RESUMO
BACKGROUND: Hypoxic tumors are known to be highly resistant to radiotherapy and cause poor prognosis in non-small cell lung cancer (NSCLC) patients. CKD-516, a novel vascular disrupting agent (VDA), mainly affects blood vessels in the central area of the tumor and blocks tubulin polymerization, thereby destroying the aberrant tumor vasculature with a rapid decrease in blood, resulting in rapid tumor cell death. Therefore, we evaluated the anti-tumor efficacy of CKD-516 in combination with irradiation (IR) and examined tumor necrosis, delayed tumor growth, and expression of proteins involved in hypoxia and angiogenesis in this study. METHODS: A xenograft mouse model of lung squamous cell carcinoma was established, and the tumor was exposed to IR 5 days per week. CKD-516 was administered with two treatment schedules (day 1 or days 1 and 5) 1 h after IR. After treatment, tumor tissues were stained with hematoxylin and eosin, and pimonidazole. HIF-1α, Glut-1, VEGF, CD31, and Ki-67 expression levels were evaluated using immunohistochemical staining. RESULTS: Short-term treatment with IR alone and CKD-516 + IR (d1) significantly reduced tumor volume (p = 0.006 and p = 0.048, respectively). Treatment with CKD-516 + IR (d1 and d1, 5) resulted in a marked reduction in the number of blood vessels (p < 0.005). More specifically, CKD-516 + IR (d1) caused the most extensive tumor necrosis, which resulted in a significantly large hypoxic area (p = 0.02) and decreased HIF-1α, Glut-1, VEGF, and Ki-67 expression. Long-term administration of CKD-516 + IR reduced tumor volume and delayed tumor growth. This combination also greatly reduced the number of blood vessels (p = 0.0006) and significantly enhanced tumor necrosis (p = 0.004). CKD-516 + IR significantly increased HIF-1α expression (p = 0.0047), but significantly reduced VEGF expression (p = 0.0046). CONCLUSIONS: Taken together, our data show that when used in combination, CKD-516 and IR can significantly enhance anti-tumor efficacy compared to monotherapy in lung cancer xenograft mice.
Assuntos
Benzofenonas/administração & dosagem , Carcinoma Pulmonar de Células não Pequenas/terapia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Neoplasias Pulmonares/terapia , Valina/análogos & derivados , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Benzofenonas/farmacologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Linhagem Celular Tumoral , Fracionamento da Dose de Radiação , Esquema de Medicação , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Transportador de Glucose Tipo 1/metabolismo , Humanos , Antígeno Ki-67/metabolismo , Neoplasias Pulmonares/metabolismo , Masculino , Camundongos , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Radioterapia , Resultado do Tratamento , Valina/administração & dosagem , Valina/farmacologiaRESUMO
BACKGROUND/AIM: LY2835219 (LY), a novel CDK4/6 inhibitor, prevents cell proliferation through G1 arrest. Docetaxel (DTX) and paclitaxel (PTX) are cytotoxic drugs targeting tubulin-mediated apoptotic cell death via G2/M arrest. We evaluated the antitumor effects of DTX/PTX and LY individually and in combination in lung adenocarcinoma cells with or without KRAS mutations and xenograft mice harboring KRAS mutations. MATERIALS AND METHODS: We investigated in vitro/in vivo changes in signaling molecules and analyzed cell proliferation, cycle, and apoptosis via flow cytometry and western blotting. RESULTS: LY cytotoxicity was dose-dependent and varied with KRAS mutation status. DTXâLY showed synergistic cytotoxicity regardless of KRAS mutation. Furthermore, the synergistic effect of PTXâLY was significantly greater than that of PTX+LY. DTXâLY remarkably reduced the number of G0/G1 cells and increased the number of G2/M arrested cells, resulting in an increase in apoptosis and subG1 cells. CONCLUSION: DTXâLY has synergistic antitumor effect in lung cancer cells and xenograft mice regardless of KRAS mutation.
Assuntos
Quinase 4 Dependente de Ciclina/antagonistas & inibidores , Quinase 6 Dependente de Ciclina/antagonistas & inibidores , Neoplasias Pulmonares/tratamento farmacológico , Proteínas Proto-Oncogênicas p21(ras)/genética , Taxoides/farmacologia , Aminopiridinas/farmacologia , Aminopiridinas/uso terapêutico , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Benzimidazóis/farmacologia , Benzimidazóis/uso terapêutico , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sinergismo Farmacológico , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos , Mutação , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Transdução de Sinais/efeitos dos fármacos , Taxoides/uso terapêutico , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: We screened resected tumor tissues from patients with lung cancer for EGFR mutations, ALK rearrangements, and rearranged during transfection (RET) gene variants (including RET rearrangements and the Kinesin Family Member 5B (KIF5B)-RET fusion gene) using various methods including reverse transcription polymerase chain reaction (RT-PCR), transcript assays, fluorescence in situ hybridization (FISH), and immunohistochemistry (IHC). We also examined the protein expression of associated downstream signaling molecules to assess the effect of these variants on patient outcome. METHOD: We constructed a tissue microarray (TMA) comprising 581 resected tumor tissues from patients with lung adenocarcinoma and analyzed the microarray by both FISH (using RET break-apart and KIF5B-RET SY translocation probes) and a commercial RET transcript assay. We evaluated the expression of RET and RET-related signaling molecules, including p-AKT and p-ERK, by TMA -based IHC staining. RESULTS: Among the 581 specimens, 51 (8.8%) specimens harbored RET rearrangements, including 12 cases (2.1%) carrying a KIF5B-RET fusion gene. Surprisingly, RET expression was lower in KIF5B-RET fusion gene-positive than in RET wild-type specimens. We detected activating EGFR mutations in 11 (21.6%) of the 51 RET variant-positive specimens. Among the KIF5B-RET fusion gene-positive specimens, p-ERK expression was significantly lower in the EGFR mutation subgroup showing RET expression than in the EGFR mutation subgroup that did not express RET. Similarly, the RET rearrangement group showed significant variation in the expression level of p-AKT (Pâ¯=â¯0.028) and p-ERK, whose expression remarkably increased in specimens not expressing RET. The expression of p-ERK markedly increased in the RET rearrangement group regardless of RET expression. CONCLUSION: This result suggests that a combination of RET and ERK inhibitors may be an effective treatment strategy for lung adenocarcinoma patients harboring RET variants.