The nonsmokers’ and smokers’ pathways in lung adenocarcinoma: Histological progression and molecular bases

There could be two carcinogenetic pathways for lung adenocarcinoma (LADC): the nonsmokers’ pathway and the smokers’ pathway. This review article describes the two pathways with special reference to potential relationships between histological subtypes, malignant grades, and driver mutations. The lung is composed of two different tissue units, the terminal respiratory unit (TRU) and the central airway compartment (CAC). In the nonsmokers’ pathway, LADCs develop from the TRU, and their histological appearances change from lepidic to micropapillary during the progression process. In the smokers’ pathway, LADCs develop from either the TRU or the CAC, and their histological appearances vary among cases in the middle of the progression process, but they are likely converged to acinar/solid at the end. On a molecular genetic level, the nonsmokers’ pathway is mostly driven by EGFR mutations, whereas in the smokers’ pathway, approximately one-quarter of LADCs have KRAS mutations, but the other three-quarters have no known driver mutations. p53 mutations are an important factor triggering the progression of both pathways, with unique molecular alterations associated with each, such as MUC21 expression and chromosome 12p13-21 amplification in the nonsmokers’ pathway, and HNF4α expression and TTF1 mutations in the smokers’ pathway. However, investigation into the relationship between histological progression and genetic alterations is in its infancy. Tight cooperation between traditional histopathological examinations and recent molecular genetics can provide valuable insight to better understand the nature of LADCs.     

Development of an optimal protocol for molecular profiling of tumor cells in pleural effusions at single-cell level

Liquid biopsy analyzes the current status of primary tumors and their metastatic regions. We aimed to develop an optimized protocol for single-cell sequencing of floating tumor cells (FTCs) in pleural effusion as a laboratory test. FTCs were enriched using a negative selection of white blood cells by a magnetic-activated cell sorting system, and CD45-negative and cytokeratin-positive selection using a microfluidic cell separation system with a dielectrophoretic array. The enriched tumor cells were subjected to whole-genome amplification (WGA) followed by genome sequencing. The FTC analysis detected an EGFR exon 19 deletion in Case 1 (12/19 cells, 63.2%), and EML4-ALK fusion (17/20 cells, 85%) with an alectinib-resistant mutation of ALK (p.G1202R) in Case 2. To eliminate WGA-associated errors and increase the uniformity of the WGA product, the protocol was revised to sequence multiple single FTCs individually. An analytical pipeline, accurate single-cell mutation detector (ASMD), was developed to identify somatic mutations of FTCs. The large numbers of WGA-associated errors were cleaned up, and the somatic mutations detected in FTCs by ASMD were concordant with those found in tissue specimens. This protocol is applicable to circulating tumor cells analysis of peripheral blood and expands the possibility of utilizing molecular profiling of cancers.     

Conditional Ror1 knockout reveals crucial involvement in lung adenocarcinoma development and identifies novel HIF-1α regulator

We previously reported that ROR1 is a crucial downstream gene for the TTF-1/NKX2-1 lineage-survival oncogene in lung adenocarcinoma, while others have found altered expression of ROR1 in multiple cancer types. Accumulated evidence therefore indicates ROR1 as an attractive molecular target, though it has yet to be determined whether targeting Ror1 can inhibit tumor development and growth in vivo. To this end, genetically engineered mice carrying homozygously floxed Ror1 alleles and an SP-C promoter–driven human mutant EGFR transgene were generated. Ror1 ablation resulted in marked retardation of tumor development and progression in association with reduced malignant characteristics and significantly better survival. Interestingly, gene set enrichment analysis identified a hypoxia-induced gene set (HALLMARK_HYPOXIA) as most significantly downregulated by Ror1 ablation in vivo, which led to findings showing that ROR1 knockdown diminished HIF-1α expression under normoxia and clearly hampered HIF-1α induction in response to hypoxia in human lung adenocarcinoma cell lines. The present results directly demonstrate the importance of Ror1 for in vivo development and progression of lung adenocarcinoma, and also identify Ror1 as a novel regulator of Hif-1α. Thus, a future study aimed at the development of a novel therapeutic targeting ROR1 for treatment of solid tumors such as seen in lung cancer, which are frequently accompanied with a hypoxic tumor microenvironment, is warranted.     

