Cancer stem cell-related marker expression in lung adenocarcinoma and relevance of histologic subtypes based on IASLC/ATS/ERS classification

ALDH1A1 induces resistance to CHOP in diffuse large B-cell lymphoma through activation of the JAK2/STAT3 pathway

Increasing evidence has shown that aldehyde dehydrogenase 1A1 (ALDH1A1), a detoxifying enzyme, is responsible for chemoresistance in a variety of tumors. Although the majority of patients with diffuse large B-cell lymphoma (DLBCL) can be cured with cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), chemoresistance is a common cause of treatment failure. This study aims to investigate the significance of ALDH1A1 expression and the mechanism by which ALDH1A1 is involved in the chemoresistance of DLBCL cells. ALDH1A1 expression was assessed in 88 DLBCL tissues by immunohistochemistry. The association between ALDH1A1 expression and outcome was evaluated. We also investigated the effect of ALDH1A1 on CHOP resistance in DLBCL cells using functional analysis. ALDH1A1 expression levels were upregulated in patients with stable or progressive disease after CHOP and its expression positively correlated with expression of STAT3 and p-STAT3. In keeping with these observations, ALDH1A1 expression was significantly associated with short survival of DLBCL patients who received CHOP chemotherapy. In functional assays in Pfeiffer cells, overexpression of ALDH1A1 conferred resistance to CHOP, while silencing of ALDH1A1 using short hairpin RNA had the opposite effect. Furthermore, we also observed that ALDH1A1 could regulate the JAK2/STAT3 pathway, while inhibition of the JAK2/STAT3 pathway by WP1066 negated the effect of ALDH1A1 overexpression. These observations reveal that ALDH1A1 induces resistance to CHOP through activation of the JAK2/STAT3 pathway in DLBCL, and its targeting provides a potential strategic approach for reversing CHOP resistance.

Association between the histological subtype of lung adenocarcinoma, EGFR/KRAS mutation status and the ALK rearrangement according to the novel IASLC/ATS/ERS classification

The present study aimed to investigate the association between epidermal growth factor receptor (EGFR)/Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations, anaplastic lymphoma receptor tyrosine kinase (ALK) rearrangements and the morphological characteristics of lung adenocarcinoma (LAC), according to the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society (IASLC/ATS/ERS) classification in a large group of patients with primary LAC. A total of 200 patients with invasive LAC who had undergone complete resections at the Beijing Chest Hospital (Beijing, China) were randomly selected. The morphology of the samples was reassessed in 5% increments by two pathologists, according to the IASLC/ATS/ERS scheme. EGFR and KRAS mutations were tested by direct DNA sequencing. ALK rearrangements were screened by immunohistochemistry on a Benchmark XT stainer. The data revealed that EGFR and KRAS mutations, and ALK rearrangements were identified in 46.0% (92/200), 9.0% (18/200) and 11.5% (23/200) of the patients, respectively. The EGFR/KRAS mutations and ALK rearrangements were mostly exclusive. However, 1 patient exhibited the coexistence of the EGFR (at exon 20) and KRAS (codon 12) mutations, and another patient exhibited the coexistence of the EGFR mutation (at exon 21) and the ALK gene fusion. EGFR mutations were indicated to be closely associated with the acinar predominant (43/77; 55.8%; P=0.030) and papillary predominant (26/49; 53.1%; P=0.006) subtypes. KRAS mutations were more commonly associated with the solid predominant subtype (9/52; 17.3%; P=0.023) and invasive mucinous LAC (5/10; 50.0%; P=0.004), and less commonly associated with the acinar predominant subtype (1/77; 1.3%; P=0.002). ALK rearrangements more commonly occurred in the solid predominant subtype compared with other subtypes (13/52; 25%; P=0.002), and less commonly occurred in the papillary predominant subtype (1/49; 2.0%; P=0.004). Tumors harboring ALK rearrangements were characterized by signet-ring cell (7/9; 77.8%; P<0.0001) and cribriform (7/12; 58.3%; P<0.0001) patterns. The association between the mutation status and histological subtype in LAC was distinct. The predominant subtype according to the IASLC/ATS/ERS classification provided important information for gene mutations and integrated clinical findings to improve the treatment of LAC patients.

Clinicopathological and prognostic significance of metastasis-associated protein 1 expression and its correlation with angiogenesis in lung invasive adenocarcinomas, based on the 2011 IASLC/ATS/ERS classification

Based on previous findings regarding the angiogenic activities and prognostic roles of metastasis-associated protein 1 (MTA1) in early-stage non-small cell lung cancer, the clinicopathological and prognostic significance of MTA1 protein expression, and its correlation with angiogenesis in lung invasive adenocarcinoma, were further assessed in the present study, according to the 2011 International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification. High protein expression levels of MTA1 were commonly observed in patients with lung invasive adenocarcinoma, and were significantly correlated with tumor size (P=0.030), lymph node metastasis (P=0.021) and microvessel density (P=0.015). Survival analysis demonstrated that patients with high protein expression levels of MTA1 exhibited significantly shorter five-year disease-free and overall survival than those patients whose protein expression levels of MTA1 were low (24.5% vs. 48.7%, P=0.001, and 34.7% vs. 59.2%, P=0.005, respectively). In addition, Cox regression multivariate analysis demonstrated that high protein expression levels of MTA1 significantly correlated with unfavorable five-year disease-free survival (P=0.024). These findings indicate that MTA1 protein expression may possess clinical potential as an indicator of progressive phenotype. Therefore, MTA1 is a promising prognostic predictor to identify subgroups of patients with high risk of relapse, and a potentially novel therapeutic target for antiangiogenesis in patients with lung invasive adenocarcinoma.

