Radiotherapy for small-cell lung cancer—Where are we heading?

KCNQ1OT1 lncRNA affects the proliferation, apoptosis, and chemoresistance of small cell lung cancer cells via the JAK2/STAT3 axis

Background

Small cell lung cancer (SCLC) is a devastating and aggressive neuroendocrine carcinoma characterized by high cellular proliferation and early metastatic spread. Numerous studies have demonstrated that long noncoding RNAs (lncRNAs) can regulate tumor generation and development, including in SCLC. The current study aimed to assess the effect of the lncRNA, KCNQ1OT1, on the proliferation, apoptosis, and chemoresistance of SCLC and the potential underlying molecular mechanism.

Methods

Matched chemo-resistant and sensitive cells were applied to RNA isolation and followed by expression profiling by microarray analysis and subsequent quantitative polymerase chain reaction (qPCR) validation. Cell viability and apoptosis were determined by Cell Counting Kit-8 and flow cytometry to examine the chemoresistance and apoptosis of KCNQ1OT1 knockdown with lentivirus-mediated RNA interference. Furthermore, cell proliferation was studied by colony formation, and invasion and migration were tested by Transwell cell invasion and wound-healing assays, respectively. A tumor xenograft model was established to determine the role of KCNQ1OT1 in tumor growth and chemoresistance in response to KCNQ1OT1 knockdown in vivo. Western blot analysis, qPCR, and immunohistochemistry were used to detect the levels of messenger RNA (mRNA) Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway-related markers.

Results

Higher expression of KCNQ1OT1 was detected in SCLC chemo-resistant verso chemo-sensitive cells. Knockdown of KCNQ1OT1 inhibited SCLC cell viability and cloning ability, hindered cell migration and invasion, induced apoptosis in vitro, and suppressed tumor growth and chemoresistance in vivo, by activating the JAK2/STAT3 signaling pathway.

Conclusions

This is the first study to indicate that lncRNA KCNQ1OT1 promotes cell proliferation and invasion, and prevents apoptosis of SCLC by activating the JAK2/STAT3 pathway.

Meta-analysis of prophylactic cranial irradiation or not in treatment of extensive-stage small-cell lung cancer: The dilemma remains

PURPOSE

The role of prophylactic cranial irradiation (PCI) in treatment of extensive-stage small-cell lung cancer (SCLC) is controversial. The aim of this study was to systematically evaluate the efficacy and safety of using PCI in the treatment of extensive-stage SCLC. In the present study, we examined whether PCI was essential for the optimal treatment of extensive-disease small-cell lung cancer.

MATERIAL AND METHODS

We searched the PubMed, Embase, Medline, and China National Knowledge Infrastructure databases to identify articles that assessed the efficacy of PCI in treating extensive-stage small-cell lung cancer patients.

RESULTS

We identified 8 studies that involved a total of 982 patients who received PCI (PCI group) and a total of 4509 patients who did not receive PCI (control group). The results showed that PCI significantly improved the 1-year overall survival rate (HR=1.50; 95% CI: 1.23-1.82; I²=67%; P<0.0001) and reduced the incidence of brain metastasis (HR=0.46; 95% CI: 0.37-0.58; I²=6%; P<0.00001).

CONCLUSION

PCI improves the 1-year overall survival rate and reduces the risk of brain metastasis in patients with extensive-stage SCLC.

Comparison Of Long Term Results Between Matched Chemoradiotherapy And Surgery For Limited Stage Small Cell Lung Cancer

Purpose

To compare the efficacy of chemoradiotherapy or surgery for limited-stage small cell lung cancer (SCLC).

Patients and methods

A retrospective analysis was performed on 138 patients with limited-stage SCLC who received surgery (69 patients) or chemoradiotherapy (69 patients) between January 2000 and September 2016 in Zhejiang Cancer Hospital. Patients of the chemoradiotherapy group were selected by using “pair-matched case-control” methodology from a cohort of 503 patients who received chemoradiotherapy.