驱动基因阴性肺腺癌化疗前后外周血有核细胞中STAT3、UCH37水平变化与化疗疗效的关系

目的:探讨驱动基因阴性晚期肺腺癌患者外周血有核细胞中信号转导和转录激活因子3（STAT3）、泛素化羧基末端水解酶37（UCH37）表达水平变化与化疗疗效的关系。方法:选取2018年06月至2019年08月衡水市人民医院收治的晚期非手术驱动基因阴性接受化疗的肺腺癌患者150例(肺癌组),均给予标准培美曲塞+顺铂方案化疗,同期选取体检中心健康体检者50名(健康组),实时定量PCR(qRT-PCR)技术检测2组外周血有核细胞中STAT3、UCH37水平,分析 STAT3、UCH37水平与化疗疗效的关系。结果:化疗前肺癌组外周血STAT3、UCH37表达水平明显高于健康组,差异有统计学意义(P＜0.05);肺癌组化疗有效率为57.3%。有效组化疗后外周血有核细胞中STAT3、 UCH37水平较化疗前明显降低,差异有统计学意义(P＜0.05)。与无效组相比,有效组化疗后外周血有核细胞中STAT3、UCH37水平明显降低,差异有统计学意义(P＜0.05)。ROC曲线分析结果显示,STAT3评估肺癌化疗有效的敏感度为83.72%,特异度为84.38%,准确度为84.00%;UCH37评估肺癌化疗有效的敏感度为80.23%,特异度为78.13%,准确度为79.30%;STAT3联合UCH37评估肺癌化疗有效的敏感度为95.35%,特异度为92.19%,准确度为94.00%,均明显高于单独检测,差异有统计学意义(P＜0.05)。结论:STAT3、UCH37在肺腺癌患者外周血有核细胞中的表达水平明显高于健康人群,提示这两种基因在肺腺癌的发生发展过程中起到促进作用。肺腺癌患者化疗前后外周血有核细胞中STAT3、UCH37水平变化与疗效有关,STAT3、UCH37可作为预测化疗效果的重要指标,且二者联合检测具有更高的参考价值。     

Proteins of the retinoblastoma pathway,FEN1 and MGMT are novel potential prognostic biomarkers in pancreatic adenocarcinoma

Background

We studied the expression of some major proteins involved in cell-cycle regulation and DNA repair, the roles of which are not well known in pancreatic ductal adenocarcinoma (PDAC), but which have a significant impact on carcinogenesis of many other cancers.

High PITX1 expression in lung adenocarcinoma patients is associated with DNA methylation and poor prognosis

Background

Pituitary homeobox 1 (PITX1) is a member of the PITX gene family which is vital to proper development of early embryo. However, the relationship of PITX1 expression and overall survival (OS) in non-small cell lung cancer (NSCLC) is not clear.

miR-24对肺癌A549细胞化疗敏感性的影响

目的:探究微小RNA(miR)-24对肺癌细胞A549化疗敏感性的影响及可能的作用机制。方法:Real-time PCR实验检测肺腺癌细胞系A549及肺腺癌耐药细胞株A549/DDP中miR-24的表达情况。转染miR-24抑制序列(miR-24 inhibitor)下调A549/DDP细胞中的miR-24后,采用CCK-8法检测细胞活力,流式细胞术检测细胞凋亡,Western blot检测Bcl-2、Bax、cleaved caspase-3、cleaved caspase-9、细胞色素C(Cyt C)、磷酸化细胞外信号调节激酶(p-ERK)和P53的蛋白水平。双荧光素酶报告基因实验预测及验证miR-24可能的靶基因。结果:耐药细胞株A549/DDP中miR-24的表达水平明显高于A549细胞(P0.05)。miR-24 inhibitor可诱导肺腺癌耐药细胞株A549/DDP的凋亡,增加细胞对顺铂的敏感性;此外还可下调Bcl-2/Bax比值,同时上调P53、p-ERK、cleaved caspase-9、cleaved caspase-3及Cyt C的蛋白水平。而应用ERK特异性抑制剂U0126可部分恢复miR-24 inhibitor转染的细胞活力。生物信息学分析显示p53是miR-24的可能作用靶点基因,在A549/DDP细胞中共转染miR-24 inhibitor和P53 siRNA可部分逆转miR-24 inhibitor对细胞活力的影响。结论:下调肺腺癌耐药细胞株A549/DDP中miR-24的表达可增加细胞对顺铂的敏感性,其机制可能与靶向p53基因同时激活ERK/P53信号通路后促进细胞经线粒体途径的凋亡有关。     

