were investigated. Structural characterization suggested that DNP1 was a linear glucomannan composed of (1 → 4)-ß-Manp and (1 → 4)-ß-Glcp residues, and the acetyl group was linked to the C-2 of Manp. The possible repeating structural units of DNP1 were [→4)-2-OAc-ß-Manp-(1→]3 →4)-ß-Glcp-(1→. Surface plasmon resonance (SPR) binding test results showed that DNP1 did not bind directly to TLR4. The TLR4 and MD2 receptor blocking tests confirmed that DNP1 needs MD2 and TLR4 to participate in its anti-inflammatory effect. The binding energy of DNP1 to TLR4-MD2 was -7.9 kcal/mol, indicating that DNP1 could bind to the TLR4-MD2 complex stably. Therefore, it is concluded that DNP1 may play an immunomodulatory role by binding to the TLR4-MD2 complex and inhibiting the TLR4-MD2-mediated signaling pathway.

PDE4D/cAMP/IL-23 axis determines the immunotherapy efficacy of lung adenocarcinoma via activating the IL-9 autocrine loop of cytotoxic T lymphocytes.

Although immunotherapy has changed the prognosis of many advanced malignancies including lung adenocarcinoma (LUAD), many patients are insensitive to the drugs, with the mechanisms yet to be elucidated. Herein, we identified PDE4D as an immunotherapy efficacy-related gene through bioinformatics screening. By using a co-culture system of LUAD cells and tumor-cell-specific CD8+ T cells, a functional PDE4D/cAMP/IL-23 axis was further revealed in LUAD cells. Fluorescent multiplex immunohistochemistry analysis of patient-derived samples and the in vivo mouse LUAD xenograft tumors revealed not only the colocalization of IL-23 and CD8+ T cells but also the immune potentiating effect of IL-23 on cytotoxic T lymphocytes (CTLs) in LUAD tissues. Through transcriptome sequencing and functional validations, IL-23 was proven to up-regulate IL-9 expression in CTLs via activating the NF-κB signaling, leading to elevated productions of immune effector molecules and enhanced efficacy of antitumor immunotherapy. Interestingly, an autocrine loop of IL-9 was also uncovered during this process. In conclusion, PDE4D/cAMP/IL-23 axis determines the immunotherapy efficacy of human LUAD. This effect is mediated by the activation of an NF-κB-dependent IL-9 autocrine loop in CTLs.

Platelets in the tumor microenvironment and their biological effects on cancer hallmarks.

The interplay between platelets and tumors has long been studied. It has been widely accepted that platelets could promote tumor metastasis. However, the precise interactions between platelets and tumor cells have not been thoroughly investigated. Although platelets may play complex roles in multiple steps of tumor development, most studies focus on the platelets in the circulation of tumor patients. Platelets in the primary tumor microenvironment, in addition to platelets in the circulation during tumor cell dissemination, have recently been studied. Their effects on tumor biology are gradually figured out. According to updated cancer hallmarks, we reviewed the biological effects of platelets on tumors, including regulating tumor proliferation and growth, promoting cancer invasion and metastasis, inducing vasculature, avoiding immune destruction, and mediating tumor metabolism and inflammation.

Dietary ketone body-escalated histone acetylation in megakaryocytes alleviates chemotherapy-induced thrombocytopenia.

Chemotherapy-induced thrombocytopenia (CIT) is a severe complication in patients with cancer that can lead to impaired therapeutic outcome and survival. Clinically, therapeutic options for CIT are limited by severe adverse effects and high economic burdens. Here, we demonstrate that ketogenic diets alleviate CIT in both animals and humans without causing thrombocytosis. Mechanistically, ketogenic diet-induced circulating ß-hydroxybutyrate (ß-OHB) increased histone H3 acetylation in bone marrow megakaryocytes. Gain- and loss-of-function experiments revealed a distinct role of 3-ß-hydroxybutyrate dehydrogenase (BDH)-mediated ketone body metabolism in promoting histone acetylation, which promoted the transcription of platelet biogenesis genes and induced thrombocytopoiesis. Genetic depletion of the megakaryocyte-specific ketone body transporter monocarboxylate transporter 1 (MCT1) or pharmacological targeting of MCT1 blocked ß-OHB-induced thrombocytopoiesis in mice. A ketogenesis-promoting diet alleviated CIT in mouse models. Moreover, a ketogenic diet modestly increased platelet counts without causing thrombocytosis in healthy volunteers, and a ketogenic lifestyle inversely correlated with CIT in patients with cancer. Together, we provide mechanistic insights into a ketone body-MCT1-BDH-histone acetylation-platelet biogenesis axis in megakaryocytes and propose a nontoxic, low-cost dietary intervention for combating CIT.