Results

The major prognostic factors, including T, N stage, treatment duration, age, gender, and whether or not they received prophylactic cranial irradiation were well balanced between two groups. The median overall survival (OS) time and 5-year OS rate were 37.1 months and 45.0% in the surgical group vs 45.0 months and 45.0% in the chemoradiotherapy group (P=0.846). The median progression-free survival (PFS) time and 5-year PFS rate were 27.1 months and 37.8% vs 36.2 months and 40.0%, respectively, in the two groups (P=0.610). The 5-year OS rate (62.3% vs 40.1%, P=0.038) and 5-year PFS rate (80.1% vs 40.1%, P=0.048) in the surgical group were significantly higher than those of the chemoradiotherapy group in patients with stage I disease. The 5-year OS rate (41.2% vs 50.6%, P=0.946) and 5-year PFS rate (64.7% vs 42.1%, P=0.280) of surgery for stage II SCLC were comparable to chemoradiotherapy. As for stage III SCLC, compared with the surgical group, the chemoradiotherapy group had a better 5-year OS trend (25.1% vs 47.6%, P=0.220), but the difference did not reach statistical significance.

Conclusion

Surgery could confer survival benefits in patients with p-stage I disease, but not in patients with p-stage II and III disease.

Protective efficacy using Cape- golden berry against pre-carcinogenic aflatoxins induced in rats

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Vacuum drying saves the CGB bioactive components.

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Addition of CGB to rats’ diet presents good health effects.

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Aflatoxins caused vigorous impacts for rats’ biochemical parameters and tissues.

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CGB showed an ability for AF–precarcinogenicity reduction in liver tissues.

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CGB recorded enhancing the liver enzymes and blood parameters of AFs-rats.

Aflatoxins are harmful compounds that induced carcinogenic impacts on tissues. It could generate oxidative stress causing cells damage. Bioactive substances from natural plants could avoid mycotoxins’ bad impacts. Cape-goldenberry (CGB), a source of active substances, was vacuum-dried at 30 °C then milled. Fresh and dried CGB-powder properties were estimated. Animal experiment was designed using six rat-groups to evaluate CBG effect to reduce harmful effect of aflatoxins. Rats treated groups were orally administrated by aflatoxins (AFs) with or without CGB in diets. Blood parameters, liver and kidney functions, serum lipids, and liver histological changes were estimated. The CGB powder showed several time doubles of phenolics, flavonoids, and antioxidants than fresh fruits. Diet supplementation by CGB of AFs-treated rats showed enhancement in final weight, food efficiency, and weight gain compared to AFs treatment only. Also, liver and kidney functions, liver enzymes, iron level, tumors indicator, and serum lipids of AFs- rats. Moreover, total protein, albumin, and globulin reduction by AFs have been improved by CGB presence in diets. Histopathological studies for AFs-rats liver showed dilated blood sinusoids with aggregation of inflammatory, Kupffer cell hyperplasia, degenerated hepatocytes, and apoptotic cells. However, in AFs-rat groups fed CGB in diets, liver hepatocytes appeared to be almost normal similar to the control. Results pointed out that CGB recorded a corrective action for aflatoxin B₁ and G₁ toxicity. This was recorded for the blood and serum parameters, and liver enzymes. This CGB action avoiding AFs-toxicity was more clearly declared in the liver tissues.

The impact of prophylactic cranial irradiation for post-operative patients with limited stage small cell lung cancer

To evaluate the impact of prophylactic cranial irradiation (PCI) on the prognosis of patients who received definitive surgery for surgically resected small cell lung cancer (SCLC).A retrospective analysis was performed on post-operative SCLC patients treated in Zhejiang Cancer Hospital from January 2003 to December 2015. According to the treatment modality, patients were allocated to PCI group and non-PCI group. Univariate survival analysis was performed by the Kaplan-Meier method. Multivariate survival analysis was performed by a Cox proportional hazards model.A total of 52 patients were included for analysis, among which, 19 patients were in PCI group and 33 were in non-PCI group. Multivariate analysis revealed that PCI (HR = .330; P = .041) was an independently favorable prognostic factor for the overall survival. The median overall survival (OS) time was 32.9 months in PCI group, and 20.4 months in non-PCI group. The 2-year OS rates were 78.0% and 38.0% in PCI and non-PCI group respectively (P = .023). The brain metastasis-free survival (BMFS) rate at 2-year in PCI group was significantly higher than those of non-PCI group (89.0% vs 53.0%, respectively, P = .026).In conclusion, PCI might be suggested for limited SCLC patients who received definitive surgery.