Hereditary gastrointestinal carcinomas and their precursors: An algorithm for genetic testing

Recognition of hereditary forms of gastrointestinal cancer is of great importance for patients and their families and pathologists play a crucial role in this. This review recapitulates the clinical, pathological and molecular aspects of Hereditary Diffuse Gastric Cancer and Gastric Adenocarcinoma and Proximal Polyposis of the Stomach, as well as hereditary colorectal cancer syndromes such as Lynch syndrome and gastrointestinal polyposis syndromes (including Familial Adenomatous Polyposis, Peutz-Jeghers syndrome and Juvenile Polyposis syndrome). Histopathological clues to recognize hereditary forms of gastrointestinal cancer and possible ancillary studies that can support an underlying syndrome and guide genetic testing are discussed.     

SOCS4在肺腺癌细胞增殖和侵袭中的作用

目的探讨细胞因子信号抑制分子-4(SOCS4)对肺腺癌细胞生物学行为的影响及作用机制。方法采用基因干扰技术,用脂质体法转染SOCS4基因的干扰质粒到肺腺癌细胞系SPC-A1和A549中。CCK-8细胞增殖实验和Transwell实验分别检测SOCS4对肺腺癌细胞增殖和侵袭能力的影响,并通过western blot检测EGFR(表皮细胞因子受体)及其下游的磷酸化STAT3(p-STAT3,磷酸化的信号转导子与转录激活子)蛋白的表达水平。结果 CCK-8实验结果表明,SOCS4表达下调后,SPC-A1和A549细胞在第48、72、96和120 h的增殖能力均高于对照组(P均0.05);Transwell实验结果显示,干扰组细胞侵袭的数量明显高于对照组(t=11.62,P0.01;t=11.93,P0.01)。western blot结果表明,干扰SOCS4表达能上调EGFR及其p-STAT3的表达。结论 SOCS4可能通过抑制EGFR表达并阻碍其下游的STAT3磷酸化,抑制肺腺癌细胞的增殖和侵袭。     

食管胃结合部腺癌患者行微创手术中淋巴结的清扫效果

目的探讨腹腔镜下行食管胃结合部腺癌(AEG)根治术中淋巴结的清扫效果。方法选取2014年6月-2015年9月该院收治的105例行开腹或腹腔镜根治术的AEG患者为研究对象,根据手术方式分为微创组(n=70)和开腹组(n=35),比较两组的基线资料、淋巴结清扫结果及围手术期资料。结果微创组的脾门淋巴结清扫总数明显多于开腹组(P0.05)。两组的术中淋巴结清扫总数、阳性数目、阳性患者例数、脾门淋巴结阳性数目和阳性患者例数等比较,差异无统计学意义(P0.05)。微创组的手术时间、术中失血量、切口长度、近端切缘阳性率、胸腹部联合切除率和脾切除率等均明显低于开腹组,近端食管切除长度明显大于开腹组(P0.05)。所有患者术后均未出现死亡,微创组的首次排气时间、首次下床时间、首次进流质时间等均明显低于开腹组(P0.05)。两组的并发症发生率比较,差异无统计学意义(P0.05)。结论与开腹手术相比,腹腔镜AEG根治术在清扫脾门淋巴结方面较有一定优势,且切除的食管更长,胸腹部联合切除率与脾切除率更低,安全可行,值得临床推广应用。