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.

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.

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.

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.

Secreted frizzled related protein 1 modulates taxane resistance of human lung adenocarcinoma.

Taxanes, such as docetaxel and taxol, have been used as firstline chemotherapies in advanced lung adenocarcinoma (LAD), but limited responses to chemotherapy remain a major impediment in the clinic. Treatment with 5-azacytidine increases the sensitivity of SPC-A1/DTX cell line to taxanes. The results of DNA methylation microarray and cDNA array analysis indicate that DNA methylation contributes to the downregulation of secreted frizzled related protein 1 (SFRP1) in SPC-A1/DTX cells. Overexpression of SFRP1 reverses the chemoresistance of taxane-resistant LAD cell lines and enhances the in vivo sensitivity of taxane-resistant LAD cells to taxanes. Meanwhile, short hairpin RNA (shRNA)-mediated SFRP1 knockdown decreases the sensitivity of parental LAD cell lines to taxanes. Furthermore, FH535, a reversible Wnt signaling inhibitor, enhances the sensitivity of taxane-resistant LAD cells to taxanes. The level of SFRP1 in tumors of nonresponding patients is significantly lower than that in tumors of responders. Taken together, our results provide the direct evidence that SFRP1 is a clinically important determinant of taxanes resistance in human LAD cells, suggesting that SFRP1 might be a novel therapeutic target for the treatment of taxane-resistant LAD patients.

Quantitative assessment of the association between three polymorphisms in FAS and FASL gene and breast cancer risk.

FAS and FAS ligand (FASL) play crucial roles in apoptotic signaling, and deregulation of this pathway may facilitate carcinogenesis. Studies on the association between the FAS/FASL polymorphisms (FAS-1377G/A rs2234767, FAS-670A/G rs1800682, and FASL-844C/T rs763110) and breast cancer risk have reported inconsistent results. Therefore, to characterize the relationship between those polymorphisms and breast cancer risk, we undertook a meta-analysis of those studies. Several electronic databases were searched for articles on the FAS/FASL polymorphisms and breast cancer risk. The genotype data were extracted; pooled odds ratios (OR) with 95% confidence intervals (CIs) were used to estimate the strength of the association. Five studies were eligible for our meta-analysis. Overall, we observed significant associations of the FAS-1377G/A polymorphism with breast cancer susceptibility (AG vs. GG: OR = 1.15, 95% CI 1.02-1.30; AA vs. GG: OR = 1.39, 95% CI 1.12-1.72; AG/AA vs. GG: OR = 1.18, 95% CI, 1.16-1.32; A vs. G: OR = 1.16, 95% CI 1.06-1.26), but we did not observe significant association of the Fas-670A/G and FasL-844C/T polymorphisms with breast cancer risk. In the subgroup analysis, we observed that the FAS-1377G/A and FASL-844C/T polymorphisms were associated with breast cancer risk in Chinese but not Whites; we still did not observed association of the FAS-670A/G polymorphism with breast cancer risk. Our meta-analysis revealed that FAS-1377G>A polymorphism was associated with an increased risk of breast cancer. FASL-844C>T polymorphism might be associated with a reduced breast cancer risk in Chinese. However, FAS-670A/G had no any effect on breast carcinogenesis.

Risk of hypertension with regorafenib in cancer patients: a systematic review and meta-analysis.

BACKGROUND: Regorafenib is a novel multikinase inhibitor approved for use in metastatic colorectal cancer (mCRC) and locally advanced gastrointestinal stromal tumors (GISTs). Hypertension is one of the major adverse events of this agent, but to date the incidence and risk of hypertension with regorafenib have not been systematically investigated. We have conducted a systematic review and meta-analysis of published clinical trials to determine its overall incidence and risk. METHODS: PubMed, Web of Science and abstracts presented at the American Society of Clinical Oncology annual meetings were searched to identify relevant studies published up to September 9, 2013. Eligible studies were prospective phase II or III clinical trials using regorafenib in cancer patients with data on hypertension available. The incidence and relative risk (RR) of hypertension were calculated using a random-effects model. RESULTS: Data from a total of 1,069 patients (regorafenib n = 750; controls n = 319) from five clinical trials were included for analysis. The overall incidence of all-grade and high-grade hypertension were 44.4 % [95 % confidence interval (CI) 30.8-59.0 %) and 12.5 % (95 % CI 5.2-27.1 %), respectively. The use of regorafenib in cancer patients was associated with a significantly increased risk of all-grade (RR 3.76, 95 % CI 2.35-5.99) and high-grade (RR, 8.39, 95 % CI 3.10-22.71) hypertension. The risk might vary with tumor types (P = 0.000). CONCLUSIONS: Patients with cancer receiving regorafenib have a significantly higher risk of developing hypertension. Close monitoring and appropriate management of this hypertension are strongly recommended.

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.

Pericytes recruited by CCL28 promote vascular normalization after anti-angiogenesis therapy through RA/RXRA/ANGPT1 pathway in lung adenocarcinoma.

