PTEN and PIK3CA gene copy numbers and poor outcomes in non-small cell lung cancer patients with gefitinib therapy

Exploring the mechanism of aidi injection for lung cancer by network pharmacology approach and molecular docking validation

Background. Aidi injection (ADI) is an effective Traditional Chinese medicine preparation widely used for lung cancer. However, the pharmacological mechanisms of ADI on lung cancer remain to be elucidated. Methods. A network pharmacology (NP)-based approach and the molecular docking validation were conducted to explore underlying mechanisms of ADI on lung cancer. The compounds and target genes were screened by Traditional Chinese Medicine Systems Pharmacology (TCMSP) database and Bioinformatics Analysis Tool for Molecular mechANism of Traditional Chinese Medicine (Batman-TCM) database. The STRING database was utilized for protein interaction network construction. The R package clusterProfiler was used for bioinformatics annotation of hub target genes. The gene expression analysis and survival analysis were performed based on The Cancer Genome Atlas (TCGA) database. The Autodock Vina was used for molecular docking validation. Results. A total of five key compounds with 324 putative target genes were screened out, and 14 hub target genes were identified for treating lung cancer. Six hub genes could influence the survival of non-small cell lung cancer (NSCLC) patients. Of these hub genes, the expression pattern of EGFR, MYC, PIK3CA, and SMAD3 were significantly higher in the LUSC, while PIK3CA and RELA expressed lower in the LUAD group and LUSC group, respectively. These six hub genes had good docking affinity with the key compounds of ADI. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that ADI may exert therapeutic effects on lung cancer by regulating critical pathways including the thyroid hormone signaling pathway, MAPK signaling pathway, and PI3K-Akt signaling pathway. Conclusions. The present study explored the potential pharmacological mechanisms of ADI on lung cancer, promoting the clinical application of ADI in treating lung cancer, and providing references for advanced researches.

Mechanisms of resistance to irreversible epidermal growth factor receptor tyrosine kinase inhibitors and therapeutic strategies in non-small cell lung cancer

Epidermal growth factor receptor (EGFR) T790M mutation is the most frequent mechanism which accounts for about 60% of acquired resistance to first-generation EGFR tyrosine kinase inhibitors (TKIs) in non-small cell lung cancer (NSCLC) patients harboring EGFR activating mutations. Irreversible EGFR-TKIs which include the second-generation and third-generation EGFR-TKIs are developed to overcome T790M mediated resistance. The second-generation EGFR-TKIs inhibit the wide type (WT) EGFR combined with dose-limiting toxicity which limits its application in clinics, while the development of third-generation EGFR-TKIs brings inspiring efficacy either in vitro or in vivo. The acquired resistance, however, will also occur and limit their response. Understanding the mechanisms of resistance to irreversible EGFR-TKIs plays an important role in the choice of subsequent treatment. In this review, we show the currently known mechanisms of resistance which can be summarized as EGFR dependent and independent mechanisms and potential therapeutic strategies to irreversible EGFR-TKIs.

Reduced expression levels of PTEN are associated with decreased sensitivity of HCC827 cells to icotinib

The clinical resistance of non-small cell lung cancer (NSCLC) to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) has been linked to EGFR T790M resistance mutations or MET amplifications. Additional mechanisms underlying EGFR-TKI drug resistance remain unclear. The present study demonstrated that icotinib significantly inhibited the proliferation and increased the apoptosis rate of HCC827 cells; the cellular mRNA and protein expression levels of phosphatase and tensin homolog (PTEN) were also significantly downregulated. To investigate the effect of PTEN expression levels on the sensitivity of HCC827 cells to icotinib, PTEN expression was silenced using a PTEN-specific small interfering RNA. The current study identified that the downregulation of PTEN expression levels may promote cellular proliferation in addition to decreasing the apoptosis of HCC827 cells, and may reduce the sensitivity of HCC827 cells to icotinib. These results suggested that reduced PTEN expression levels were associated with the decreased sensitivity of HCC827 cells to icotinib. Furthermore, PTEN expression levels may be a useful marker for predicting icotinib resistance and elucidating the resistance mechanisms underlying EGFR-mutated NSCLC.