Programmed death-ligand 1 positivity can predict improved survival and a lower risk of brain metastasis in patients with resectable small cell lung cancer

The present study aimed to investigate the expression of programmed death-ligand 1 (PD-L1) in resectable small cell lung cancer (SCLC) and investigate its predictive value for survival and brain metastasis (BM). Postoperative SCLC specimens were immunostained with the SP142 antibody against PD-L1. Positive PD-L1 expression was defined as PD-L1 expression in ≥5% of tumor cells. A total of 80 patients were recruited between January 2010 and December 2012. PD-L1 was expressed in 65.0% (52/80) of all patients and 59.3% (16/27) of patients with BM. The median survival time (MST) was longer in the PD-L1(+) group (46.4 vs. 28.5 months, P=0.002). There was no significant difference in the MST between patients with PD-L1(+) or (−) BM (P=0.55). The 3-year risk of BM in the PD-L1(+) group was lower than that in the PD-L1(−) group (24.1 vs. 48.4%, P=0.046). PD-L1 was an independent factor for overall survival (OS) [hazard ratio (HR)=0.485, P=0.011] and BM (HR=0.335, P=0.024). The present study concludes that PD-L1 is commonly expressed in SCLC and is associated with OS and BM.

Evaluation of factors associated with platinum-sensitivity status and survival in limited-stage small cell lung cancer patients treated with chemoradiotherapy

In this retrospective study, we analyzed the association of clinicopathological factors and therapeutic plans with platinum-sensitivity status and survival of limited-stage small cell lung cancer (LS-SCLC) patients. We enrolled 452 LS-SCLC patients with 279 platinum sensitive and 173 platinum refractory patients. The low serum neuro-specific enolase levels (NSE; p = 0.011), neutrophil-to-lymphocyte ratios (NLR; p = 0.013) and higher objective response rates (p = 0.003) were associated with sensitive group but not the refractory group. Multivariate analysis showed that treatment modality (HR = 0.267, p < 0.001), serum lactate dehydrogenase (LDH; HR = 1.894, p = 0.016), NLR (HR = 2.043, p = 0.043) and platinum-sensitivity status (HR = 0.561, p = 0.036) were independent prognostic factors for survival. We further showed that the numbers of chemotherapy cycles and response to first-line therapy were independent prognostic factors for refractory patients only. Our study demonstrates that platinum-sensitivity status is of prognostic importance, as it is strongly associated with survival in LS-SCLC patients.

Thoracic radiation therapy could give survival benefit to elderly patients with extensive-stage small-cell lung cancer

AIM

To evaluate the effect of thoracic radiation therapy (TRT) in elderly patients (aged ≥65 years) with extensive-stage small-cell lung cancer (ES-SCLC).

PATIENTS & METHODS

This study reviewed the records of 118 elderly patients with ES-SCLC (all with distant metastasis) through January 2006-December 2013. The patients were divided into either a chemotherapy (ChT)/TRT-combination group or a ChT-alone group.

RESULTS

The median survival time and 3-year overall survival rates in the ChT/TRT group were significantly higher than those in the ChT-alone group (17.0 vs 11.7 months; 18.1 vs 14.9%; p = 0.014). The 3-year overall survival rates in patients who received prophylactic cranial irradiation were also higher than the rates in patients who did not receive prophylactic cranial irradiation (18.1 vs 5.1%; p = 0.708).

CONCLUSION

TRT combined with ChT could provide a survival benefit to elderly patients with ES-SCLC.

[Effects of Local Radiation Combined with Chemotherapy in the treatment of Patients with Extensive-stage Small Cell Lung Cancer]

BACKGROUND AND OBJECTIVE

Chemotherapy is a highly efficient primary treatment for extensive-stage small cell lung cancer (ES-SCLC). However, patients receiving such treatment are prone to develop drug resistance. Local treatment is palliative and thus can alleviate the local symptoms and improve quality of life, but limited evidence is available for prolonging survival. Hence, this study evaluated the role of local treatment in chemotherapy of patients with ES-SCLC.

