Kunyu Yang

Long-Term Clinical Outcome of Intensity-Modulated Radiotherapy for Inoperable Non-Small Cell Lung Cancer: The MD Anderson Experience

PURPOSE In 2007, we published our initial experience in treating inoperable non-small-cell lung cancer (NSCLC) with intensity-modulated radiation therapy (IMRT). The current report is an update of that experience with long-term follow-up. METHODS AND MATERIALS Patients in this retrospective review were 165 patients who began definitive radiotherapy, with or without chemotherapy, for newly diagnosed, pathologically confirmed NSCLC to a dose of ≥60 Gy from 2005 to 2006. Early and late toxicities assessed included treatment-related pneumonitis (TRP), pulmonary fibrosis, esophagitis, and esophageal stricture, scored mainly according to the Common Terminology Criteria for Adverse Events 3.0. Other variables monitored were radiation-associated dermatitis and changes in body weight and Karnofsky performance status. The Kaplan-Meier method was used to compute survival and freedom from radiation-related acute and late toxicities as a function of time. RESULTS Most patients (89%) had Stage III to IV disease. The median radiation dose was 66 Gy given in 33 fractions (range, 60-76 Gy, 1.8-2.3 Gy per fraction). Median overall survival time was 1.8 years; the 2-year and 3-year overall survival rates were 46% and 30%. Rates of Grade ≥3 maximum TRP (TRP(max)) were 11% at 6 months and 14% at 12 months. At 18 months, 86% of patients had developed Grade ≥1 maximum pulmonary fibrosis (pulmonary fibrosis(max)) and 7% Grade ≥2 pulmonary fibrosis(max). The median times to maximum esophagitis (esophagitis(max)) were 3 weeks (range, 1-13 weeks) for Grade 2 and 6 weeks (range, 3-13 weeks) for Grade 3. A higher percentage of patients who experienced Grade 3 esophagitis(max) later developed Grade 2 to 3 esophageal stricture. CONCLUSIONS In our experience, using IMRT to treat NSCLC leads to low rates of pulmonary and esophageal toxicity, and favorable clinical outcomes in terms of survival.

Matrix-Metallo-Proteinases and their tissue inhibitors in radiation-induced lung injury

Purpose: Remodeling of extracellular matrix (ECM) after lung damage depends on collagen degrading Matrix-Metallo-Proteinases (MMP) and their endogenous inhibitors (Tissue-Inhibitors of Metallo-Proteinases, TIMP). Transforming growth factor (TGF)-β1 has been implicated in the pathogenesis of radiation-induced lung fibrosis upon its effects on fibroblast proliferation and collagen synthesis. Lung cancer patients have often elevated TGF-β1 plasma levels as a result of increased TGF-β1 expression in their tumours. On this background, we investigated the effect of irradiation on the MMP/TIMP system in the lung tissue of normal and transgenic TGF-β1 mice, in which TGF-β1 is overexpressed in the liver resulting in high TGF-β1 plasma levels. Material and methods: Transgenic (TG) and wild-type (WT) mice underwent thoracic irradiation with 12 Gy or sham-irradiation. For each study group (TG 12 Gy; TG 0 Gy; WT 12 Gy; WT 0 Gy) 8 mice were sacrificed at 4 and 8 weeks after (sham-) irradiation. The TGF-β1, TIMP-1/-2/-3 expression in the lung tissue was quantified by Western blot; the MMP-2 and MMP-9 activity was analysed by zymography. The cellular origin of the MMP and TIMP was localised by immunohistochemistry. Results: Irradiation had no influence on the TIMP-1/-2/-3, but increased significantly the MMP-2 /-9 expression. In the lung tissue of TG mice the TIMP-1/-2/-3 expression was elevated, the MMP-9 activity was decreased. The immunhistochemical study showed that parenchymal and inflammatory cells express these MMP/TIMP. Conclusion: Our results provide evidence that the overexpression of MMP-2 and MMP-9 is involved in the inflammatory response of radiation-induced lung injury. MMP-2 and MMP-9 are known to degrade collagen IV of basement membranes, therefore affecting the structural integrity of lung tissue. In contrast, in lung tissue of TG mice the TIMP-1/-2/-3 expression was up-regulated and the MMP-9 activity was diminished, thereby decreasing possibly the ECM degradation leading to lung fibrosis.