MET and PTEN gene copy numbers and Ki-67 protein expression associate with pathologic complete response in ERBB2-positive breast carcinoma patients treated with neoadjuvant trastuzumab-based therapy

Background

Pathologic complete response (pCR) after neoadjuvant chemotherapy for breast cancer is associated with improved prognosis in aggressive tumor subtypes, including ERBB2- positive tumors. Recent adoption of pCR as a surrogate endpoint for clinical trials in early stage breast cancer in the neoadjuvant setting highlights the need for biomarkers that, alone or in combination, help predict the likelihood of response to treatment.

Methods

Biopsy specimens from 29 patients with invasive ductal carcinoma treated with trastuzumab-based therapy prior to definitive resection and pathologic staging were evaluated by dual color bright field in situ hybridization (dual ISH) using probes for MET, TOP2A, PTEN, and PIK3CA genes, each paired with centromeric probes to their respective chromosomes (chromosomes 7, 17, 10, and 3). Ki-67 expression was assessed by immunohistochemistry (IHC). Various parameters describing copy number alterations were evaluated for each gene and centromere probe to identify the optimal parameters for clinical relevance. Combinations of ISH parameters and IHC expression for Ki-67 were also evaluated.

Results

Of the four genes and their respective chromosomes evaluated by ISH, two gene copy number parameters provided statistically significant associations with pCR: MET gain or loss relative to chromosome 7 (AUC = 0.791, sensitivity = 92 % and specificity = 67 % at optimal cutoff, p = 0.0032) and gain of PTEN (AUC = 0.674, sensitivity = 38 % and specificity = 100 % at optimal cutoff, p = 0.039). Ki-67 expression was also found to associate significantly with pCR (AUC = 0.726, sensitivity = 100 % and specificity = 42 % at optimal cutoff, p = 0.0098). Combining gain or loss of MET relative to chromosome 7 with Ki-67 expression further improved the association with pCR (AUC = 0.847, sensitivity = 92 % and specificity = 83 % at optimal cutoffs, p = 0.0006).

Conclusions

An immunogenotypic signature of low complexity comprising MET relative copy number and Ki-67 expression generated by dual ISH and IHC may help predict pCR in ERBB2-positive breast cancer treated with neoadjuvant chemotherapy and trastuzumab. These findings require validation in additional patient cohorts.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2743-x) contains supplementary material, which is available to authorized users.

EGFR protein expression using a specific intracellular domain antibody and PTEN and clinical outcomes in squamous cell lung cancer patients with EGFR-tyrosine kinase inhibitor therapy

Purpose

The aim of this research was to examine the molecular and clinical features that are related with EGFR-tyrosine kinase inhibitor (EGFR-TKI) efficacy in previously treated patients with squamous cell carcinoma of the lung (SCCL).

Materials and methods

This retrospective study included 67 SCCL patients with obtainable lung cancer tissue and records on EGFR-TKI treatment response and survival. EGFR protein expression in lung cancer tissue was measured by immunohistochemistry with a specific antibody that recognizes the intracellular domain (ID) of EGFR. PTEN expression in lung cancer tissue was also evaluated with immunohistochemistry. PI3KCA gene amplification was detected by quantitative real-time polymerase chain reaction, and FGFR1 amplification was assessed by fluorescent in situ hybridization.

Results

EGFR ID expression (hazard ratio [HR] 0.53, P=0.022) and Eastern Cooperative Oncology Group (ECOG) performance status (PS) (HR 0.43, P=0.022) were significantly related with progression-free survival following EGFR-TKIs treatment. PTEN expression (HR 0.52, P=0.025) was significantly related to overall survival. The group of EGFR-positive or PTEN-positive patients with ECOG PS of 0 or 1 had better clinical outcomes than patients who were EGFR-negative and PTEN-negative or who had poor ECOG PS with longer median progression-free survival (2.1 vs 1.0 months, P=0.05) and overall survival (6.2 vs 2.1 months, P=0.05).