BACKGROUND: It has been proposed that anti-angiogenesis therapy could induce tumor "vascular normalization" and further enhance the efficacy of chemotherapy, radiotherapy, target therapy, and immunotherapy for nearly twenty years. However, the detailed molecular mechanism of this phenomenon is still obscure. METHOD: Overexpression and knockout of CCL28 in human lung adenocarcinoma cell line A549 and murine lung adenocarcinoma cell line LLC, respectively, were utilized to establish mouse models. Single-cell sequencing was performed to analyze the proportion of different cell clusters and metabolic changes in the tumor microenvironment (TME). Immunofluorescence and multiplex immunohistochemistry were conducted in murine tumor tissues and clinical biopsy samples to assess the percentage of pericytes coverage. Primary pericytes were isolated from lung adenocarcinoma tumor tissues using magnetic-activated cell sorting (MACS). These pericytes were then treated with recombinant human CCL28 protein, followed by transwell migration assays and RNA sequencing analysis. Changes in the secretome and metabolome were examined, and verification of retinoic acid metabolism alterations in pericytes was conducted using quantitative real-time PCR, western blotting, and LC-MS technology. Chromatin immunoprecipitation followed by quantitative PCR (ChIP-qPCR) was employed to validate the transcriptional regulatory ability and affinity of RXRα to specific sites at the ANGPT1 promoter. RESULTS: Our study showed that after undergoing anti-angiogenesis treatment, the tumor exhibited a state of ischemia and hypoxia, leading to an upregulation in the expression of CCL28 in hypoxic lung adenocarcinoma cells by the hypoxia-sensitive transcription factor CEBPB. Increased CCL28 could promote tumor vascular normalization through recruiting and metabolic reprogramming pericytes in the tumor microenvironment. Mechanistically, CCL28 modified the retinoic acid (RA) metabolism and increased ANGPT1 expression via RXRα in pericytes, thereby enhancing the stability of endothelial cells. CONCLUSION: We reported the details of the molecular mechanisms of "vascular normalization" after anti-angiogenesis therapy for the first time. Our work might provide a prospective molecular marker for guiding the clinical arrangement of combination therapy between anti-angiogenesis treatment and other therapies.

Chemotherapy-induced high expression of IL23A enhances efficacy of anti-PD-1 therapy in TNBC by co-activating the PI3K-AKT signaling pathway of CTLs.

Treatment of advanced triple-negative breast cancer (TNBC) is a great challenge in clinical practice. The immune checkpoints are a category of immunosuppressive molecules that cancer could hijack and impede anti-tumor immunity. Targeting immune checkpoints, such as anti-programmed cell death 1 (PD-1) therapy, is a promising therapeutic strategy in TNBC. The efficacy and safety of PD-1 monoclonal antibody (mAb) with chemotherapy have been validated in TNBC patients. However, the precise mechanisms underlying the synergistic effect of chemotherapy and anti-PD-1 therapy have not been elucidated, causing the TNBC patients that might benefit from this combination regimen not to be well selected. In the present work, we found that IL-23, an immunological cytokine, is significantly upregulated after chemotherapy in TNBC cells and plays a vital role in enhancing the anti-tumor immune response of cytotoxic T cells (CTLs), especially in combination with PD-1 mAb. In addition, the combination of IL-23 and PD-1 mAb could synergistically inhibit the expression of Phosphoinositide-3-Kinase Regulatory Subunit 1 (PIK3R1), which is a regulatory subunit of PI3K and inhibit p110 activity, and promote phosphorylation of AKT in TNBC-specific CTLs. Our findings might provide a molecular marker that could be used to predict the effects of combination chemotherapy therapy and PD-1 mAb in TNBC.

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.

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.

The relationship between RGS5 expression and cancer differentiation and metastasis in non-small cell lung cancer.

BACKGROUND: Regulator of G-protein signaling 5 (RGS5), a tissue-specific signal regulating molecular, plays important roles in the development of vasculature. Recently, we have found that the mRNA level of RGS5 was oppositely related with tumor metastasis in non-small cell lung cancer (NSCLC). However, the distribution of RGS5 in NSCLC and its significance need further study. We therefore investigated the expression of RGS5 in NSCLC, as well as its relationship with clinicopathologic parameters. METHODS: Tumor tissues from 51 NSCLC patients were analyzed and expression of RGS5 in tumor tissues was examined by immunohistochemistry. Chi-square test (or Fisher's exact test), Breslow test and multivariate Cox regression model were performed for statistical analysis. RESULTS: RGS5 were highly expressed in 47% (24/51) of NSCLC specimens. Expression of RGS5 was associated with tumor cell differentiation in NSCLC and low expression of RGS5 was strongly associated with cancer vasculature invasion and lymph node metastasis in NSCLC. Patients with high RGS5 expression in NSCLC had a prolonged progression free survival (15.0 months (95%CI: 6.1-23.9) vs. 6.0 months (95%CI: 1.3-10.7), P = 0.030). CONCLUSION: RGS5 might be involved in cancer differentiation and metastasis in NSCLC. And it might be a candidate prognostic marker for PFS in NSCLC.

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.

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.

Preconditioning chemotherapy with paclitaxel and cisplatin enhances the antitumor activity of cytokine induced-killer cells in a murine lung carcinoma model.

Adoptive cell therapy involving the use of ex vivo generated cytokine-induced killer cells (CIKs) provides a promising approach to immunotherapy. However, the therapeutic activity of CIKs is limited by the immunosuppressive factors active in the host. It has become increasingly apparent that manipulation of the recipient immune system with the preconditioning regimen is essential to guarantee the antitumor effect of subsequent adoptive cell therapy. In our study, paclitaxel (PTX) and cisplatin (DDP) were used as preconditioning drugs combined with CIKs to illustrate the potential mechanisms underlying the synergic antitumor effect against Lewis lung cancer cells in vitro and in vivo. We found that 3LL cells displayed an increased sensitization to CIKs-induced lysis after treatment with PTX or DDP in vitro. Significant inhibition of tumor growth was observed in mice treated with combinatorial chemo-immunotherapy with respect to untreated or single regimen treated ones. Prior chemotherapy markedly enhanced the intratumoral accumulation of CD3(+) T lymphocytes and the homing of CIKs to the spleen and tumor. Moreover, the frequencies of intratumoral and splenic regulatory T cells (Tregs) were significantly decreased after chemotherapy pretreatment. Our findings provide a new rationale for combining immunotherapy and chemotherapy to induce a synergistic antitumor response in patients with lung cancer.

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.

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.

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.

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.