Second-line therapy for small-cell lung cancer

Role of microRNAs in regulation of doxorubicin and paclitaxel responses in lung tumor cells

Lung cancer as the leading cause of cancer related mortality is always one of the main global health challenges. Despite the recent progresses in therapeutic methods, the mortality rate is still significantly high among lung cancer patients. A wide range of therapeutic methods including chemotherapy, radiotherapy, and surgery are used to treat lung cancer. Doxorubicin (DOX) and Paclitaxel (TXL) are widely used as the first-line chemotherapeutic drugs in lung cancer. However, there is a significant high percentage of DOX/TXL resistance in lung cancer patients, which leads to tumor recurrence and metastasis. Considering, the side effects of these drugs in normal tissues, it is required to clarify the molecular mechanisms of DOX/TXL resistance to introduce the efficient prognostic and therapeutic markers in lung cancer. MicroRNAs (miRNAs) have key roles in regulation of different pathophysiological processes including cell division, apoptosis, migration, and drug resistance. MiRNA deregulations are widely associated with chemo resistance in various cancers. Therefore, considering the importance of miRNAs in chemotherapy response, in the present review, we discussed the role of miRNAs in regulation of DOX/TXL response in lung cancer patients. It has been reported that miRNAs mainly induced DOX/TXL sensitivity in lung tumor cells by the regulation of signaling pathways, autophagy, transcription factors, and apoptosis. This review can be an effective step in introducing miRNAs as the non-invasive prognostic markers to predict DOX/TXL response in lung cancer patients.

A phase II study of antiangiogenic therapy (Apatinib) plus chemotherapy as second-line treatment in advanced small cell lung cancer

INTRODUCTION

Currently, only a few options are available for the treatment of patients with small-cell lung cancer (SCLC) after the failure of first-line platinum-based chemotherapy. The present study aimed to evaluate the efficacy and safety of apatinib plus chemotherapy for second-line treatment of advanced SCLC.

PATIENTS AND METHODS

This prospective clinical trial recruited patients treated with apatinib plus second-line chemotherapy until disease progression or intolerable toxicity. Logrank test power analysis was used for calculating samples. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were objective response rate (ORR), disease control rate (DCR), overall survival (OS), and safety.

RESULTS

A total of 29/31 enrolled patients were available for response evaluation until October 2019. The ORR and DCR were 27.59% (8/29) and 96.55% (28/29), respectively. The median PFS and OS were 7.36 months and 14.16 months, respectively, indicating better efficacy compared with the standard second-line chemotherapies. The most common adverse events (AEs) were neutropenia (41.94%, 13/31), followed by leucopenia (35.48%, 11/31) and thrombocytopenia (25.81%, 8/31). The grade 3-4 AEs occurred in 12 (38.71%) patients, of which neutropenia (19.35%, 6/31), leucopenia (9.68%, 3/31), and proteinuria (6.45%, 2/31) were most common. Patients receiving an initial dose of apatinib 250 mg had a better tolerance.

CONCLUSION

Antiangiogenic therapy plus chemotherapy had encouraging efficacy in advanced SCLC patients, which provides an insight into the current status of second-line therapy in SCLC.

Banxia Xiexin Decoction Is Effective to Prevent and Control Irinotecan-Induced Delayed Diarrhea in Recurrent Small Cell Lung Cancer