Conclusion

EGFR expression using an ID-specific antibody and PTEN protein expression may be used to identify SCCL patients who might benefit from EGFR-TKI treatment.

Estrogen receptor alpha gene amplification in breast cancer: 25 years of debate

Twenty-five years ago, Nembrot and colleagues reported amplification of the estrogen receptor alpha gene (ESR1) in breast cancer, initiating a broad and still ongoing scientific debate on the prevalence and clinical significance of this genetic aberration, which affects one of the most important genes in breast cancer. Since then, a multitude of studies on this topic has been published, covering a wide range of divergent results and arguments. The reported prevalence of this alteration in breast cancer ranges from 0% to 75%, suggesting that ESR1 copy number analysis is hampered by technical and interpreter issues. To date, two major issues related to ESR1 amplification remain to be conclusively addressed: (1) The extent to which abundant amounts of messenger RNA can mimic amplification in standard fluorescence in situ hybridization assays in the analysis of strongly expressed genes like ESR1, and (2) the clinical relevance of ESR1 amplification: Such relevance is strongly disputed, with data showing predictive value for response as well as for resistance of the cancer to anti-estrogen therapies, or for subsequent development of cancers in the case of precursor lesions that display amplification of ESR1. This review provides a comprehensive summary of the various views on ESR1 amplification, and highlights explanations for the contradictions and conflicting data that could inform future ESR1 research.

An integrated genome-wide approach to discover deregulated microRNAs in non-small cell lung cancer: Clinical significance of miR-23b-3p deregulation

In spite of significant technical advances, genesis and progression of non-small cell lung cancer (NSCLC) remain poorly understood. We undertook an integrated genetic approach to discover novel microRNAs that were deregulated in NSCLCs. A total 119 primary NSCLCs with matched normal were analyzed for genome-wide copy number changes. We also tested a subset of matched samples by microRNA expression array, and integrated them to identify microRNAs positioned in allelic imbalance area. Our findings support that most of the identified deregulated microRNAs (miR-21, miR-23b, miR-31, miR-126, miR-150, and miR-205) were positioned in allelic imbalance areas. Among microRNAs tested in independent 114 NSCLCs, overexpression of miR-23b was revealed to be a significantly poor prognostic factor of recurrence free survival (HR = 2.40, P = 0.005, 95%CI: 1.32–4.29) and overall survival (HR = 2.35, P = 0.005, 95%CI: 1.30–4.19) in multivariable analysis. In addition, overexpression of miR-23b in H1838 cell line significantly increased cell proliferation, while inhibition of miR-23b in H1437 and H1944 cell lines significantly decreased cell doubling time. In summary, integration of genomic analysis and microRNA expression profiling could identify novel cancer-related microRNAs, and miR-23b could be a potential prognostic marker for early stage NSCLCs. Further biological studies of miR-23b are warranted for the potential development of targeted therapy.

Acquirement of DNA copy number variations in non-small cell lung cancer metastasis to the brain

Brain metastasis is a major complication of non-small cell lung cancer (NSCLC) and leads to most of the mortality of this disease. However, the biological mechanisms and molecular features in brain metastasis of NSCLC are poorly understood. In the present study, we compared whole-genome copy number variations (CNVs) between a primary lung adenocarcinoma and secondary metastatic brain lesion from the same patient using array comparative genomic hybridization (aCGH). The number of CNV regions was markedly higher in the secondary metastatic tumor than the primary tumor in the lung. In detail, the common CNVs in both tumors included gains of 7p22, 7p12-p11, 7q11, 7q22, 21q22, and 19q13; gains of 1p33-p34, 1q22, 5p13 and 14q11 whereas losses of 3p, 4q31, 5q, 11p15, Xp21-p22 and Xq21 were identified only in the secondary lesion. Gene Ontology enrichment analysis revealed that the genes with amplified copy numbers in both tumors were related to such processes as DNA replication and mismatch repair. Genes only amplified in the metastatic tumor were enriched in processes that include leukocyte migration and organ development, and genes with a lower copy number in the secondary tumor included the processes of proteolysis regulation, negative regulation of cell proliferation and cell adhesion. These findings provided new insight into the genomic mechanism of the spread of lung adenocarcinoma to the brain, and the candidate genes identified serve as novel indicators or putative targets in NSCLC brain metastasis.