Variation in the expression levels of predictive chemotherapy biomarkers in histological subtypes of lung adenocarcinoma: an immunohistochemical study of tissue samples

BACKGROUND

Lung adenocarcinoma is often composed of a complex and heterogeneous mixture of histological subtypes. Invasive adenocarcinomas are now classified by their predominant pattern, using the comprehensive histological subtyping of the International Association for the Study of Lung Cancer (IASLC), the American Thoracic Society (ATS), and the European Respiratory Society (ERS) classifications. This study aimed to determine whether the expression levels of predictive chemotherapy biomarkers are associated with the histological subtypes proposed by the IASLC/ATS/ERS classification.

MATERIALS AND METHODS

We reviewed data on representative tissue samples from 27 patients who received surgical resection and the expression of excision repair cross complementation group 1 (ERCC1), class III β-tubulin, thymidylate synthase (TS), ribonucleotide reductase M1 (RRM1), and c-Met were examined using immunostaining on tumor tissue slides. We assessed immunohistochemical H-scores, as calculated from the intensity and distribution of intratumor expression, according to the IASLC/ATS/ERS histological subtype.

RESULTS

The expression levels of predictive chemotherapy biomarkers varied according to histological subtype. The H-scores of TS and class III β-tubulin expression levels were higher in solid-type components than they were in lepidic-type components Tumors with solid predominant histology tended to recur earlier than non-solid predominant tumors. However, none of the H-scores in histologically predominant tissues was significantly associated with staging or overall survival.

CONCLUSIONS

Immunohistochemical H-scores of the predictive chemotherapy biomarkers were strongly associated with histological subtype. The presence of a solid subtype, which was associated with poor outcomes, might be assessed by measuring these biomarkers in mixed subtype adenocarcinomas.

[The research of clinical pathological features of ALK positive lung cancer in 525 patients and the discussion of detection methods]

BACKGROUND

The fusion (rearrangement) of anaplastic lymphoma kinase (ALK) gene has been identified as an import factor to the tumorigenesis and development of lung cancer. ALK tyrosine kinase inhibitors (ALK-TKIs) have been proved to have good effects to ALK positive lung cancers. The increasement of the relevance ratio of ALK will be very important to patients. The aim of this study is to investigate the clinical pathological features of ALK positive lung cancer, and the roles of immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) in screening and confirming the ALK positive cases in the testing flow of ALK.

METHODS

IHC analysis of ALK in tumor specimens was performed on 525 lung cancer patients. 34 cases among them were confirmed by FISH.

RESULTS

The positive incidence of ALK by IHC was 5.14% (27/525). The ALK positive patients were significantly younger than ALK negative patients (P<0.05), and femal was predominant (P<0.05). The proportion of solid predominant adenocarcinoma was significantly higher in ALK positive patients (P<0.05). While acinar and lepidic predominant adenocarcinoma were significantly lower in ALK positive patients (P<0.05). FISH was applied in 34 cases. The coincidence rate was increased with the increasement of positive intensity of IHC staining. All the IHC positive cases with or without EGFR mutation must be confirmed by FISH.

CONCLUSIONS

IHC is a reliable detection method to screening the ALK in lung cancer, and then enhance the relevance ration. To make a definite diagnosis of ALK positive lung cancer, FISH is a significant detection method.

Enhanced expression of long non-coding RNA ZXF1 promoted the invasion and metastasis in lung adenocarcinoma

The identification of cancer-associated long non-coding RNAs (LncRNA) and the investigation of their molecular and biological functions are important for understanding the molecular biology and progression of cancer. This study aims to find the key LncRNA associated with lung adenocarcinoma and to evaluate its biological role and clinical significance in tumor progression. Microarray analysis of 32,756 LncRNA was performed to screen the significantly different LncRNA between human lung adenocarcinoma tissues and adjacent non-cancerous lung tissues, which was named as LncRNA ZXF1. Expression of LncRNA ZXF1 was analyzed in 62 lung adenocarcinoma tissues and adjacent non-cancerous lung tissues by quantitative reverse-transcription PCR (qRT-PCR). Correlations between LncRNA ZXF1 expression and the clinicopathological features and prognosis of patients were also analyzed. The inhibition of LncRNA ZXF1 using siRNA treatment was performed in order to explore its role in tumor progression. The effect of LncRNA ZXF1 on proliferation was evaluated by CCK-8 assay using A549 cell lines, and cell migration and invasion were detected by transwell assays. Here we found that LncRNA ZXF1 levels were remarkably increased in lung adenocarcinoma tissues compared with adjacent non-cancerous lung tissues (P<0.05), and up-regulated LncRNA ZXF1 was correlated with lymph node metastasis (P<0.05), tumor pathological stage (P<0.05) and the extent of lymph node metastasis (correlation coefficient=0.366). The 3-year overall survival rate of patients with higher LncRNA ZXF1 levels was remarkably reduced compared with patients with lower LncRNA ZXF1 levels, implying that patients with high levels of LncRNA ZXF1expression had a relatively poor prognosis. Inhibition of LncRNA ZXF1 by siRNA decreased the migration and invasion of A549 cells in vitro, while there was no significant effect in cell proliferation.