VEGF-PKD1-HDAC7 signaling promotes endothelial progenitor cell migration and tube formation.

Histone acetylation/deacetylation is a key mechanism for regulating transcription, which plays an important role in the control of gene expression, tissue growth, and development. In particular, histone deacetylase 7 (HDAC7), a member of class IIa HDACs, is crucial in maintaining vascular integrity. Endothelial progenitor cells (EPCs) play an important role in angiogenesis. However, whether HDAC7 plays a role in the processes of EPCs angiogenesis remains unclear. Migration and tube formation were the two major components of EPC angiogenesis. In this study, we show for the first time that HDAC7 silencing weakened the migration and tube formation abilities of EPCs. VEGF-A induced an increase of phospho-HDAC7 and its nuclear export in a time-dependent manner, which could be partly inhibited by protein kinase D1 (PKD1) inhibitor, but not by the PI3K inhibitor or the MEK inhibitor. Our results showed that EPCs involved in the angiogenesis might be controlled by VEGF-PKD1-HDAC7 axis, which regulates the EPCs angiogenesis by PKD1, but not the ERK and PI3K pathway.

Optimization of parameters for preparation of docetaxel-loaded PLGA nanoparticles by nanoprecipitation method

The purpose of this study was to develop docetaxel-poly (lactide-co-glycolide) (PLGA) loaded nanoparticles by using nanoprecipitation method and optimize the relative parameters to obtain nanoparticles with higher encapsulation efficiency and smaller size. The physicochemical characteristics of nanoparticles were studied. The optimized parameters were as follows: the oil phase was mixture of acetone and ethanol, concentration of tocopheryl polyethylene glycol succinate (TPGS) was 0.2%, the ratio of oil phase to water phase was 1:5, and the theoretical drug concentration was 5%. The optimized nanoparticles were spherical with size between 130 and 150 nm. The encapsulation efficiency was (40.83±2.1)%. The in vitro release exhibited biphasic pattern. The results indicate that docetaxel-PLGA nanoparticles were successfully fabricated and may be used as the novel vehicles for docetaxel, which would replace Taxotere® and play great roles in future.SummaryThe purpose of this study was to develop docetaxel-poly (lactide-co-glycolide) (PLGA) loaded nanoparticles by using nanoprecipitation method and optimize the relative parameters to obtain nanoparticles with higher encapsulation efficiency and smaller size. The physicochemical characteristics of nanoparticles were studied. The optimized parameters were as follows: the oil phase was mixture of acetone and ethanol, concentration of tocopheryl polyethylene glycol succinate (TPGS) was 0.2%, the ratio of oil phase to water phase was 1:5, and the theoretical drug concentration was 5%. The optimized nanoparticles were spherical with size between 130 and 150 nm. The encapsulation efficiency was (40.83±2.1)%. The in vitro release exhibited biphasic pattern. The results indicate that docetaxel-PLGA nanoparticles were successfully fabricated and may be used as the novel vehicles for docetaxel, which would replace Taxotere® and play great roles in future.