Using the MCF10A/MCF10CA1a Breast Cancer Progression Cell Line Model to Investigate the Effect of Active, Mutant Forms of EGFR in Breast Cancer Development and Treatment Using Gefitinib

BACKGROUND

Basal-like and triple negative breast cancer (TNBC) share common molecular features, poor prognosis and a propensity for metastasis to the brain. Amplification of epidermal growth factor receptor (EGFR) occurs in ~50% of basal-like breast cancer, and mutations in the epidermal growth factor receptor (EGFR) have been reported in up to ~ 10% of Asian TNBC patients. In non-small cell lung cancer several different mutations in the EGFR tyrosine kinase domain confer sensitivity to receptor tyrosine kinase inhibitors, but the tumourigenic potential of EGFR mutations in breast cells and their potential for targeted therapy is unknown.

MATERIALS AND METHODS

Constructs containing wild type, G719S or E746-A750 deletion mutant forms of EGFR were transfected into the MCF10A breast cells and their tumorigenic derivative, MCF10CA1a. The effects of EGFR over-expression and mutation on proliferation, migration, invasion, response to gefitinib, and tumour formation in vivo was investigated. Copy number analysis and whole exome sequencing of the MCF10A and MCF10CA1a cell lines were also performed.

RESULTS

Mutant EGFR increased MCF10A and MCF10CA1a proliferation and MCF10A gefitinib sensitivity. The EGFR-E746-A750 deletion increased MCF10CA1a cell migration and invasion, and greatly increased MCF10CA1a xenograft tumour formation and growth. Compared to MCF10A cells, MCF10CA1a cells exhibited large regions of gain on chromosomes 3 and 9, deletion on chromosome 7, and mutations in many genes implicated in cancer.

CONCLUSIONS

Mutant EGFR enhances the oncogenic properties of MCF10A cell line, and increases sensitivity to gefitinib. Although the addition of EGFR E746-A750 renders the MCF10CA1a cells more tumourigenic in vivo it is not accompanied by increased gefitinib sensitivity, perhaps due to additional mutations, including the PIK3CA H1047R mutation, that the MCF10CA1a cell line has acquired. Screening TNBC/basal-like breast cancer for EGFR mutations may prove useful for directing therapy but, as in non-small cell lung cancer, accompanying mutations in PIK3CA may confer gefitinib resistance.

Predictive and Prognostic Biomarkers for Patients Treated with Anti-EGFR Agents in Lung Cancer: A Systemic Review and Meta-Analysis

BACKGROUND

Several studies have investigated predictive and prognostic biomarkers for patients treated with anti-epidermal growth factor receptor (EGFR) agents in lung cancer. However, the conclusion is controversial.

MATERIALS AND METHODS

A meta-analysis was conducted to evaluate the associations of mutant K-ras, PIK3CA and PTEN deficiency with the efficacy of anti-EGFR agents in lung cancer. The primary endpoint was objective response rate (ORR). The secondary endpoints were overall survival (OS) and progression-free survival (PFS).

RESULTS

A total of 61 studies were included in the final meta-analysis. The result showed that K-ras mutation was a good predictor for ORR (RR=0.42, 95%CI, 0.33-0.55, p=0.000) and an effective prognostic marker for OS (HR=1.37, 95%CI, 1.15-1.65, p=0.001) and PFS (HR=1.33, 95%CI, 1.05-1.69, p=0.019). However, PTEN deficiency or PIK3CA mutation did not show any significance predictive value for ORR (PTEN, RR=0.82, 95%CI, 0.56-1.19, p=0.286; PIK3CA, RR=1.08, 95%CI, 0.17-6.66, P=0.938). And PTEN deficiency or expression of PIK3CA did not show significance prognostic value for OS (PTEN, HR=0.88, 95%CI, 0.31-2.46,P=0.805; PIK3CA, HR=0.79, 95%CI: 0.23-2.68, P=0.706).