Background: Irinotecan (CPT-11) can be used as a first-line therapeutic drug against extensive-stage small cell lung cancer (SCLC); it can also be used in second-line treatment for SCLC. CPT-11-induced delayed diarrhea restricts its clinical application. This study aimed to confirm whether Banxia Xiexin decoction was effective in preventing and controlling CPT-11-induced delayed diarrhea. Methods: A total of 27 patients with recurrent SCLC undergoing chemotherapy regimens including CPT-11 were enrolled for the study. UGT1A1*28, UGTlAl*6, ABCB1*2, and SLCO1B1*15 gene polymorphisms were detected. If delayed diarrhea occurred in the first cycle of chemotherapy, Banxia Xiexin decoction was orally administered for 5 consecutive days starting 1 day before the second cycle of chemotherapy to prevent and control the delayed diarrhea. The objective response, overall survival, and toxicity were recorded. Results: Complete response, partial response, and stable disease were observed in none, 6, and 10 patients, respectively. Delayed diarrhea occurred in 6 patients, and 4 of 5 patients were relieved or controlled using Banxia Xiexin decoction. The median overall survival was 6 months. Conclusion: Banxia Xiexin decoction appeared to prevent and control delayed diarrhea induced by CPT-11 in this small observational study, and further study with a larger sample size, including potentially randomized trials, is suggested.

MCAM Mediates Chemoresistance in Small-Cell Lung Cancer via the PI3K/AKT/SOX2 Signaling Pathway

Despite favorable responses to initial therapy, small-cell lung cancer (SCLC) relapse occurs within a year and exhibits resistance to multiple drugs. Because of limited accessibility of patient tissues for research purposes, SCLC patient-derived xenografts (PDX) have provided the best opportunity to address this limitation. Here, we sought to identify novel mechanisms involved in SCLC chemoresistance. Through in-depth proteomic profiling, we identified MCAM as a markedly upregulated surface receptor in chemoresistant SCLC cell lines and in chemoresistant PDX compared with matched treatment-naïve tumors. MCAM depletion in chemoresistant cells reduced cell proliferation and reduced the IC₅₀ inhibitory concentration of chemotherapeutic drugs in vitro This MCAM-mediated sensitization to chemotherapy occurred via SOX2-dependent upregulation of mitochondrial 37S ribosomal protein 1/ATP-binding cassette subfamily C member 1 (MRP1/ABCC1) and the PI3/AKT pathway. Metabolomic profiling revealed that MCAM modulated lactate production in chemoresistant cells that exhibit a distinct metabolic phenotype characterized by low oxidative phosphorylation. Our results suggest that MCAM may serve as a novel therapeutic target to overcome chemoresistance in SCLC. Cancer Res; 77(16); 4414-25. ©2017 AACR.

Second-line therapy for small cell lung cancer: exploring the potential role of circulating tumor cells

BACKGROUND

Small cell lung cancer (SCLC) is an aggressive and invasive variant of lung tumors. SCLC, especially in advanced stages, is distinguished by extremely high numbers of circulating tumor cells (CTCs) in comparison to other malignancies. CTCs are operative in tumor spread and are currently enumerated to assess prognosis and response to cytotoxic therapy. Chemosensitivity of SCLC CTCs compared to primary tumors and metastases is not known.

METHODS

Establishment of two SCLC CTC cell lines, namely BHGc7 and BHGc10, allowed the in vitro characterization of their chemosensitivity to the second-line chemotherapeutics topotecan and epirubicin in comparison to a range of SCLC cell lines.

RESULTS

The SCLC CTC cell lines exhibited an approximately 7- and 12-fold increased chemosensitivity to epirubicin compared to topotecan, respectively, in in vitro cytotoxicity assays. In comparison to a panel of six SCLC cell lines, the two CTC lines showed a significantly higher chemosensitivity to epirubicin (range, 3- to 16-fold) and topotecan (range, 2.2- to 14.4-fold), respectively.

CONCLUSIONS

CTC cell lines derived from SCLC patients with recurrent disease exhibit high chemosensitivity to epirubicin vs. topotecan and show considerable more cytotoxicity in response to both compounds in comparison to a panel of SCLC cell lines. Thus, a decrease in the number of CTCs in response to second-line chemotherapy in SCLC patients may overestimate the effect on resident SCLC lesions and metastases.