Gefitinib-Induced Hepatotoxicity in Patients Treated for Non-Small Cell Lung Cancer

Background: Although epidermal growth factor receptor (EGFR)-specific tyrosine kinase inhibitors (TKIs) are widely used in the management of advanced non-small cell lung cancer (NSCLC), gefitinib-induced hepatotoxicity has been underappreciated and rarely reported. Case Report: The medical records of 92 NSCLC patients, who were admitted to our cancer center in the past 5 years, were reviewed retrospectively. All patients received treatment with gefitinib (250 mg/day), during which liver function was monitored. Of the 92 NSCLC patients, 6 (6.5%) developed mild to moderate hepatotoxicity during gefitinib treatment. The time of onset of hepatotoxicity ranged from 7 days to 6 months after gefitinib administration. 1 patient (1.1%) suffered from grade 2 hepatotoxicity, and gradually recovered her normal liver function after reduction of the gefitinib dose. The other 5 patients with grade 1 hepatic impairment tolerated gefitinib well without requiring dose reductions or drug cessation. Conclusion: Gefitinib-induced hepatotoxicity is not uncommon. Although the extent of this toxicity is generally mild in nature and most patients tolerate gefitinib well, meticulous monitoring is mandatory to avoid severe hepatic impairment.

Antitumor activity of SAHA, a novel histone deacetylase inhibitor, against murine B cell lymphoma A20 cells in vitro and in vivo

Suberoylanilide hydroxamic acid (SAHA; vorinostat), the second generation of histone deacetylase (HDAC) inhibitor, has been approved for the treatment of cutaneous manifestations of cutaneous T cell lymphoma (CTCL). It has also shown its anticancer activity over a large range of other hematological and solid malignancies, but few studies have been reported in B cell lymphoma. In this study, we aimed to investigate the antitumor activity of SAHA on murine B cell lymphoma cell line A20 cells. We treated A20 cells with different concentrations of SAHA. The effect of SAHA on the proliferation of A20 cells was studied by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium (MTT) assay in vitro; the anti-proliferation activity in vivo was evaluated by proliferating cell nuclear antigen (PCNA) of xenograft tumor tissues through immunocytochemical staining. Apoptosis were detected by Hoechst 33258 staining and Annexin V/propidium iodide (PI) double-labeled cytometry in vitro. The effect of SAHA on cell cycle of A20 cells was studied by a propidium iodide method. Autophagic cell death induced by SAHA was confirmed by transmission electron microscopy (TEM). Angiogenesis marker (CD31) was measured by immunocytochemical staining to investigate the anti-angiogenic effect of SAHA. Western blot was used to detect the expression of signaling pathway factors (phospho-AKT, phospho-ERK, AKT, ERK, Nur77, HIF-1α, and VEGF). Our results showed that SAHA inhibited the proliferation of A20 cells in a time- and dose-dependent manner, induced cell apoptosis and G0/G1 phase arrest of cell cycle, promoted autophagic cell death, and suppressed tumor progress in NCI-A20 cells nude mice xenograft model in vivo. SAHA decreased the activation of AKT (phospho-AKT: p-AKT) and ERK1/2 (phospho-ERK: p-ERK) proteins and inhibited the expression of pro-angiogenic factors (VEGF and HIF-1α), downregulated its downstream signaling factor (Nur77), which might be contributed to the antitumor mechanisms of SAHA.

Tumor Ablation and Therapeutic Immunity Induction by an Injectable Peptide Hydrogel

Immunosuppressive tumor microenvironments (TMEs) create tremendous obstacles for an effective cancer therapy. Herein, we developed a melittin-RADA32 hybrid peptide hydrogel loaded with doxorubicin (DOX) for a potent chemoimmunotherapy against melanoma through the active regulation of TMEs. The formed melittin-RADA32-DOX (MRD) hydrogel has an interweaving nanofiber structure and exhibits excellent biocompatibility, controlled drug release properties both in vitro and in vivo, and an enhanced killing effect to melanoma cells. A single-dose injection of MRD hydrogel retarded the growth of primary melanoma tumors by more than 95% due to loaded melittin and DOX, with concomitant recruitment of activated natural killer cells in the tumors. Furthermore, MRD hydrogel can activate dendritic cells of draining lymph nodes, specifically deplete M2-like tumor-associated macrophages (TAMs), and produce active, cytotoxic T cells to further defend the cells against remaining tumors, providing potent anticancer efficacy against subcutaneous and metastatic tumors in vivo. Multidose injection of MRD hydrogel eliminated 50% of the primary tumors and provided a strong immunological memory effect against tumor rechallenge after eradication of the initial tumors. Owing to its abilities to perform controlled drug release, regulate innate immune cells, deplete M2-like TAMs, direct anticancer and immune-stimulating capabilities, and reshape immunosuppressive TMEs, MRD hydrogel may serve as a powerful tool for anticancer applications.