ITCH facilitates proteasomal degradation of TXNIP in hypoxia- induced lung cancer cells.

BACKGROUND: Lung cancer (LC) is one of the most common cancers and a leading cause of cancer-related deaths worldwide. In many pathological conditions, particularly in the tumor microenvironment, cells and tissues frequently exist in a hypoxic state. Here, we evaluated Itchy E3 ubiquitin protein ligase (ITCH) expression in LC cells following hypoxia treatment. METHODS: LC cell lines were treated with hypoxic condition. Cell migration, invasion, inflammation, reactive oxygen species (ROS) production, and apoptosis of LC cells were determined by wound healing assay, Transwell invasive assay, ELISA, DCFH-DA staining, and flow cytometry, respectively. qPCR and WB were used to determine the expression of ITCH and TXNIP. Co-IP was performed to assess the interaction between ITCH and TXNIP. RESULTS: ITCH expression was downregulated in LC cells under hypoxic conditions. Next, LC cells were subjected to hypoxic conditions and changes in cell viability and metastasis were determined. Hypoxic conditions resulted in increased migration and invasion abilities of LC cells. Intracellular reactive oxygen species (ROS) production, inflammation, and apoptosis were also promoted by hypoxia. We found that ITCH overexpression led to the proteasomal degradation of thioredoxin-interacting protein (TXNIP), whereas the expression of the ITCH C830A mutant did not affect TXNIP levels in LC cells. The gain-of-function experiment demonstrated that migration, invasion, ROS generation, inflammation, and apoptosis of hypoxia-conditioned LC cells were ameliorated by ITCH overexpression, whereas the ITCH C830A mutant did not cause any changes in these phenotypes. Furthermore, the contribution of TXNIP knockdown and ITCH overexpression to the hypoxia-induced features in LC cells with ITCH C830A was found to be similar. CONCLUSION: Our results suggest a novel mechanism underlying the changes in ITCH-mediated malignant phenotypes of hypoxia-conditioned LC cells via TXNIP.

Megakaryocytes Mediate Hyperglycemia-Induced Tumor Metastasis.

High blood glucose has long been established as a risk factor for tumor metastasis, yet the molecular mechanisms underlying this association have not been elucidated. Here we describe that hyperglycemia promotes tumor metastasis via increased platelet activity. Administration of glucose, but not fructose, reprogrammed the metabolism of megakaryocytes to indirectly prime platelets into a prometastatic phenotype with increased adherence to tumor cells. In megakaryocytes, a glucose metabolism-related gene array identified the mitochondrial molecular chaperone glucose-regulated protein 75 (GRP75) as a trigger for platelet activation and aggregation by stimulating the Ca2+-PKCα pathway. Genetic depletion of Glut1 in megakaryocytes blocked MYC-induced GRP75 expression. Pharmacologic blockade of platelet GRP75 compromised tumor-induced platelet activation and reduced metastasis. Moreover, in a pilot clinical study, drinking a 5% glucose solution elevated platelet GRP75 expression and activated platelets in healthy volunteers. Platelets from these volunteers promoted tumor metastasis in a platelet-adoptive transfer mouse model. Together, under hyperglycemic conditions, MYC-induced upregulation of GRP75 in megakaryocytes increases platelet activation via the Ca2+-PKCα pathway to promote cancer metastasis, providing a potential new therapeutic target for preventing metastasis. SIGNIFICANCE: This study provides mechanistic insights into a glucose-megakaryocyte-platelet axis that promotes metastasis and proposes an antimetastatic therapeutic approach by targeting the mitochondrial protein GRP75.