HSP-90 inhibitor ganetespib is synergistic with doxorubicin in small cell lung cancer

Small cell lung cancer (SCLC) at advanced stage is considered an incurable disease. Despite good response to initial chemotherapy, the responses in SCLC patients with metastatic disease are of short duration and resistance inevitably occurs. Although several target-specific drugs have altered the paradigm of treatment for many other cancers, we have yet to witness a revolution of the same magnitude in SCLC treatment. Anthracyclines, such as doxorubicin, have definite activity in this disease, and ganetespib has shown promising activity in preclinical models but underwhelming activity as a single agent in SCLC patients. Using SCLC cell lines, we demonstrated that ganetespib (IC50: 31 nM) was much more potent than 17-allylamino-17-demethoxygeldanamycin (17-AAG), a geldanamycin derivative (IC50: 16 μM). Ganetespib inhibited SCLC cell growth via induction of persistent G2/M arrest and Caspase 3-dependent cell death. MTS assay revealed that ganetespib synergized with both doxorubicin and etoposide, two topoisomerase II inhibitors commonly used in SCLC chemotherapy. Expression of receptor-interacting serine/threonine-protein kinase 1 (RIP1), a protein that may function as a pro-survival scaffold protein or a pro-death kinase in TNFR1-activated cells, was induced by doxorubicin and downregulated by ganetespib. Depletion of RIP1 by either RIP1 small interfering RNA (siRNA) or ganetespib sensitized doxorubicin-induced cell death, suggesting that RIP1 may promote survival in doxorubicin-treated cells and that ganetespib may synergize with doxorubicin in part through the downregulation of RIP1. In comparison to ganetespib or doxorubicin alone, the ganetespib+doxorubicin combination caused significantly more growth regression and death of human SCLC xenografts in immunocompromised mice. We conclude that ganetespib and doxorubicin combination exhibits significant synergy and is efficacious in inhibiting SCLC growth in vitro and in mouse xenograft models. Our preclinical study suggests that ganetespib and doxorubicin combination therapy may be an effective strategy for SCLC treatment, which warrants clinical testing.

Synergism of cyclin-dependent kinase inhibitors with camptothecin derivatives in small cell lung cancer cell lines

Advanced small cell lung cancer (SCLC) has a dismal prognosis. Modulation of the camptothecin topotecan, approved for second-line therapy, may improve response. Our recent finding of synergistic enhancement of the cytotoxic activity of camptothecin (CPT) by cyclin-dependent kinase 4 inhibitors is extended here to a panel of camptothecin analogs comprising 10-hydroxy-CPT (HOCPT), topotecan (TPT; 9-[(dimethylamino)-methyl]-10-hydroxy-CPT), 9-amino-CPT (9AC), 9-nitrocamptothecin (rubitecan), SN38 (7-ethyl-10-hydroxycamptothecin) and 10-hydroxy-9-nitrocamptothecin (CPT109) in combination with PD0332991, CDK4I, roscovitine and olomoucine. SCLC cell lines employed are chemoresistant NCI-H417 and DMS153 and the chemosensitive SCLC26A line established at our institution. The CPT analogs exhibiting highest cytotoxicity towards the three SCLC lines tested were SN38 and 9AC, followed by rubitecan, HOCPT, TPT and CPT109. NCI-H417 and DMS153 revealed an approximately 25-fold and 7-fold higher resistance compared to the chemosensitive SCLC26A cell line. Whereas the CDK4/6 inhibitor PD0332991 proved less effective to chemosensitize SCLC cells to CPT analogs, the CDK inhibitors CDK4I, roscovitine and olomoucine gave comparable chemosensitization effects in combination with 9AC, SN38, rubitecan and to a lesser extent with TPT and CPT109, not directly related with topoisomerase mRNA expression. In conclusion, small chemical modifications of the parent CPT structure result in differing cytotoxicities and chemomodulatory effects in combination with CDKIs of the resulting analogs.

Timing of Failure in Limited Disease (Stage I-III) Small-Cell Lung Cancer Patients Treated with Chemoradiotherapy: A Retrospective Analysis

Aims and background

Follow-up in limited disease (stage I-III) small cell lung cancer could be further optimized by assessment of the temporal and locational distribution of treatment failure after completion of chemoradiotherapy.