RNAi silencing targeting RNF8 enhances radiosensitivity of a non-small cell lung cancer cell line A549

Abstract Purpose: The E3 ubiquitin ligase RNF8 regulates the accumulation or removal of a number of proteins at DNA lesions, thereby playing a critically important role in DNA damage response. The present study investigated the possibility of using RNF8 as a new target in the radiation treatment of human non-small cell lung cancer. Methods and materials: We used RNA interference technology to silence the expression of RNF8 in A549 cells, and then detected the radiation response by colony forming assays. DNA repair was monitored by γ-H2AX foci formation after RNF8 depletion. Expression of Ku70 and Rad51 were assessed by immunofluorescent staining and Western blotting. Cell cycle and apoptosis were measured by flow cytometry assays. Results: After lentivirus-mediated siRNA transfection, expression of RNF8 in A549 cells downregulated which led to an increased radiosensitivity and impaired DNA repair. RNF8 knockdown did not affect Ku70 expression, however, Rad51, a key player in homologous recombination (HR) repair, was abrogated at sites of DNA damage. Furthermore, we observed an extended G2/M arrest and an increased induction of apoptosis after ionizing radiation in the absence of RNF8. Conclusions: RNF8 silencing effectively downregulates Rad51 therefore maybe impairing HR repair, and prolongs the G2/M accumulation as well as cell apoptosis upon radiation, which all suggest an enhanced radiosensitivity on A549 cells.

CDP138 silencing inhibits TGF- β /Smad signaling to impair radioresistance and metastasis via GDF15 in lung cancer

CDP138, a CDK5 binding partner, regulates cell proliferation and migration. However, the mechanisms by which CDP138 functions in these processes remain unclear. In this study, we show that CDP138 is frequently overexpressed and that high levels of CDP138 are correlated with lymph node metastasis in lung cancer. Furthermore, we provide evidence that CDP138-depleted lung cancer cells exhibit enhanced radiosensitivity as well as reduced migration and invasion. Mechanistically, we identify GDF15, a member of the TGF-β superfamily, as a key downstream effector of CDP138. CDP138 silencing attenuates TGF-β/Smad signaling activation at least in part through the downregulation of GDF15. More importantly, the observed phenotypes caused by CDP138 knockdown are partially dependent on GDF15 inhibition. Together, our findings demonstrate that CDP138 positively modulates the TGF-β/Smad signaling pathway via GDF15 to promote radioresistance and metastasis, suggesting CDP138 as a potential oncogenic biomarker and a promising therapeutic target in the treatment of lung cancer.

Cardamonin induces ROS-mediated G2/M phase arrest and apoptosis through inhibition of NF- κ B pathway in nasopharyngeal carcinoma

Cardamonin has been demonstrated to have an inhibitory effect in many cancers, but its underlying mechanism remains elusive. Here, we studied, for the first time, the mechanism of cardamonin-induced nasopharyngeal carcinoma cell death both in vitro and in vivo. In our study, we showed that cardamonin inhibited cancer cell growth by inducing G2/M phase cell cycle arrest and apoptosis via accumulation of ROS. NF-κB activation was involved in breaking cellular redox homeostasis. Therefore, our results provided new insight into the mechanism of the antitumor effect of cardamonin, supporting cardamonin as a prospective therapeutic drug in nasopharyngeal carcinoma by modulating intracellular redox balance.