不同非小细胞肺癌细胞株中DNA-PKcs的表达及其与放射敏感性的关系

背景与目的：DNA依赖蛋白激酶催化亚基（DNA—dependent protein kinase catalytic subunit,DNA—PKcs）在电离辐射引起的DNA双链断裂的修复过程中起着关键作用,可影响组织细胞对放射治疗的敏感性。本研究通过检测DNA—PKcs在不同组织学类型非小细胞肺癌（non-small cell lung cancer,NSCLC）细胞中的表达情况,探讨其与放射敏感性的关系。方法：Western blot及DNA—PK活性分析法检测NSCLC细胞株A549、H1299、L78、PGCL3和H460中DNA—PKcs的含量与活性。成克隆实验分别测定各细胞株照射后的剂量一存活曲线,并分析放射敏感性与DNA—PKcs的关系。结果：成克隆实验结果显示：不同NSCLC细胞株的放射敏感性不同,A549细胞2Gy剂量照射下的存活分数（survival fraction at 2Gy,SF2）为0．74,H1299细胞为0．25,H460细胞为0．21,PGCL3细胞为0．48．L78细胞为0．58。Western blot显示各NSCLC细胞株中DNA-PKcs的表达有差异．A549细胞的DNA—PKcs表达水平为3．26±0．98,L78细胞为0．51±0．07,H1299细胞为0．51±0．11,H460细胞为0．86±0．23,PGCL3细胞为2．60±0．76。A549细胞的DNA—PKcs活性为8．30±1．03,H1299细胞为2．45±0．52,H460细胞为0．11±0．02。PGCL3细胞为4．13±0．87．L78细胞为0．42±0．07。在腺癌及大细胞癌中SF2与DNA—PKcs含量（P〈0．05,r=0．95）及活性（P=0．03,r=0．98）呈线性相关。结论：在腺癌及大细胞癌中．DNA-PKcs是判断细胞放射敏感性的重要因素。     

Postoperative irradiation in non-small cell lung cancer

A growing body of evidence suggests that postoperative irradiation for non-small cell lung cancer may cause life-threatening toxicity and, when the risk of local-regional recurrence is low, the toxicity of irradiation may outweight the benefit. However, many of these studies used outdated, even crude techniques. Although these techniques may be responsible for a significant amount of the toxicity reported in these studies, essentially no randomized or high-quality retrospective study has shown a survival benefit for postoperative irradiation for patients with N0 or N1 disease. The situation for N2 tumors is more positive. Taken as a whole, the available data suggest that, as a worst-case scenario, the net effect of adjuvant irradiation is neutral (with neither a net survival decrement nor a net advantage). As a best-case scenario, postoperative irradiation may improve the chance for long-term survival in patients with N2 tumors.     

Clinical challenges in targeting anaplastic lymphoma kinase in advanced non-small cell lung cancer

The revolution in individualized therapy for patients with advanced non-small cell lung cancer (NSCLC) has seen the emergence of a number of molecularly targeted therapies for distinct patient molecular subgroups. Activating anaplastic lymphoma kinase (ALK)-gene rearrangement has been detected in 3–7 % of NSCLC cases, and the ALK inhibitor crizotinib is now an approved treatment for patients with tumors harboring this event. However, resistance to ALK-targeted therapies is a ubiquitous problem in the management of advanced ALK-positive NSCLC and can be mediated by secondary kinase mutations or the activation of compensatory alternative oncogenic drivers. New, more potent ALK inhibitors such as ceritinib (LDK378), alectinib (CH5424802), and AP26113 are now emerging, together with an increased knowledge of the molecular basis of resistance. There is a need to evaluate the optimal clinical application of these new agents, either as sequential therapies or in combination with other targeted agents, to combat resistance and prolong survival in patients with ALK-positive NSCLC. The remarkable clinical activity of ALK inhibitors also emphasizes the importance of optimal diagnostic testing algorithms, to ensure that all eligible patients receive these breakthrough therapies.     