Methods and study design

Follow-up was retrospectively analyzed in 125 limited disease (stage I-III) small cell lung cancer patients with initial performance status WHO <3 who had successfully completed chemoradiotherapy. Thoracic irradiation was applied in the concurrent or sequential mode. Time from initial pathological diagnosis and treatment end to local, distant and brain recurrence was documented.

Results

One- and two-year progression-free survival rates were 50% and 27.2% in patients treated with concurrent and 45.2% and 14.2% in those treated with sequential chemoradiotherapy, respectively. Local relapse was documented in 14% patients treated with concurrent and 16% with sequential chemoradiotherapy. The distant failure rate was 43% in both subgroups. Up to the end of the follow-up period, more patients treated with concurrent chemoradiotherapy had developed brain metastases than those treated sequentially (37% vs 20%, P = 0.049). Median time (in days) to local relapse was 376 and 401 from the initial diagnosis, 200 and 309 from the end of chemotherapy, and 316 and 196 from the end of thoracic irradiation; to distant failure was 275 and 298 from the initial diagnosis, 151 and 157 from the end of chemotherapy and 180 and 84 from the end of thoracic irradiation; to brain relapse was 330 and 273 from the initial diagnosis, 123 and 151 from the end of chemotherapy and 213 and 73 from the end of thoracic irradiation in patients treated with concurrent and sequential chemoradiotherapy, respectively. There was no significant difference in the temporal distribution of treatment failure in either subgroup.

Conclusions

In more than half of the patients who developed a distant recurrence, including brain metastases, treatment failure occurred in the first year after the initial diagnosis. Intensified follow-up can be recommended at least in the first year, because no sufficient eradication of the systemic small cell lung cancer with the applied chemoradiotherapy protocol could be achieved.

Cisplatin for small cell lung cancer: Associated publications in Science Citation Index Expanded

This study was conducted to explore a bibliometric approach to quantitatively assess current research trends in cisplatin-containing chemotherapy for small cell lung cancer (SCLC), using related literature in the Science Citation Index Expanded database from 1992 to 2011. Articles were analyzed by the scientific output and research performances of countries and institutions. The distribution of key words in the article title and author-selected keywords were used to evaluate research trends. It was observed that the number of articles devoted to cisplatin-containing chemotherapy for SCLC did not increase with time. The USA and Japan were the top two countries with the highest number of articles devoted to cisplatin-containing chemotherapy for SCLC. In both countries, the number of articles did not increase with time, and a decreasing trend was identified in the USA over the last 10 years. This study demonstrates trends in cisplatin-containing chemotherapy for SCLC. The clinical application of novel drugs is required for successful SCLC treatment.

[Irinotecan plus temozolomide in refractory or relapsed pediatric solid tumors]

INTRODUCTION

The prognosis of refractory or relapsed pediatric solid tumors is very poor, and there is no standard treatment for this condition. The combination of irinotecan and temozolomide has proved useful in adults as a second-line treatment of different solid tumors. In pediatric patients, this combination has been effective in Ewing's sarcoma, neuroblastoma, and relapsed or refractory rhabdomyosarcoma.

PATIENTS AND METHODS

A retrospective study was conducted on 32 pediatric patients with refractory or relapsed solid tumors, who were treated with irinotecan and temozolomide in the Oncology Department at Children's Hospital Niño Jesus from September 2005 to June 2012. The clinical characteristics, treatment performed, toxicity and outcome, were analyzed.

RESULTS

Thirty-two patients received a total of 180 cycles. Of the 30 evaluable patients, 10 (33%) had a positive response (2 complete remission and 8 partial remission), and in 8 (27%) the disease remained stable. Almost all (94%) of the patients achieved a response in the first four cycles. Of the 180 cycles analyzed, only 50 (28%) had toxicity, and of these only 15 (8%) were grade iii-iv. The most common toxicity was diarrhea appearing in 18 patients. All patients received ambulatory treatment, except three of them who required hospitalization due to symptoms of their underlying disease.