METHODS

A total of 302 ES-SCLC cases were enrolled in this retrospective study. Prognostic factors were analyzed by Kaplan-Meier and Cox multivariate proportional hazards model.

RESULTS

Median progression-free survival (PFS) and median survival time (MST) of the patients were 4.4 and 10.4 months, respectively. 1-, 2-, and 3-year survival rates were 37.8%, 10.2% and 4.4%, correspondingly. The MST of the primary tumor radiotherapy plus chemotherapy group was 14.3 months, whereas that of the chemotherapy group was 8.2 months (P<0.01). The MSTs of multiple-site, single-site, and non-metastasis local treatments were 18.7, 12.3 and 8.9 months, respectively (P<0.01). The MSTs of initiative, passive, and non-metastasis local treatments were 16.0, 10.9 and 9.4 months, correspondingly (P<0.01). The MSTs of patients with prophylactic cranial irradiation (PCI) and those without PCI were 19.8 and 9.9 months, respectively (P<0.01). Primary tumor radiotherapy, metastasis local treatment, and PCI were independent prognostic factors for ES-SCLC.

CONCLUSIONS

Primary tumor radiotherapy, metastasis local treatment, and PCI can significantly improve survival in patients with ES-SCLC.
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Increased serum carcinoembryonic antigen level can predict poor survival of patients with small cell lung cancer

Increased serum tumor biomarkers are usually associated with huge tumor burden, but the prognostic value of these markers remains controversial. The serum levels of carcinoembryonic antigen (CEA), nerve cell-specific enolase, and lactate dehydrogenase in 281 patients with small cell lung cancer (SCLC) were analyzed in this study. Increased serum CEA levels were observed in 92 (32.7%) patients. Survival was superior in patients with normal serum CEA levels compared with those with increased serum CEA levels. The median survival time, 2-year overall survival (OS) rate, and 3-year OS rate were 19.1 months vs 14.6 months, 42.7% vs 28.3%, and 30.6% vs 14.1%, respectively (P = 0.002). In multivariate analysis, extensive-stage (ES)-SCLC (hazard ratio [HR] = 1.936, P = 0.001), an increased serum CEA level (HR = 1.432, P = 0.021) at diagnosis, and <4 cycles of chemotherapy (ChT) (HR = 0.432, P = 0.001) were independent negative prognostic factors for the OS. Additionally, normal CEA level (HR = 1.678, P = 0.012), treatment modalities including surgery (HR = 1.595, P = 0.049), and ≥ 4 cycles of ChT (HR = 1.880, P = 0.004) were independent positive prognostic factors for OS in patients with local disease. In the subgroup with ES-SCLC, normal serum CEA level (HR = 1.608, P = 0.043), thoracic radiation therapy (HR = 1.744, P = 0.005), and ≥ 4 cycles of ChT (HR = 2.626, P = 0.001) were independent positive prognostic factors for OS.

Risk factors for brain metastases in completely resected small cell lung cancer: a retrospective study to identify patients most likely to benefit from prophylactic cranial irradiation

Background

The role of prophylactic cranial irradiation (PCI) on small cell lung cancer (SCLC) has been established based on the two-stage system of limited versus extensive disease and the treatment modality of chemoradiotherapy. However, the use of PCI after combined-modality treatment with surgery for resectable limited-stage SCLC has not been investigated sufficiently. We conducted a retrospective study to evaluate risk factors for brain metastasis (BM) in patients with surgically resected SCLC to identify those most likely to benefit from PCI.

Patients and methods

The records of 126 patients with completely resected SCLC and definitive TNM stage based on histological examination between 2003 and 2009 were reviewed. The cumulative incidence of BM was estimated using the Kaplan–Meier method and differences between the groups were analyzed using the log-rank test. Multivariate Cox regression analysis was applied to assess the risk factors of BM.

