phenanthrenes and Adenocarcinoma-of-Lung

The epidermal growth factor receptor‑tyrosine kinase inhibitor (EGFR‑TKI), gefitinib, is used widely to treat non‑small cell lung cancer (NSCLC) with EGFR‑activating mutations. Unfortunately, the acquired drug resistance promoted by epithelial‑mesenchymal transition (EMT) markedly limits the clinical effects and remains a major barrier to a cure. Our previous isobaric tags for relative and absolute quantitation‑based proteomics analysis revealed that the E‑cadherin protein level was markedly upregulated by triptolide (TP). The present study aimed to determine whether TP reverses the gefitinib resistance of human lung cancer cells by regulating EMT. It was revealed that TP combined with gefitinib synergistically inhibited the migration and invasion of lung adenocarcinoma cell line A549; the combination treatment had a significantly better outcome than that of TP and gefitinib alone. Moreover, TP effectively increased the sensitivity of drug resistant A549 cells to gefitinib by upregulating E‑cadherin protein expression and downregulating the MMP9, SNAIL, and vimentin expression levels. The dysregulated E‑cadherin expression of gefitinib‑sensitive cells induced gefitinib resistance, which could be overcome by TP. Finally, TP combined with gefitinib significantly inhibited the growth of xenograft tumors induced using gefitinib‑resistant A549 cells, which was associated with EMT reversal and E‑cadherin signaling activation in vivo. The present results indicated that the combination of TP and TKIs may be a promising therapeutic strategy to treat patients with NSCLCs harboring EGFR mutations.

Topics: A549 Cells; Adenocarcinoma of Lung; Animals; Antigens, CD; Cadherins; Cell Proliferation; Cell Survival; Diterpenes; Drug Resistance, Neoplasm; Drug Synergism; Epithelial-Mesenchymal Transition; Epoxy Compounds; Gefitinib; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; Male; Mice; Phenanthrenes; Xenograft Model Antitumor Assays

Paclitaxel (or Taxol®) is a first-line chemotherapeutic drug for the treatment of non-small cell lung cancer; however, resistance to the drug is an important factor, which influences the outcome of chemotherapy. The present study aimed to investigate the role of triptolide (TPL) in reversing Taxol‑resistant human lung adenocarcinoma and to elucidate the underlying molecular mechanism of resistance reversal mediated by TPL. It was hypothesized that this experimental approach would assist in solving the problem of chemotherapeutic resistance in non‑small cell lung cancer, thereby improving the clinical outcomes. The human Taxol‑resistant lung adenocarcinoma cell line, A549/Taxol, was established. The resistance index of the cell line was calculated, according to the half maximal inhibitory concentration (IC50) of A549/Taxol IC50 of A549, to be 51.87. The levels of apoptosis and the cell cycle in the A549/Taxol cell line were assessed to confirm the effects of TPL at three different concentrations (0.03, 0.3 and 3 µmol/l) and treatment durations (2, 4, 6 and 12 h) by flow cytometric analysis, and the inhibition of the NF‑κB signaling pathway and the expression of NF‑κB‑regulated drug‑resistant proteins were determined by immunofluorescence and western blotting, respectively. The administration of TPL promoted cell apoptosis in the A549/Taxol lung adenocarcinoma Taxol‑resistant cell line and also promoted cell cycle regulation. The drug was also able to elicit a reversal of the drug resistance. TPL inhibited the nuclear factor‑κB (NF‑κB) signaling pathway and the expression of NF‑κB‑regulated drug‑resistant genes, including those for FLICE‑like inhibitory protein, X‑linked inhibitor of apoptosis protein, Bcl‑2, Bcl‑xL and cyclo‑oxygenase‑2. TPL exerted a marked drug‑resistance‑reversal effect on human lung adenocarcinoma Taxol resistance, and the effect was revealed to be dose‑ and time‑dependent. In conclusion, TPL exerted its role in the process of resistance reversal by inhibiting the NF‑κB signaling pathway, and the transcription and expression of NF-κB-regulated drug-resistant genes.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Apoptosis; Cell Cycle Checkpoints; Cell Line, Tumor; Diterpenes; Dose-Response Relationship, Drug; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Epoxy Compounds; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; Neoplasm Proteins; NF-kappa B; Paclitaxel; Phenanthrenes; S Phase; Signal Transduction; Time Factors

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.

Topics: A549 Cells; Adenocarcinoma; Adenocarcinoma of Lung; Animals; Antineoplastic Agents; Cancer-Associated Fibroblasts; Cell Communication; Cell Line, Tumor; Cisplatin; Drug Resistance, Neoplasm; Female; Gene Expression Regulation, Neoplastic; Humans; Interleukin-11; Lung Neoplasms; Mice; Mice, Inbred BALB C; Mice, Nude; Phenanthrenes; Phosphorylation; Primary Cell Culture; Receptors, Interleukin-11; RNA, Small Interfering; Signal Transduction; STAT3 Transcription Factor; Survival Analysis; Xenograft Model Antitumor Assays