Stress-induced upregulation of TNFSF4 in cancer-associated fibroblast facilitates chemoresistance of lung adenocarcinoma through inhibiting apoptosis of tumor cells.

Stress conditions induced by routine treatments might affect cancer-associated fibroblasts in lung adenocarcinoma. The present study tried to explore transcriptome changes in lung fibroblasts under chemotherapeutics, irradiation, and hypoxia, which were induced by chemotherapy, radiotherapy, and anti-angiogenesis therapy, respectively. We established three in vitro models to mimic the stress conditions for lung fibroblasts. Interestingly, one of the secretory molecules, tumor necrosis factor superfamily member 4 (TNFSF4, also known as OX40L), was significantly up-regulated in lung fibroblasts under stress environments. Lung adenocarcinoma patients received chemotherapy and radiotherapy had a higher expression level of TNFSF4 in serum and tumor tissues. There was a negative correlation between the increase of serum TNFSF4 levels and the shrink of the tumor after chemotherapy. TNFSF4 could promote cisplatin resistance and inhibit the apoptosis of lung adenocarcinoma cells. Furthermore, TNFSF4 could significantly increase the activity of NF-κB/BCL-XL pathway in lung adenocarcinoma cells, which could be counteracted by knocking down the expression of TNFRSF4 (receptor of TNFSF4). In conclusion, TNFSF4, secreted by cancer-associated fibroblasts under stress conditions, could facilitate chemoresistance of lung adenocarcinoma through inhibiting apoptosis of tumor cells.

The overexpression of maspin increases the sensitivity of lung adenocarcinoma drug-resistant cells to docetaxel in vitro and in vivo.

BACKGROUND: In this study, we found that maspin affects the development of drug resistance in lung adenocarcinoma. Therefore, it is important to clarify the role and mechanism of mammary serine protease inhibitor (maspin) in the regulation of adenocarcinoma drug resistance in order to improve individualized clinical treatment protocols and drug resistance interventions. METHODS: Immunohistochemical was used to detect maspin expression in tissue chip samples of 75 patients diagnosed with lung adenocarcinoma and treated with a taxus chemotherapy regimen, and the correlation between maspin, clinicopathological factors, and prognosis was analyzed. The expression of maspin in a human lung adenocarcinoma docetaxel-resistant cell line, SPC-A1/DTX, and its parent cells were detected by reverse transcription polymerase chain reaction (RT-PCR) and western blot assay. MTT and flow cytometry were used to detect the effects of knockdown or overexpression of maspin on chemotherapy sensitivity and apoptosis in lung cancer cells. Tumor cells were also analyzed in vivo to determine their tumorigenic ability and susceptibility to docetaxel. RESULTS: Maspin is poorly expressed in lung adenocarcinoma tissue chips that have received a taxus chemotherapy regimen, and is also closely related to poor grading, late stage, lymph node metastasis, and poor prognosis. Maspin has a low expression in drug-resistant cells, and the expression level of maspin decreases significantly with increases in docetaxel concentration and over time. In drug-resistant cells, knockdown of maspin can significantly affect the sensitivity of drug-resistant cells to docetaxel. In the chemotherapy-sensitive strain SPC-A1, maspin was mainly located in the cell nucleus, while in the chemotherapy-resistant strain SPC-A1/DTX, maspin was mainly located in the cytoplasm. An in vivo nude mouse xenograft model showed that an overexpression of maspin significantly increased the inhibitory effect of docetaxel on tumor-bearing tissues and the apoptosis rate, and markedly reduced tumor weight, volume, and the Ki-67-positive rate. CONCLUSIONS: In vitro and in vivo experiments show that overexpression of maspin can increase the sensitivity of lung cancer drug-resistant cells to chemotherapy drugs, suggesting that the expression level of maspin could be used as a molecular marker to predict lung cancer drug resistance to docetaxel.

The functional role of long non-coding RNAs and their underlying mechanisms in drug resistance of non-small cell lung cancer.