Results

Twenty-eight patients (22.2%) developed BM at some point during their clinical course. The actuarial risk of developing BM at 3 years was 9.7% in patients with p-stage I disease, 18.5% in patients with p-stage II disease, and 35.4% in patients with p-stage III disease (p = 0.013). The actuarial risk of developing BM at 3 years in patients with LVI was 39.9% compared to 17.5% in patients without LVI (p = 0.003). Multivariate analysis identified pathologic stage (hazard ratio [HR] = 2.013, p = 0.017) and LVI (HR = 1.924, p = 0.039) as independent factors related to increased risk of developing BM.

Conclusion

Patients with completely resected p-stage II-III SCLC and LVI are at the highest risk for BM.

Is pre-trial quality assurance necessary? Experiences of the CONVERT Phase III randomized trial for good performance status patients with limited-stage small-cell lung cancer

OBJECTIVE

This study is an analysis of the pre-trial quality assurance (QA) exercises submitted by clinicians from radiotherapy (RT) centres across Europe and Canada to qualify for participation in the CONVERT trial.

METHODS

QA exercises submitted by 64 clinicians at 64 RT centres were included in this analysis. The exercises included the completion of a trial-specific questionnaire and submission of a treatment plan, for both trial arms, for a patient fitting the eligibility criteria of the trial. This article describes the QA programme set up for the CONVERT trial and identifies deviations from the trial protocol. Patient eligibility, disease and critical structure outlining and treatment planning technique were assessed.

RESULTS

Results from QA trial-specific questionnaires received between February 2008 and September 2011, returned as part of the QA exercise, indicated that the majority of centres (70.3%) were using 6-MV photons and type B treatment planning system algorithms (57.8%). 90.6% of clinicians assessed submitted data for patients who fitted the eligibility criteria for the trial. There were inconsistencies in outlining of gross tumour volume (GTV) and organs at risk, mainly heart and oesophagus, and in the use of margins around the GTV.

CONCLUSION

Such a QA programme helps to ensure that centres conform to trial protocol and should reduce inconsistencies in RT planning that may confound the results of the CONVERT trial.

ADVANCES IN KNOWLEDGE

Few studies reporting pre-trial QA have been published to date. This article outlines the importance of such a QA programme in the context of multicentre Phase III studies.

Management of small cell lung cancer: recent developments for optimal care

Small cell lung cancer (SCLC) represents approximately 13% of all lung cancer diagnoses and the incidence has reduced over the last 20 years. Treatment of SCLC remains challenging because of its rapid growth, early dissemination and development of drug resistance during the course of the disease. Chemotherapy remains the cornerstone of treatment for limited (LD) and extensive disease (ED), with concurrent chemotherapy and radical thoracic radiotherapy representing the best treatment option for fit patients with LD. Platinum-based chemotherapy is the treatment of choice in fit patients with good organ function, and the radiosensitizing effect of cisplatin is critically important for concurrent chemoradiotherapy in LD. Anthracycline-containing regimens represent a viable alternative for patients where platinum-based chemotherapy is contraindicated. Patients who relapse or progress after first-line chemotherapy have a very poor prognosis. Second-line therapy may produce a modest clinical benefit. Maintenance chemotherapy has not been shown to convincingly improve outcomes for SCLC. A number of targeted agents have been investigated in LD and ED, mostly in unselected populations, with disappointing results. Prophylactic cranial irradiation has been shown to reduce the incidence of brain metastases and prolong survival for both LD and ED without negative impact on quality of life (QOL) and cognitive function. Ongoing trials will shed some light on the impact of thoracic radiotherapy on QOL, symptom control and survival in ED SCLC patients who benefitted from first-line chemotherapy.

Experience with carboplatin and etoposide maintenance chemotherapy in patients with extensive stage small cell lung cancer

PURPOSE

To determine whether maintenance therapy with carboplatin and etoposide improves progression-free and overall survival in patients with extensive stage small cell lung cancer, compared to the standard four to six cycles of cisplatin and etoposide.

METHODS

Forty-two patient records (25 males and 17 females) were retrospectively reviewed in a single community practice. All patients were over the age of 18, with pathologically and radiographically proven extensive stage small cell lung carcinoma (SCLC). The starting doses of chemotherapy were carboplatin, AUC (area under the curve) of 6 IV day 1, and etoposide, 100 mg/m² IV days 1-3. The regimen was administered every 3 weeks and increased to every 4 to 5 weeks as tolerated or until documented progression occurred. Varying second-line chemotherapies were used.