CONCLUSIONS

Our meta-analysis showed that K-ras mutation may be an effective predictor in lung cancer patients treated with anti-EGFR agents. Whereas, the predictive and prognostic value of PTEN deficiency and PIK3CA mutation need to be further investigated.

Amplification of Chromosome 1q Genes Encoding the Phosphoinositide Signalling Enzymes PI4KB, AKT3, PIP5K1A and PI3KC2B in Breast Cancer

Little is known about the possible oncogenic roles of genes encoding for the phosphatidylinositol 4-kinases, a family of enzymes that regulate an early step in phosphoinositide signalling. To address this issue, the mutational status of all four human phosphatidylinositol 4-kinases genes was analyzed across 852 breast cancer samples using the COSMIC data resource. Point mutations in the phosphatidylinositol 4-kinase genes were uncommon and appeared in less than 1% of the patient samples however, 62% of the tumours had increases in gene copy number for PI4KB which encodes the phosphatidylinositol 4-kinase IIIbeta isozyme. Extending this analysis to subsequent enzymes in the phosphoinositide signalling cascades revealed that the only PIP5K1A, PI3KC2B and AKT3 genes exhibited similar patterns of gene copy number variation. By comparison, gene copy number increases for established oncogenes such as EGFR and HER2/Neu were only evident in 20% of the samples. The PI4KB, PIP5K1A, PI3KC2B and AKT3 genes are related in that they all localize to chromosome 1q which is often structurally and numerically abnormal in breast cancer. These results demonstrate that a gene quartet encoding a potential phosphoinositide signalling pathway is amplified in a subset of breast cancers.

Correlation between the expression levels of miR-1 and PIK3CA in non-small-cell lung cancer and their relationship with clinical characteristics and prognosis

AIMS

To examine the relationship between the expression levels of miR-1 and PIK3CA in resected non-small-cell lung cancer (NSCLC) tissues and clinical characteristics and prognosis.

MATERIALS & METHODS

Levels of miR-1 and PIK3CA in cancerous and normal tissues obtained from 55 patients with NSCLC were measured by real-time PCR and western blot assays, and their associations with clinicopathological features were evaluated.

RESULTS

A total of 69.1% of the NSCLC tissue samples showed low miR-1 expression (p < 0.05) and 70.9% showed high PIK3CA expression (p < 0.05). Patients with low miR-1 expression and those with high PIK3CA expression had significantly higher incidences of lymph node metastases and postoperative recurrences within 1 year after surgery than those with moderate miR-1 expression and moderate PIK3CA expression (p < 0.05 for both).

CONCLUSION

Low expression of miR-1 and overexpression of PIK3CA in NSCLC tissues may be useful predictors of lymph node metastasis and postoperative recurrence in patients with NSCLC.

Role of erlotinib in the treatment of advanced non-small-cell lung cancer patients with EGFR wild-type tumors

SUMMARY EGF receptor (EGFR) tyrosine kinase inhibitors (TKIs) have changed the treatment paradigm of non-small-cell lung cancer (NSCLC). The observation of a rapid response to single-agent EGFR TKIs led to the discovery of EGFR-activating mutations, with subsequent studies showing superior progression-free survival in treatment-naive patients with EGFR mutation-positive NSCLC treated with EGFR TKIs versus platinum doublets. On the basis of these findings it has been suggested that the benefit associated with EGFR TKI therapy in unselected NSCLC patients is limited to the subset of patients with EGFR mutation-positive disease. However, studies with erlotinib, a reversible EGFR TKI, have shown that while the drug is associated with a relatively low response rate in patients with EGFR wild-type tumors there is evidence to suggest that it has a positive impact on survival. Evidence supporting the clinical benefit of erlotinib in patients with EGFR wild-type tumors is discussed in this review.