BACKGROUND: Non-small cell lung cancer (NSCLC) is the most commonly diagnosed solid cancer and the main origin of cancer-related deaths worldwide. Current strategies to treat advanced NSCLC are based on a combined approach of targeted therapy and chemotherapy. But most patients will eventually get resistance to either chemotherapy or targeted therapy, leading to the poor prognosis. The mechanism of NSCLC drug resistance is inconclusive and is affected by multiple factors. Long non-coding RNAs (LncRNAs) are non-coding RNAs (ncRNAs) longer than 200 nucleotides. Recent studies show that lncRNAs are involved in many cellular physiological activities, including drug resistance of NSCLC. It is of great clinical significance to understand the specific mechanisms and the role of lncRNAs in it. CONCLUSIONS: Herein, we focus on the functional roles and the underlying mechanisms of lncRNAs in acquired drug resistance of NSCLC. LncRNAs have potential values as novel prognostic biomarkers and even therapeutic targets in the clinical management of NSCLC.

Clinical outcomes and prognostic factors of stereotactic body radiation therapy combined with gemcitabine plus capecitabine for locally advanced unresectable pancreatic cancer.

PURPOSE: This study aimed to evaluate the clinical outcomes, toxicity, and prognostic factors of SBRT combined with gemcitabine plus capecitabine (GEM-CAP) in treating locally advanced pancreatic cancer (LAPC). METHODS: A total of 56 patients with LAPC treated with SBRT combined with GEM-CAP were reviewed from October 2010 to October 2016. The median total prescription dose at five fractions was 40 Gy (30-50 Gy). The patients were subjected to two cycles of GEM-CAP before SBRT. GEM-CAP chemotherapy was then offered for four cycles or until disease tolerance or progression. The primary endpoints included overall survival (OS) and progression-free survival (PFS). RESULTS: The median OS and PFS from the date of diagnosis was 19 (95% CI 14.6-23.4) and 12 months (95% CI 8.34-15.66), respectively. The 1-year and 2-year survival rates were 82.1% and 35.7%, whereas the 1-year and 2-year PFS rates were 48.2% and 14.3%, respectively. The median carbohydrate antigen 19-9-determined PFS time was 11 months (95% CI 5.77-16.24). Multivariate analysis demonstrated that tumor diameter, lymph node metastasis, pre-treatment CA19-9 level, and post-treatment CA19-9 decline were independent prognostic factors (p < 0.05). Acute toxicity was minimal, with two cases (3.6%) experiencing grade 3 duodenal obstruction. No adverse events greater than grade 3 occurred. In late toxicity, three patients (5.4%) developed grade 3 gastrointestinal toxicity and two (3.6%) suffered from perforation caused by grade 4 radiation enteritis and intestinal fistula. CONCLUSIONS: The combination of Cyberknife SBRT and GEM-CAP achieved excellent efficacy with acceptable toxicity for LAPC.

Aurora-a confers radioresistance in human hepatocellular carcinoma by activating NF-κB signaling pathway.

BACKGROUND: Radiotherapy failure is a significant clinical challenge due to the development of resistance in the course of treatment. Therefore, it is necessary to further study the radiation resistance mechanism of HCC. In our early study, we have showed that the expression of Aurora-A mRNA was upregulated in HCC tissue samples or cells, and Aurora-A promoted the malignant phenotype of HCC cells. However, the effect of Aurora-A on the development of HCC radioresistance is not well known. METHODS: In this study, colony formation assay, MTT assays, flow cytometry assays, RT-PCR assays, Western blot, and tumor xenografts experiments were used to identify Aurora-A promotes the radioresistance of HCC cells by decreasing IR-induced apoptosis in vitro and in vivo. Dual-luciferase reporter assay, MTT assays, flow cytometry assays, and Western blot assay were performed to show the interactions of Aurora-A and NF-κB. RESULTS: We established radioresistance HCC cell lines (HepG2-R) and found that Aurora-A was significantly upregulated in those radioresistant HCC cells in comparison with their parental HCC cells. Knockdown of Aurora-A increased radiosensitivity of radioresistant HCC cells both in vivo and in vitro by enhancing irradiation-induced apoptosis, while upregulation of Aurora-A decreased radiosensitivity by reducing irradiation-induced apoptosis of parental cells. In addition, we have showed that Aurora-A could promote the expression of nuclear IkappaB-alpha (IκBα) protein while enhancing the activity of NF-kappaB (κB), thereby promoted expression of NF-κB pathway downstream effectors, including proteins (Mcl-1, Bcl-2, PARP, and caspase-3), all of which are associated with apoptosis. CONCLUSIONS: Aurora-A reduces radiotherapy-induced apoptosis by activating NF-κB signaling, thereby contributing to HCC radioresistance. Our results provided the first evidence that Aurora-A was essential for radioresistance in HCC and targeting this molecular would be a potential strategy for radiosensitization in HCC.