RESULTS

Median overall survival was 17 months from diagnosis, with a progression-free survival of 15 months. Seventy-nine percent of the patients survived more than 10 months. The 1- and 2-year overall survival (OAS) rates were 0.74 (31 patients) and 0.31 (13 patients), respectively. The 1- and 2-year progression free survival (PFS) rates were 0.50 (21 patients) and 0.21 (9 patients), respectively.

CONCLUSION

The improved overall and progression-free survival compared to the current standard in this small single center cohort suggests that maintenance therapy with carboplatin and etoposide to progression may be a prudent area for further investigation in a properly powered randomized, controlled trial.

Thoracic radiation therapy improves the overall survival of patients with extensive-stage small cell lung cancer with distant metastasis

BACKGROUND

The authors conducted a retrospective study to evaluate the effects of thoracic radiation therapy (TRT) for patients with extensive-stage small cell lung cancer (ED-SCLC).

METHODS

Between January 2003 and December 2006, the records of 119 patients who were diagnosed with ED-SCLC (all with distant metastasis [M1]) were included in the study. Sixty patients received chemotherapy (ChT) and TRT (ChT/TRT), and 59 patients received ChT alone. The ChT regimens consisted of either carboplatin and etoposide (CE) or cisplatin and etoposide (PE). The total dose of TRT ranged from 40 to 60 grays (Gy) at 1.8 to 2.0 Gy per fraction.

RESULTS

For the entire group, the median survival was 13 months, and the 2-year and 5-year overall survival (OS) rates were 26.1% and 6.5%, respectively. The median survival and the 2-year and 5-year OS rates were 17 months, 35%, and 7.1%, respectively, in the ChT/TRT group and 9.3 months, 17%, and 5.1%, respectively, in the ChT group (P = .014). However, this improvement was achieved at the expense of low toxicity. Multivariate analysis revealed that receiving ≥4 cycles of ChT (P = .032) and TRT (P = .005) were favorable prognostic factors for OS. Of all toxicities, only high-grade leucopenia (grade >3) was more frequent in the ChT/TRT group.

CONCLUSIONS

The addition of TRT to ChT improved the OS of patients with ED-SCLC. Furthermore, receiving ≥4 cycles of ChT and TRT were independent, favorable prognostic factors for OS.

Use of G-CSF during concurrent chemotherapy and thoracic radiotherapy in patients with limited-stage small-cell lung cancer safety data from a phase II trial

There is paucity of data in the literature regarding the safety of combining granulocyte colony stimulating factor (G-CSF) during chemo-radiotherapy (CTRT) in lung cancer patients. The ASCO 2006 recommendations advise against use of CSFs during concomitant mediastinal CTRT. The only randomised study evaluating CSFs in this context showed significant increase in grade 3/4 thrombocytopenia and an excess of pulmonary toxic deaths. In the context of a phase II trial, 38 patients with limited-stage small cell lung cancer were randomised to receive once-daily (66 Gy in 33 fractions) or twice-daily (45 Gy in 30 fractions) radiotherapy. Radiotherapy (RT) was given concurrently with cisplatin and etoposide. G-CSF was given as primary or secondary prophylaxis or as a therapeutic measure during an episode of febrile neutropenia according to local protocols. Common terminology criteria for adverse events (CTCAE) v3.0 was used to record toxicity. Thirteen (34%) of 38 patients received G-CSF concurrently with RT. With a median follow-up of 16.9 months, there were no treatment related deaths reported. Seven (54%) patients experienced grade 3/4 thrombocytopenia and 5 (38%) experienced grade 3/4 anaemia. Thirty-one percent required platelet transfusions. No episodes of bleeding were observed. There were no cases of grade 3/4 acute pneumonitis. These data suggests that with modern three-dimensional (3D) conformal RT, G-CSF administration concurrently with CTRT does not result in the increase risk of pulmonary toxicity, but does increase the risk of thrombocytopenia. Whether the risks of thrombocytopenia are outweighed by the outcome of timely early concurrent CTRT is being evaluated prospectively in the ongoing phase III CONVERT trial (NCT00433563) in which G-CSF is permitted during thoracic irradiation.