Lung cancer is the leading cause of cancer death worldwide. Recently, two plant-derived drugs triptolide (TP) and hydroxycamptothecin (HCPT) both have shown broad-spectrum anticancer activities. Our previous study documented that combination treatment with these two drugs acted more effectively than mono-therapy, however, the molecular basis underlying the synergistic cytotoxicity remains poorly understood. In this study, we aimed to clarify the molecular mechanism of TP/HCPT anticancer effect in A549 lung adenocarcinoma cells, by investigating the involvement of phosphatase 2A (PP2A) and PP2A-regulated mitogen-activated protein kinases (MAPKs) and Akt signaling pathways. The results showed that TP and HCPT synergistically exerted cytotoxicity in the growth of A549 cells. Combinatorial TP/HCPT treatment significantly enhanced the activation of caspase-3 and -9, Bax/Bcl-2 ratio, release of cytochrome c from mitochondrial and subsequent apoptosis. While the Akt survival pathway was inhibited, ERK and p38 MAPKs were dramatically activated. Furthermore, the activity of PP2A was significantly augmented. Regulation of p38, ERK and Akt by PP2A was demonstrated, by using a specific PP2A inhibitor okadaic acid (OA). Finally, pharmacological inhibitors OA, SB203580, SP600125 and PD98059 confirm the role of PP2A and its substrates ERK, p38 MAPK and Akt in mediating TP/HCPT-induced apoptosis. Taken together, this study provides the first evidence for a synergistic TP/HCPT anticancer activity in A549 cells and also supports a critical role of PP2A and PP2A-regulated signaling pathways, providing new insight into the mode of action of TP/HCPT in cancer therapy.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Calcineurin; Camptothecin; Cell Line, Tumor; Diterpenes; Drug Synergism; Epoxy Compounds; Extracellular Signal-Regulated MAP Kinases; Humans; Irinotecan; Lung Neoplasms; p38 Mitogen-Activated Protein Kinases; Phenanthrenes; Proto-Oncogene Proteins c-akt; Signal Transduction

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) show promising therapeutic effects in patients with advanced non-small cell lung cancer (NSCLC). However, despite an initial response to TKIs treatment among responsive patients, most inevitably acquire resistance after a progression-free period of about 10 months. The percentage of T790M in TKI acquired-resistant patients in most studies is around 50%. The aim of this study is to assess the effects of the sequential administration of triptolide and geftinib on cell proliferation and apoptosis of lung adenocarcinoma cell H1975.. A MTT assay was used to measure cell proliferation. The potency of the sequential administration of triptolide and geftinib were determined by isobolograms and combination index (CI). Cell apoptosis and cycle distribution were detected by flow cytometry. The Hoechst 33258 method was used to observe the apoptotic morphology. Chemical colorimetric luminescence was used to measure the caspase activity.. The results of isobolograms and CI showed that the sequential administration of triptolide following geftinib remarkably inhibited cell proliferation and cell apoptosis compared with other sequential administration models. The cycle distribution results indicated that sequential triptolide administration following geftinib blocked the cells in the G2/M phase but not in the G0/G1 phase. The activation of the Caspase-9/Caspase-3 cascade was mainly involved in the apoptotic pathway of lung adenocarcinoma cell H1975 in all sequential administration models.. The triptolide administration following geftinib might be a new therapeutic strategy for lung cancer with T790M mutation after having EGFR-TKIs resistance.
.. 背景与目的 表皮生长因子受体（epidermal growth factor receptor, EGFR）酪氨酸激酶抑制剂（tyrosine kinase inhibitors, TKIs）被用于治疗进展性晚期非小细胞肺癌（non-small cell lung cancer, NSCLC），然而最初接受TKIs治疗有反应的患者，大都会在10个月左右出现获得性耐药。报告称EGFR基因T790M的突变是产生获得性耐药的主要原因，比例约占50%。本研究旨在探索雷公藤甲素（triptolide, TP）和吉非替尼序贯应用对肺腺癌细胞H1975细胞增殖和凋亡通路的作用。方法 MTT法检测细胞的增殖。等效线图法和联合指数（combination index, CI）法评估雷公藤甲素和吉非替尼序贯作用的效价。流式细胞术检测细胞凋亡和周期分布，Hoechest 33258染色法检测凋亡形态。化学比色发光法检测Caspases的活性。结果 等效线图法和联合指数法均显示雷公藤甲素序贯吉非替尼组较其他序贯作用组明显抑制了细胞增殖，增加了细胞的凋亡。细胞周期分布实验结果显示与吉非替尼序贯雷公藤甲素组主要把细胞抑制在G0/G1期相比较，雷公藤甲素序贯吉非替尼组主要把细胞抑制在G2/M期。在肺腺癌H1975中，所有序贯模型组都主要通过活化Caspase-9/Caspase-3来诱导激活细胞凋亡通路。结论 先用雷公藤甲素再用吉非替尼治疗模式可能是克服T790M突变耐药的一个新选择。.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Cell Proliferation; Diterpenes; Epoxy Compounds; ErbB Receptors; Gefitinib; Humans; Lung Neoplasms; Phenanthrenes; Protein Kinase Inhibitors; Quinazolines

It has been demonstrated that triptolide inhibits the growth of several types of cancer cells in vitro and prevents tumor growth in vivo by inducing apoptosis and autophagy. Here we showed that Tripchlorolide (T4) significantly suppressed the proliferation of A549 cells in a dose- and time-dependent manner. This suppressive effect was diminished when cells were pretreated with 3-Methylamphetamine (3-MA). After the cells were treated with T4, the LC3 II protein expression was significantly increased, and autophagosomes were observed by TEM. However, almost no apoptosis was observed in A549 treated with T4. These results suggest that T4 induces A549 cell death predominantly through the activation of the autophagy pathway instead of the apoptosis pathway.

Topics: Adenocarcinoma; Adenocarcinoma of Lung; Apoptosis; Autophagy; Cell Death; Cell Line, Tumor; Cell Survival; Diterpenes; Humans; Lung Neoplasms; Phenanthrenes; Signal Transduction; Up-Regulation