Hypofractionated irradiation for non-small cell lung cancer

Large radiation fractions are an effective way of killing tumour cells but have generally been avoided in curative treatment of patients because of concerns of a disproportionate increase in late normal tissue toxicity. Radiobiological modelling of the effect of radiation on lung tumours and late-reacting normal tissues, which are more sensitive to large radiation fractions, has been undertaken. The biological effect of radiation on tumours is increased as the overall treatment time is shortened but this is not true for late-reacting normal tissue. Sample data are shown in which the relative increases in radiation effect on the tumour and late-reacting normal tissues are similar after hypofractionation. A favourable therapeutic ratio can be achieved because the bulk of normal tissue will receive a lower dose of radiation at a lower dose per fraction than the tumour, especially with current techniques where the volume of normal tissue irradiated can be sharply reduced. The clinical evidence confirms that lung toxicity is volume-dependent. It is the small Stage I and II tumours which are most likely to benefit from hypofractionated regimens, as the volumes to be treated are smaller and they have a lower incidence of distant metastases. Patients with Stage III tumours with favourable prognostic factors are nowadays treated with combined chemotherapy and radiotherapy and so for this group more conservative hypofractionation regimens are being explored. However, more advanced tumours may be treated with hypofractionation to lower total doses to achieve palliation and a modest degree of survival benefit.     

Cetuximab combination with chemotherapy in advanced non-small cell lung cancer

Objective  

To observe the efficacy and safety of cetuximab combined with chemotherapy in advanced non-small-cell lung cancer (NSCLC), and to investigate the association of status of K-RAS gene mutation and epidermal growth factor receptor (EGFR) genotype with clinical outcome.     

Hypofractionated irradiation for inoperable non-small cell lung cancer

A policy of palliative intent thoracic irradiation was prospectively evaluated in 38 consecutive patients referred for treatment of inoperable non-small cell lung cancer at a single institution. A target dose of 1700cGy in two fractions 1 week apart was delivered. Characteristics of the treatment group revealed most (87%; 33/38) to be of good-excellent performance status with minimal weight loss before irradiation. Although three patients (8%) had initial metastatic disease, ail had symptoms referable to the thorax with cough (71%), dyspnoea (55%), haemoptysis (39%), and chest wall pain (34%) being dominant. Following treatment, the relative risk of maintaining complete response with regard to each of these symptoms was 0.91, 0.40, 0.92 and 0.78, respectively. Overall 70% of patients maintained complete symptomatic response to time of death or last review. Uncorrected median survival was 35 weeks and was comparable to best international end-results for either palliative intent or curative intent radiation schedules. We conclude that the radiation regimen employed is safe, efficacious and eminently resource conscious. Recognition of patient groups who overwhelmingly derive no benefit from conventional fractionation schedules will streamline access to radiotherapy services of patients suitable for radical treatment.     

Prophylactic cranial irradiation in non-small cell lung cancer]

Prophylactic cranial irradiation (PCI) has become part of the standard treatment in patients with small cell lung cancer (SCLC) in complete remission. Not only does it decrease the risk of brain recurrence by almost 50%, it has a significant positive effect on survival (5.4 percent increase at 3 years). As the prognosis of patients with locally advanced non-small cell lung cancer (NSCLC) has improved with combined modality treatment, brain metastases have also become an important cause of failure (10 to 30%, approaching 50% in certain studies as in SCLC). Survival after treatment of brain metastases is poor and impact on quality of life of patients is important. As in SCLC, 4 randomised evaluating PCI in NSCLC have been carried out in the seventies and early eighties. If 3 out of 4 trials have shown a significant decrease of brain metastases, none of them demonstrated any impact on survival. Thus PCI cannot be recommended as standard treatment in NSCLC, however new trials would be needed.     

MiR-195 suppresses non-small cell lung cancer by targeting CHEK1

MiR-195 suppresses tumor growth and is associated with better survival outcomes in several malignancies including non-small cell lung cancer (NSCLC). Our previous study showed high miR-195 plasma levels associated with favorable overall survival of non-smoking women with lung adenocarcinoma. To further elucidate role of miR-195 in NSCLC, we conducted in vitro experiment as well as clinical studies in a cohort of 299 NSCLC samples. We demonstrated that miR-195 expression was lower in tumor tissues and was associated with poor survival outcome. Overexpression of miR-195 suppressed tumor cell growth, migration and invasion. We discovered that CHEK1 was a direct target of miR-195, which decreased CHEK1 expression in lung cancer cells. High expression of CHEK1 in lung tumors was associated with poor overall survival. Our results suggest that miR-195 suppresses NSCLC and predicts lung cancer prognosis.     