Radiogenomics predicting tumor responses to radiotherapy in lung cancer

The recently developed ability to interrogate genome-wide data arrays has provided invaluable insights into the molecular pathogenesis of lung cancer. These data have also provided information for developing targeted therapy in lung cancer patients based on the identification of cancer-specific vulnerabilities and set the stage for molecular biomarkers that provide information on clinical outcome and response to treatment. In addition, there are now large panels of lung cancer cell lines, both non-small-cell lung cancer and small-cell lung cancer, that have distinct chemotherapy and radiation response phenotypes. We anticipate that the integration of molecular data with therapy response data will allow for the generation of biomarker signatures that predict response to therapy. These signatures will need to be validated in clinical studies, at first retrospective analyses and then prospective clinical trials, to show that the use of these biomarkers can aid in predicting patient outcomes (eg, in the case of radiation therapy for local control and survival). This review highlights recent advances in molecular profiling of tumor responses to radiotherapy and identifies challenges and opportunities in developing molecular biomarker signatures for predicting radiation response for individual patients with lung cancer.

4beta-Hydroxywithanolide E from Physalis peruviana (golden berry) inhibits growth of human lung cancer cells through DNA damage, apoptosis and G2/M arrest

Background

The crude extract of the fruit bearing plant, Physalis peruviana (golden berry), demonstrated anti-hepatoma and anti-inflammatory activities. However, the cellular mechanism involved in this process is still unknown.

Methods

Herein, we isolated the main pure compound, 4β-Hydroxywithanolide (4βHWE) derived from golden berries, and investigated its antiproliferative effect on a human lung cancer cell line (H1299) using survival, cell cycle, and apoptosis analyses. An alkaline comet-nuclear extract (NE) assay was used to evaluate the DNA damage due to the drug.

Results

It was shown that DNA damage was significantly induced by 1, 5, and 10 μg/mL 4βHWE for 2 h in a dose-dependent manner (p < 0.005). A trypan blue exclusion assay showed that the proliferation of cells was inhibited by 4βHWE in both dose- and time-dependent manners (p < 0.05 and 0.001 for 24 and 48 h, respectively). The half maximal inhibitory concentrations (IC₅₀) of 4βHWE in H1299 cells for 24 and 48 h were 0.6 and 0.71 μg/mL, respectively, suggesting it could be a potential therapeutic agent against lung cancer. In a flow cytometric analysis, 4βHWE produced cell cycle perturbation in the form of sub-G₁ accumulation and slight arrest at the G₂/M phase with 1 μg/mL for 12 and 24 h, respectively. Using flow cytometric and annexin V/propidium iodide immunofluorescence double-staining techniques, these phenomena were proven to be apoptosis and complete G₂/M arrest for H1299 cells treated with 5 μg/mL for 24 h.

Conclusions

In this study, we demonstrated that golden berry-derived 4βHWE is a potential DNA-damaging and chemotherapeutic agent against lung cancer.

Fern plant-derived protoapigenone leads to DNA damage, apoptosis, and G(2)/m arrest in lung cancer cell line H1299

Protoapigenone, isolated from the native fern plant Thelypteris torresiana, has anticancer activity against some cancer cells. However, the toxicological mechanism for protoapigenone is still unknown. Here, we investigated the anticancer effect of protoapigenone on human lung cancer cell lines. The comet assay showed that DNA damage induced by protoapigenone is dose-dependent. Trypan blue exclusion showed that the cell killing by protoapigenone is both time and dose dependent. The IC(50) of protoapigenone for 12, 24, and 48 h in H1299 cells is 6.11, 2.74, and 1.49 microM, respectively. Flow cytometry showed cell cycle perturbation such as sub-G(1) accumulation (at 1.57 microM for 48 h and at 3.57 microM for 12 and 24 h) and G(2)/M arrest (at 3.57 microM for 12 and 24 h) for protoapigenone. The sub-G(1) accumulation phenomena in the 3.57 microM for 24 h sample were shown to be apoptosis using Annexin V-immunofluorescence/propidium iodide staining. These results suggest protoapigenone is a potential chemotherapeutic agent for lung cancers.