Transcripts in pretreatment biopsies from a three-arm randomized trial in metastatic non-small-cell lung cancer

STNM1 in human cancers: role, function and potential therapy sensitizer

STMN1 belongs to the stathmin gene family, it encodes a cytoplasmic phosphorylated protein, stathmin1, which is commonly observed in vertebrate cells. STMN1 is a structural microtubule-associated protein (MAP) that binds to microtubule protein dimers rather than microtubules, with each STMN1 binding two microtubule protein dimers and preventing their aggregation, leading to microtubule instability. STMN1 expression is elevated in a number of malignancies, and inhibition of its expression can interfere with tumor cell division. Its expression can change the division of tumor cells, thereby arresting cell growth in the G2/M phase. Moreover, STMN1 expression affects tumor cell sensitivity to anti-microtubule drug analogs, including vincristine and paclitaxel. The research on MAPs is limited, and new insights on the mechanism of STMN1 in different cancers are emerging. The effective application of STMN1 in cancer prognosis and treatment requires further understanding of this protein. Here, we summarize the general characteristics of STMN1 and outline how STMN1 plays a role in cancer development, targeting multiple signaling networks and acting as a downstream target for multiple microRNAs, circRNAs, and lincRNAs. We also summarize recent findings on the function role of STMN1 in tumor resistance and as a therapeutic target for cancer.

Diagnostic, Predictive, and Prognostic Biomarkers in Non-Small Cell Lung Cancer (NSCLC) Management

Lung cancer is the leading cause of cancer-related deaths worldwide. Despite growing efforts for its early detection by screening populations at risk, the majority of lung cancer patients are still diagnosed in an advanced stage. The management of lung cancer has dramatically improved in the last decade and is no longer based on the "one-fits-all" paradigm or the general histological classification of non-small cell versus small cell lung cancer. Emerging options of targeted therapies and immunotherapies have shifted the management of lung cancer to a more personalized treatment approach, significantly influencing the clinical course and outcome of the disease. Molecular biomarkers have emerged as valuable tools in the prognosis and prediction of therapy response. In this review, we discuss the relevant biomarkers used in the clinical management of lung tumors, from diagnosis to prognosis. We also discuss promising new biomarkers, focusing on non-small cell lung cancer as the most abundant type of lung cancer.

Novel pyrazolo[4,3-d]pyrimidine microtubule targeting agents (MTAs): Synthesis, structure-activity relationship, in vitro and in vivo evaluation as antitumor agents

The design, synthesis, and biological evaluation of a series novel N1‑methyl pyrazolo[4,3-d]pyrimidines as inhibitors of tubulin polymerization and colchicine binding were described here. Synthesis of target compounds involved alkylation of the pyrazolo scaffold, which afforded two regioisomers. These were separated, characterized and identified with 1H NMR and NOESY spectroscopy. All compounds, except 10, inhibited [3H]colchicine binding to tubulin, and the potent inhibition was similar to that obtained with CA-4. Compounds 9 and 11-13 strongly inhibited the polymerization of tubulin, with IC50 values of 0.45, 0.42, 0.49 and 0.42 μM, respectively. Compounds 14-16 inhibited the polymerization of tubulin with IC50s near ∼1 μM. Compounds 9, 12, 13 and 16 inhibited MCF-7 breast cancer cell lines and circumvented βIII-tubulin mediated cancer cell resistance to taxanes and other MTAs, and compounds 9-17 circumvented Pgp-mediated drug resistance. In the standard NCI testing protocol, compound 9 exhibited excellent potency with low to sub nanomolar GI50 values (≤10 nM) against most tumor cell lines, including several multidrug resistant phenotypes. Compound 9 was significantly (P < 0.0001) better than paclitaxel at reducing MCF-7 TUBB3 (βIII-tubulin overexpressing) tumors in a mouse xenograft model. Collectively, these studies support the further preclinical development of the pyrazolo[4,3-d]pyrimidine scaffold as a new generation of tubulin inhibitors and 9 as an anticancer agent with advantages over paclitaxel.

RRM1 expression and the clinicopathological characteristics of patients with non-small cell lung cancer treated with gemcitabine

Background

The usefulness of ribonucleotide reductase catalytic subunit M1 (RRM1) for predicting the therapeutic effects of gemcitabine-containing chemotherapy in patients with non-small cell lung cancer (NSCLC) remains controversial. RRM1-positive patients show unique clinicopathological features.

Methods

Here, we performed a meta-analysis to systematically evaluate the relationship between RRM1 expression and the clinicopathological characteristics of NSCLC patients treated with gemcitabine-containing regimens. A comprehensive electronic and manual search was performed to identify relevant articles. The pooled relative risk (RR) and 95% CI were used to estimate the relation between the clinicopathological characteristics of NSCLC patients and RRM1 expression.