S1PR1 promotes proliferation and inhibits apoptosis of esophageal squamous cell carcinoma through activating STAT3 pathway.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers worldwide, which lacks effective biomarkers for prognosis. Therefore, it is urgent to explore new potential molecular markers to discriminate patients with poorer survival in ESCC. METHODS: Bioinformatics analysis, qRT-PCR, and western blot were applied to investigate S1PR1 expression. CCK-8 assay, colony formation assay, flow cytometry dual staining assay, and immunofluorescence were performed to examine cell proliferation ability and apoptosis rate. Mouse xenograft model of TE-13 cells was established to confirm the roles of S1PR1 in vivo. Gene set enrichment analysis (GSEA) was used to investigate the downstream signaling pathways related to S1PR1 functions. Co-IP was performed to verify the direct binding of S1PR1 and STAT3. Western blot was applied to determine the phosphorylation level of STAT3. Immunohistochemistry was conducted to identify protein expression of S1PR1 and p- STAT3 in tumor tissues. RESULTS: In the present study, we found that S1PR1 expression was higher in ESCC patients and was a potential biomarker for poor prognosis. Silencing S1PR1 expression inhibited proliferation, and increased apoptosis of ESCC cells, while overexpression of S1PR1 had opposite effects. Mechanistically, S1PR1 played the roles of promoting proliferation and attenuating apoptosis through directly activating p-STAT3. Furthermore, in vivo experiments verified this mechanism. CONCLUSION: Our findings indicated that S1PR1 enhanced proliferation and inhibited apoptosis of ESCC cells by activating STAT3 signaling pathway. S1PR1 may serve as a prognostic biomarker for clinical applications.

miRNA­885­3p inhibits docetaxel chemoresistance in lung adenocarcinoma by downregulating Aurora A.

Aurora A is a member of the mitotic serine/threonine kinase family. It is involved in key processes during mitosis and meiosis, and Aurora A upregulation is implicated in malignant transformation. In the present study, we revealed that Aurora A expression was significantly higher in docetaxel­resistant lung adenocarcinoma (LAD) cells than in parental cells. Higher levels of Aurora A expression were significantly correlated with higher chemoresistance and proliferation in LAD cells, while silencing Aurora A promoted caspase­3­dependent cell apoptosis by downregulating NF­κB and Bcl­2 and upregulating Bax expression. In addition, an increased proportion of cells in the G2/M phase and a decreased proportion of cells in the S phase were observed due to the suppression of Aurora A. Furthermore, we identified that microRNA­885­3p (miR­885­3p) could target Aurora A directly. There was significantly lower miR­885­3p expression in docetaxel­resistant LAD cells than in parental LAD cells. miR­885­3p could modulate the docetaxel response, cell proliferation and apoptosis in LAD cells in vitro. Moreover, we found that Aurora A overexpression or miR­885­3p inhibition was associated with more aggressive behaviour in LAD cells. Thus, miR­885­3p/Aurora A may be involved in the chemoresistance of LAD cells, and assessing miR­885­3p/Aurora A expression may be a potential method for indicating chemosensitivity to docetaxel­based chemotherapy.

Wnt signaling induces radioresistance through upregulating HMGB1 in esophageal squamous cell carcinoma.