Sequential combination of 5-fluorouracil, cis-platinum and irradiation in unresectable non-small cell lung cancer

Twenty patients with unresectable non-small cell lung carcinoma, 15 stage III and 5 stage IV (supraclavicular lymphadenopathy) were treated with a combination of three courses of chemotherapy and hypofractionated irradiation followed after 3 weeks by split-course radiotherapy. Each course was repeated every 3 weeks with the following sequence. Cis-platin (CDDP) (20 mg/m2) was given in a 20-min infusion, followed by a 2-h infusion of 5-fluorouracil (5-FU) (400 mg/m2) on days 1, 2, 5 and 6. Radiation with a dose of 3 Gy on the target volume was given on days 3 and 4, after a 2-h infusion of 5-FU (400 mg/m2). Split course of irradiation consisted of 16 Gy in 5 fractions repeated after 3 weeks interval. The objective response rate was 75%. Median follow-up was 24 months, the median survival was 14 months. The 1-year survival was 53% and the 2-year survival was 16%.     

非小细胞肺癌EGFR—TKI再治疗反应临床观察及机制探讨

目的：观察非小细胞肺癌（non-smallcelllungcancer,NSCLC）患者使用表皮生长因子受体酪氨酸激酶抑制剂（epidermalgrowthfactorreceptor_tyrosinekinaseinhibitor,EGFR-TKI）初始治疗失败后,经过一段时间的间歇期,再次应用EGFR—TKI治疗的临床疗效,并探讨其可能的分子机制。方法：回顾性分析2008—12-01—2012-05—30,我院19例初始用EGFR—TKI治疗失败后停止一段时间并再次应用EGFR-TKI治疗的NSCLC患者的临床资料。采用小剂量递增的方法,体外诱导EGFR-TKI耐药的细胞模型,研究“治疗再反应”现象可能的分子机制。结果：19例NSCLC患者中47．4％（9／19）再次应用EGFR-TKI仍可获得疾病控制,其中PR为15．8％（3／19）,SD为31．6％（6／19）。同时,体外诱导的耐药细胞株经顺铂治疗2个月后,再次给予厄洛替尼（Erlotinib）治疗,抑制率由3％升高至15％,P〈0．05,再次显示了部分的有效性。蛋白质印迹法检测自噬相关分子LC3B发现,耐药细胞株LC3B表达增加,再次Erlotinib治疗后LC3B表达水平相对未处理细胞明显下调。结论：EGFR-TKI治疗失败的NSCLC患者经过一段时间的间歇期再次应用EGFR—TKI,部分患者仍可获得较满意的疾病控制,该效应可能与细胞自噬有密切关系,这种再治疗反应有望成为NSCLC的一种有效治疗策略。     

miR-1238 inhibits cell proliferation by targeting LHX2 in non-small cell lung cancer

In human cancers, dysregulated expression of LIM-homeobox gene 2 (LHX2) and downregulation of miR-1238 has been reported separately. However, the relationship between them remains unclear. We investigated the functional contribution of miR-1238 to the regulation of LHX2 in non-small cell lung cancer (NSCLC). Here, computational algorithms predicted that the 3′-untranslated region (3′-UTR) of LHX2 is a target of miR-1238. Luciferase assays validated that miR-1238 directly bound to 3′-UTR of LHX2. qRT-PCR and western blot analyses further confirmed that overexpression of miR-1238 mimic in NSCLC A549 and LTEP-α-2 cells inhibited endogenous expression of LHX2 mRNA and protein. Moreover, ectopic expression of miR-1238 in NSCLC A549 and LTEP-α-2 cells suppressed cellular viability and proliferation. siRNA-induced knockdown of LHX2 copied the phenotype of miR-1238 overexpression in NSCLC A549 and LTEP-α-2 cells and LHX2 knockdown inhibited cell cycle. In addition, miR-1238 expression was frequently decreased in human NSCLC tissues and reversely correlated with LHX2 expression, which was increased in NSCLC tissues. Collectively, our findings demonstrate that miR-1238 inhibit the proliferation of NSCLC cells at least partly via repression of LHX2, shedding light on the mechanistic interaction of miR-1238 and LHX2 in NSCLC carcinogenesis. Furthermore, our data suggest that expression of miR-1238 could be a promising therapeutic strategy for NSCLC treatment.     