CONCLUSION

The combination of irinotecan and temozolomide is well tolerated and active against pediatric refractory or relapsed solid tumors.

miRNA-214 modulates radiotherapy response of non-small cell lung cancer cells through regulation of p38MAPK, apoptosis and senescence

Background:

Radio- and chemotherapy (RT/CT) resistance hampers success in combating small and non-small cell lung cancers (SCLC/NSCLC). The underlying molecular mechanisms of RT/CT resistance of LCs are multifactorial and have been understood in part hitherto. miRNAs, key regulators of mRNAs, are well-recognised oncomirs; however, their role in regulating RT response remains poorly understood.

Methods:

Six human NSCLC and five SCLC cell lines with different SF2 values were investigated. Using microarray we examined whether expression of miRNAs is linked to the RT resistance of NSCLCs or SCLCs. Obtained data were validated by quantitative real-time PCR. Apoptosis and senescence were analysed using siRNA transfection, western blot and flow cytometry.

Results:

miRNA-21, miRNA-1827, miRNA-214, miRNA-339-5p, miRNA-625, miRNA-768-3p, miRNA-523-3p, miRNA-1227, miRNA-324-5p, miRNA-423-3p, miRNA-1301 and miRNA-1249 are differentially expressed in LC cells. miRNA-214 is upregulated in RT-resistant NSCLC cells relative to radiosensitive counterparts. Considering miRNA-214 as a putative regulator of RT resistance, we demonstrate that knockdown of miRNA-214 in radioresistant NSCLCs sensitised them to RT by stimulation of senescence. Consistently, overexpression of miRNA-214 in radiosensitive NSCLCs protected against RT-induced apoptosis. Protection was mediated by p38MAPK, as downregulation of this kinase could reverse the miRNA-214 overexpression-induced resistance of NSCLC cells.

Conclusion:

miRNA profiling of LC revealed putative RT resistance signalling circuits, which might help in sensitisation of LC to RT.

Radiation/paclitaxel treatment of p53-abnormal non-small cell lung cancer xenograft tumor and associated mechanism

BACKGROUND

Mutations in key tumor suppressor genes such as tumor protein 53 (TP53) and phosphatase and tensin homolog deleted on chromosome ten (PTEN) are the main genetic alterations in cancers. TP53 mutations have been found in most patients with non-small cell lung cancer (NSCLC), whereas PTEN mutations are rarely found in lung cancer, though most NSCLCs lack PTEN protein synthesis. However, the signaling involved in radio- and chemotherapy of NSCLC with wild-type PTEN and nonfunctional p53 is not clearly understood.

METHODS

In this study, we established a xenograft tumor model with H358 NSCLC cells expressing wild-type PTEN, but nonfunctional p53. Protein expression and phosphorylation of PTEN and its downstream signal molecules in NSCLC tissues were detected by Western blot.

RESULTS

We demonstrated that radiation and paclitaxel alone inhibited tumor growth, but a combined therapy of radiation and paclitaxel was more effective in inhibiting NSCLC tumor growth. Interestingly, both radiation and paclitaxel significantly increased PTEN protein expression and phosphorylation. Further identification of the affected PTEN downstream molecules showed that Akt phosphorylation at Ser(473) and Thr(308) residues was significantly decreased, whereas Bax and cleaved caspase-3 levels were significantly increased in tumor tissues treated with both radiation and paclitaxel. The combined treatment was more effective than either treatment alone in regulating the studied molecules. We also found that paclitaxel, but not radiation, inhibited phosphoinositide 3-kinase (PI3K) activity.

CONCLUSIONS

Our study suggested that a PTEN-PI3K-Akt-Bax signaling cascade is involved in the therapeutic effect of combined radiation/paclitaxel treatment in NSCLC without p53 expression. Our study also suggested that PTEN is an ideal target in tumors with wild-type PTEN and a lack of functional p53.