ESR1 amplification in breast cancer by optimized RNase FISH: frequent but low-level and heterogeneous

Prevalence of ESR1 amplification in breast cancer is highly disputed and discrepancies have been related to different technical protocols and different scoring approaches. In addition, pre-mRNA artifacts have been proposed to influence outcome of ESR1 FISH analysis. We analyzed ESR1 gene copy number status combining an improved RNase FISH protocol with multiplex ligation-dependent probe amplification (MLPA) after laser microdissection. FISH showed a high prevalence of ESR1 gains and amplifications despite RNase treatment but MLPA did not confirm ESR1 copy number increases detected by FISH in more than half of cases. We suggest that the combination of the ESR1-specific intra-tumor heterogeneity and low-level copy number increase accounts for these discrepancies.

Identification of uncommon PIK3CA mutations in lung cancer by using pyrosequencing

INTRODUCTION

Phospatidylinositol-3-kinases (PI3K) play an important role in various cell processes. Oncogenic mutations in the PIK3CA gene, which codes for the catalytic subunit, have been identified in various malignancies and activate the PI3K/AKT/mTOR pathway, which is a critical driver of tumorigenesis.

METHODS

We tested 41 tumor samples with known KRAS, BRAF, and EGFR mutation status for the occurrence of mutations in the PIK3CA gene, using a pyrosequencing assay.

RESULTS

Pyrosequencing revealed 2 mutations (4.9%) in the PIK3CA gene, one in exon 9 and the other in exon 20. Both mutations have not been identified yet in lung tumor tissue.

DISCUSSION

The screening of our small patient cohort by pyrosequencing identified 2 mutations (4.9%) in PIK3CA, one in exon 9 (Q546H) and the other in exon 20 (M1043T). Both mutations have not been described in lung tumors yet and seem to be rather uncommon mutations. Future screening of large patient cohorts with pyrosequencing may contribute to the detection of more mutations in lung cancer because of the low limit of detections of this method and may contribute to a better understanding of the interaction of mutations and tumorigenesis.

Loss of phosphatase and tensin homolog protein expression is an independent poor prognostic marker in lung adenocarcinoma

INTRODUCTION

Phosphatase and tensin homolog (PTEN) has been established as a tumor suppressor gene with an important role in regulating the phosphatidylinositol-3-kinase/AKT antiapoptotic and survival pathway. The prognostic role of PTEN in non-small-cell lung carcinoma has not been evaluated completely in the context of other molecular information.

METHODS

Tissue microarrays containing 152 resected non-small-cell lung cancer specimens were used to investigate PTEN and p53 by immunohistochemistry and PTEN by fluorescence in situ hybridization. DNA was isolated and subjected to mutational profiling using the Sequenom Oncocarta v1.0 panel. Clinicopathological features were correlated with PTEN expression, gene copy number, and mutation status.

RESULTS

PTEN staining was absent in 63 (41.4%) of the cases. Significantly more squamous cell carcinomas compared with adenocarcinomas demonstrated loss of (negative) PTEN staining (26 of 44 [59%] versus 32 of 94 [34%]; p = 0.009). PTEN gene copy deletion was present in only seven of 124 evaluable cases (5.6%); all deleted cases were immunohistochemistry negative. In univariate and multivariate (MV) analyses adjusted for sex, age, histology, and stage, loss of PTEN protein expression was associated with significantly shorter disease-free survival (MV hazard ratio: 1.78, 95% confidence interval: 1.01-3.14, p = 0.048), whereas no significant associations were seen with p53 or KRAS and epidermal growth factor receptor (EGFR) mutation status. Importantly, the prognostic value of absent PTEN staining was limited to adenocarcinomas, with MV disease-free survival hazard ratio of 2.68 (95% confidence interval: 1.35-5.32, p = 0.005), whereas no such association was seen in squamous cell carcinomas.

CONCLUSION

Absence of PTEN protein expression is an independent prognostic marker in early-stage resected lung adenocarcinoma.