Although many articles have uncovered that Wnt signaling is involved in radioresistance, the mechanism is rarely reported. Here we generated two radioresistant cells rECA109 and rKyse150 from parental esophageal cancer cells ECA109 and Kyse150. We then found that Wnt signaling activity was higher in radioresistant cells and was further activated upon ionizing radiation (IR) exposure. In addition, radioresistant cells acquired epithelial-to-mesenchymal transition (EMT) properties and stem quality. Wnt signaling was then found to be involved in radioresistance by promoting DNA damage repair. In our present study, high-mobility group box 1 protein (HMGB1), a chromatin-associated protein, was firstly found to be transactivated by Wnt signaling and mediate Wnt-induced radioresistance. The role of HMGB1 in the regulation of DNA damage repair with the activation of DNA damage checkpoint response in response to IR was the main cause of HMGB1-induced radioresistance.

Off-tumor targets compromise antiangiogenic drug sensitivity by inducing kidney erythropoietin production.

Anti-VEGF drugs are commonly used for treatment of a variety of cancers in human patients, and they often develop resistance. The mechanisms underlying anti-VEGF resistance in human cancer patients are largely unknown. Here, we show that in mouse tumor models and in human cancer patients, the anti-VEGF drug-induced kidney hypoxia augments circulating levels of erythropoietin (EPO). Gain-of-function studies show that EPO protects tumor vessels from anti-VEGF treatment and compromises its antitumor effects. Loss of function by blocking EPO function using a pharmacological approach markedly increases antitumor activity of anti-VEGF drugs through inhibition of tumor angiogenesis. Similarly, genetic loss-of-function data shows that deletion of EpoR in nonerythroid cells significantly increases antiangiogenic and antitumor effects of anti-VEGF therapy. Finally, in a relatively large cohort study, we show that treatment of human colorectal cancer patients with bevacizumab augments circulating EPO levels. These findings uncover a mechanism of desensitizing antiangiogenic and anticancer effects by kidney-produced EPO. Our work presents conceptual advances of our understanding of mechanisms underlying antiangiogenic drug resistance.

Cancer associated fibroblasts: An essential role in the tumor microenvironment.

Fibroblasts in the tumor stroma are well recognized as having an indispensable role in carcinogenesis, including in the initiation of epithelial tumor formation. The association between cancer cells and fibroblasts has been highlighted in several previous studies. Regulation factors released from cancer-associated fibroblasts (CAFs) into the tumor microenvironment have essential roles, including the support of tumor growth, angiogenesis, metastasis and therapy resistance. A mutual interaction between tumor-induced fibroblast activation, and fibroblast-induced tumor proliferation and metastasis occurs, thus CAFs act as tumor supporters. Previous studies have reported that by developing fibroblast-targeting drugs, it may be possible to interrupt the interaction between fibroblasts and the tumor, thus resulting in the suppression of tumor growth, and metastasis. The present review focused on the reciprocal feedback loop between fibroblasts and cancer cells, and evaluated the potential application of anti-CAF agents in the treatment of cancer.

Maintenance of antiangiogenic and antitumor effects by orally active low-dose capecitabine for long-term cancer therapy.

Long-term uninterrupted therapy is essential for maximizing clinical benefits of antiangiogenic drugs (AADs) in cancer patients. Unfortunately, nearly all clinically available AADs are delivered to cancer patients using disrupted regimens. We aim to develop lifetime, nontoxic, effective, orally active, and low-cost antiangiogenic and antitumor drugs for treatment of cancer patients. Here we report our findings of long-term maintenance therapy with orally active, nontoxic, low cost antiangiogenic chemotherapeutics for effective cancer treatment. In a sequential treatment regimen, robust antiangiogenic effects in tumors were achieved with an anti-VEGF drug, followed by a low-dose chemotherapy. The nontoxic, low dose of the orally active prodrug capecitabine was able to sustain the anti-VEGF-induced vessel regression for long periods. In another experimental setting, maintenance of low-dose capecitabine produced greater antiangiogenic and antitumor effects after AAD plus chemotherapy. No obvious adverse effects were developed after more than 2-mo of consecutive treatment with a low dose of capecitabine. Together, our findings provide a rationalized concept of effective cancer therapy by long-term maintenance of AAD-triggered antiangiogenic effects with orally active, nontoxic, low-cost, clinically available chemotherapeutics.