MicroRNA-451 functions as a tumor suppressor in human non-small cell lung cancer by targeting ras-related protein 14 (RAB14)

Accumulating evidence suggests that microRNAs (miRNAs) are important gene regulators, which can have critical roles in diverse biological processes including tumorigenesis. In this study, we analyzed the miRNA expression profiles in non-small cell lung carcinoma (NSCLC) by use of a miRNA microarray platform and identified 40 differentially expressed miRNAs. We showed that miRNA (miR)-451 was the most downregulated in NSCLC tissues. The expression level of miR-451 was found to be significantly correlated with tumor differentiation, pathological stage and lymph-node metastasis. Moreover, low miR-451 expression level was also correlated with shorter overall survival of NSCLC patients (P<0.001). Ectopic miR-451 expression significantly suppressed the in vitro proliferation and colony formation of NSCLC cells and the development of tumors in nude mice by enhancing apoptosis, which might be associated with inactivation of Akt signaling pathway. Interestingly, ectopic miR-451 expression could significantly inhibit RAB14 protein expression and decrease a luciferase-reporter activity containing the RAB14 3'-untranslated region (UTR). In addition,, RNA interference silencing of RAB14 gene could recapitulate the tumor suppressor function of miR-451, whereas restoration of RAB14 expression could partially attenuate the tumor suppressor function of miR-451 in NSCLC cells. Furthermore, we also showed that strong positive immunoreactivity of RAB14 protein was significantly associated with downregulation of miR-451 (P=0.01). These findings suggest that miR-451 regulates survival of NSCLC cells partially through the downregulation of RAB14. Therefore, targeting with the miR-451/RAB14 interaction might serve as a novel therapeutic application to treat NSCLC patients.     

Prophylactic cranial irradiation for limited non-small cell lung cancer

Seventy-three patients with biopsy-proven limited non-small cell lung cancer (NSCLC) were entered on a combined modality study at the University of Washington. Seventy-five percent (55 of 73) of the patients had a histologic diagnosis of adenocarcinoma or large cell carcinoma, whereas 25% (18 of 73) had squamous cell carcinoma. After two cycles of chemotherapy, patients without evidence of progressive disease received prophylactic cranial irradiation (PCI) and chest radiotherapy, followed by two additional cycles of chemotherapy. Brain computed tomography (CT) scans were performed at 3-month intervals after completion of therapy in all patients, and were additionally performed whenever signs or symptoms developed suggesting neurologic dysfunction or recurrent brain disease. Sixty-five patients were treated with PCI. No clinical or CT evidence of recurrence in the brain has developed in patients who completed PCI. PCI appears to be effective in greatly reducing the incidence of brain relapse in patients with limited NSCLC.     

Concurrent chemotherapy and thoracic irradiation in non-small cell lung cancer

Do results from recently reported phase II trials of combination chemotherapy and concurrent radiation warrant evaluation in a randomized study? Our bias is that only treatment regimens associated with a twofold increase in median survival should be considered for a phase III trial increase in median survival. Therefore, for stage IIIA N2 NSCLC patients median survival should increase from 12 to 24 months, and for stage IIIB patients, it should increase from 9 to 18 months. Although survival results from some combined modality trials are encouraging, thus far no concurrent chemotherapy-radiation regimen appears to have produced the preceding results.     