Cancer-associated fibroblasts treated with cisplatin facilitates chemoresistance of lung adenocarcinoma through IL-11/IL-11R/STAT3 signaling pathway.

Cancer-associated fibroblasts (CAF) are recognized as one of the key determinants in the malignant progression of lung adenocarcinoma. And its contributions to chemoresistance acquisition of lung cancer has raised more and more attention. In our study, cancer associated fibroblasts treated with cisplatin conferred chemoresistance to lung cancer cells. Meanwhile, Interleukin-11(IL-11) was significantly up-regulated in the CAF stimulated by cisplatin. As confirmed in lung adenocarcinoma cells in vivo and in vitro, IL-11 could protect cancer cells from cisplatin-induced apoptosis and thus promote their chemoresistance. Furthermore, it was also observed that IL-11 induced STAT3 phosphorylation and increased anti-apoptotic protein Bcl-2 and Survivin expression in cancer cells. The effect could be abrogated by suppressing STAT3 phosphorylation or silencing IL-11Rα expression in cancer cells. In conclusion, chemotherapy-induced IL-11 upregulation in CAF promotes lung adenocarcinoma cell chemoresistance by activating IL-11R/STAT3 anti-apoptotic signaling pathway.

Hypoxia induced CCL28 promotes angiogenesis in lung adenocarcinoma by targeting CCR3 on endothelial cells.

Tumor hypoxia is one of the important features of lung adenocarcinoma. Chemokines might mediate the effects caused by tumor hypoxia. As confirmed in tumor tissue and serum of patients, CC chemokine 28 (CCL28) was the only hypoxia induced chemokine in lung adenocarcinoma cells. CCL28 could promote tube formation, migration and proliferation of endothelial cells. In addition, angiogenesis was promoted by CCL28 in the chick chorioallantoic membrane and matrigel implanted in dorsal back of athymic nude mice (CByJ.Cg-Foxn1(nu)/J). Tumors formed by lung adenocarcinoma cells with high expression of CCL28 grew faster and had a higher vascular density, whereas tumor formation rate of lung adenocarcinoma cells with CCL28 expression knockdown was quite low and had a lower vascular density. CCR3, receptor of CCL28, was highly expressed in vascular endothelial cells in lung adenocarcinoma when examining by immunohistochemistry. Further signaling pathways in endothelial cells, modulated by CCL28, were analyzed by Phosphorylation Antibody Array. CCL28/CCR3 signaling pathway could bypass that of VEGF/VEGFR on the levels of PI3K-Akt, p38 MAPK and PLC gamma. The effects could be neutralized by antibody against CCR3. In conclusion, CCL28, as a chemokine induced by tumor hypoxia, could promote angiogenesis in lung adenocarcinoma through targeting CCR3 on microvascular endothelial cells.

Endocrine vasculatures are preferable targets of an antitumor ineffective low dose of anti-VEGF therapy.

Anti-VEGF-based antiangiogenic drugs are designed to block tumor angiogenesis for treatment of cancer patients. However, anti-VEGF drugs produce off-tumor target effects on multiple tissues and organs and cause broad adverse effects. Here, we show that vasculatures in endocrine organs were more sensitive to anti-VEGF treatment than tumor vasculatures. In thyroid, adrenal glands, and pancreatic islets, systemic treatment with low doses of an anti-VEGF neutralizing antibody caused marked vascular regression, whereas tumor vessels remained unaffected. Additionally, a low dose of VEGF blockade significantly inhibited the formation of thyroid vascular fenestrae, leaving tumor vascular structures unchanged. Along with vascular structural changes, the low dose of VEGF blockade inhibited vascular perfusion and permeability in thyroid, but not in tumors. Prolonged treatment with the low-dose VEGF blockade caused hypertension and significantly decreased circulating levels of thyroid hormone free-T3 and -T4, leading to functional impairment of thyroid. These findings show that the fenestrated microvasculatures in endocrine organs are more sensitive than tumor vasculatures in response to systemic anti-VEGF drugs. Thus, our data support the notion that clinically nonbeneficial treatments with anti-VEGF drugs could potentially cause adverse effects.