Fas蛋白与非小细胞肺癌关系的研究进展

With the rapid growth of incidence of non-small cell lung cancer (NSCLC), more and more studies have been made about its occurrence, development and metastatic mechanism in recent years. Researches about Fas/FasL protein expression and Fas/FasL-mediated apoptosis, immune escape mechanism and their roles in the pathogenesis, progression and prognosis of lung cancer are constantly emerging. Discussion about the roles of Fas/ FasL system in NSCLC could provide evidence for early diagnosis, prognosis prediction and new treatment of NSCLC.     

Cisplatin schedule in combination with gemcitabine in unresectable non-small cell lung cancer

Gemcitabine (on days 1, 8, and 15)-cisplatin (on day 15) combinations were used to treat 9 patients with unresectable non-small cell lung cancer to study efficacy and safety. Gemcitabine 1,000 mg/m2 was administered on days 1, 8, and 15 of a 28-day cycle. Cisplatin 60-65 mg/m2 was administered on day 15 of a 28-day cycle. Three cycles were planned per patient. The nine patients received 25 cycles of chemotherapy. Objective response rates was 55% (complete response 11% and partial response 44%). Stable disease was 33%, and progressive disease was 11%. Seven of 9 patients received the planned 3 cycles of therapy. Two patients received only 2 cycles, due to progressive disease (1 patient), and ulcerative colitis (1 patient). Grade 3 leukopenia was 22%, and grade 3 neutropenia was 11%. No grade 4 hematological toxicities were observed. Grade 3 anorexia was 11%, and grade 3 skin rash which occurred in the first cycle 22%. Our data show less toxicity and no significant difference in response rates, so the administration of cisplatin on day 15 seemed to be a useful and safe regimen.     

尼妥珠单抗联合化疗治疗晚期非小细胞肺癌

目的 评价尼妥珠单抗联合化疗治疗晚期非小细胞肺癌(NSCLC)的价值.方法 回顾性分析2009年1月至2010年10月采用尼妥珠单抗联合化疗的37例晚期NSCLC患者的临床资料.其中Ⅲb期12例,Ⅳ期25例.采用尼妥珠单抗联合铂类为基础的化疗方案24例,尼妥珠单抗联合非铂类药物的化疗方案13例.尼妥珠单抗联合化疗作为一线方案患者10例,二线方案23例,三线方案4例.结果 37例患者共计化疗137个周期,平均每例3.7个周期.其中完全缓解(CR)1例,部分缓解(PR)9例,稳定(SD)16例,进展(PD)11例,有效率(RR)为27.0%,临床获益率(CBR)为70.3%.主要毒副反应为骨髓抑制和胃肠道反应,仅有1例患者出了Ⅰ度座疮样皮疹.结论 尼妥珠单抗联合化疗治疗晚期NSCLC患者可提高疗效,且耐受性良好.

Abstract：

Objective To evaluate the role of nimotuzumab in combination with chemotherapy in patients with advanced non-small cell lung cancer (NSCLC). Methods The clinical data of 37 NSCLC patients who received nimotuzumab in combination with chemotherapy in Tianjin Medical University Cancer Hospital from January 2009 to October 2010 were retrospectively reviewed. Of the thirty-seven patients, 12patients were in stage Ⅲ B, 25 patients in stage Ⅳ. Twenty-four patients recived platinum-based chemotherapy in combination with nimotuzumab, 13 patients recived nonplatinum-based chemotherapy in combination with nimotuzumab. Ten patients received nimotuzumab in combination with chemotherapy as first-line regimen, 23 patients as second-line regimen, 4 patients as third-line regimen. Results Of the 37advanced NSCLC patients who received nimotuzumab in combination with chemotherapy, the total number ofchemotherapy were 137 cycles, the mean number was 3.7 cycles. One patient had complete remission (CR), 9 patients had partial remission (PR), 16 cases had stable disease (SD), and 11 patients hadprogressive disease (PD). The response rate (RR) was 27% and clinical benefit rate (CBR) was 70.3%.The main side effects were bone marrow suppression and gastrointestinal reactions. Grade I acneiform rash was found in one patient. Conclusion The regimen of nimotuzumab in combination with chemotherapy can improve the response rate and was well tolerated in patients with advanced non-small cell lung cancer.