Results

The study included 31 observational studies and 3,667 patients. The analysis showed no significant association between RRM1 expression and pathological type, stage, and smoking status; however, RRM1 positivity was significantly lower in women than in men (43.0% vs 51.7%, RR=0.84, 95% CI: 0.74-0.94, P=0.004).

Conclusion

The present pooled analyses demonstrated that RRM1 positivity in women with advanced NSCLC was associated with a higher rate of response to gemcitabine-containing regimens. Immunohistochemistry may be valuable to prescreen for RRM1 expression in clinical practice, whereas PCR can be routinely used as a verification method. These findings will help design suitable molecular-targeted therapies for NSCLC.

MicroRNA-200 families and prognostic value in various carcinomas: A systematic review and meta-analysis

BACKGROUND

Recently, some studies have showed that miR-200 families act as novel biomarkers for the prediction of cancer outcomes.

AIMS

This meta-analysis was designed to investigate the associations between miR-200 families and the prognosis of patients with various cancers.

MATERIALS & METHODS

Eligible published databases including PubMed, Embase and Chinese National Knowledge Infrastructure (CNKI) databases were searched for articles until October 18, 2016. We performed a meta-analysis by calculating pooled hazard ratios (HR) and 95% confidence intervals (CI). Data were extracted from studies comparing overall survival (OS), progression-free survival (PFS) or recurrence-free survival (RFS).

RESULTS

For OS, the pooled HR was 1.54 (95% CI: 1.01-2.33), showing that high miR-200 family was clearly related to poor survival in various carcinomas, but no significantly association was found in PFS or RFS. Subgroup analysis indicated that upregulated miR-200 family was linked to poor OS in Asians (HR = 2.19, 95% CI: 1.27-3.78) but not in Caucasians (HR = 0.94, 95% CI: 0.46-1.91). Similarly, high miR-200 expression could not clearly predict the relationship with PFS and RFS. For cancer type, high miR-200 also predicted poor OS among lung cancer patients (HR = 3.09, 95% CI: 1.75-5.46). Besides, only elevated miR-200c of the miR-200 family indicated a significantly poor OS (HR = 2.25, 95% CI: 1.39-3.64).

DISCUSSION

Aberrant expression of miRNAs played a crucial role in the area of human carcinomas. Many studies have indicated that miRNAs are considered promising tumor biomarkers for prognosis and potential targets for clinical treatment. We have testified that high levels of miR-200 family expression (predominantly miR-200c) are significantly associated with poor survival and prognostic outcomes of patients with cancers, especially in lung cancer. However, no statistically significant results were calculated for miR-200a/b and miR-429, and this might result from a relatively small number of articles about them. In other tumor models except lung cancer, our results indicated that high miR-200 family was not obviously associated with OS (Gastric or Colorectal cancer; Ovarian cancer; Others). In addition, some other records showed the opposite results, for they exhibited that upregulated miR-200 family level was linked to longer survival. For ethnic group, our stratified analyses showed that the Asian population predicted poor OS. While the Caucasian population did not exhibit an significant association with OS. This discrepancy might result from different hereditary backgrounds and environment exposure. Although these results have indicated that miR-200 families were promising biomarkers to predict prognosis for patients with cancers, there were several limitations in this analysis that would impact its quality. Generally, further studies should be warranted to clarify this question and to provide a new novel idea for routine clinical application.

CONCLUSION

Our findings suggest that miR-200 family might be a potentially useful biomarker for predicting cancer prognosis, especially for lung cancer in Asians.

Association of BRCA1, ERCC1, RAP80, PKM2, RRM1, RRM2, TS, TSP1, and TXR1 mRNA expression levels between primary tumors and infiltrated regional lymph nodes in patients with resectable non-small cell lung cancer

Differences in gene expression levels between the primary tumors (PTs) and matched regional lymph nodal metastases (LNs) in patients with totally excised non-small cell lung cancer (NSCLC) were explored. Microdissected formalin-fixed paraffin-embedded (FFPE) samples from (PT) and their matched infiltrated LNs, from 239 patients [183 (with matched PT and LNs samples)-case and 56 PT only samples-control cohorts] were analyzed for BRCA1, ERCC1, RAP80, PKM2, RRM1, RRM2, TS, TSP1, and TXR1 mRNA expression by quantitative real-time polymerase-chain reaction (PCR). Moderately positive correlation between the expression of each gene in the PT and the matched LNs was observed. Concordance rates between the PT and the LNs were: BRCA1 (67.7%), ERCC1 (68.4%), PKM2 (63.4%), RAP80 (68.8%), RRM1 (70.9%), RRM2 (69%), TS (72.9%), TSP1 (69.8%), TXR1 (63.7%). Expression levels and their differences were correlated with Relapse-Free Survival (RFS) and Overall Survival (OS). High BRCA1 PT in patients with squamous histology was associated with increased OS (p = 0.036). High TSP1 PT levels were shown to be the only independent prognostic factor for OS and RFS (p = 0.023 and p = 0.007). PKM2 low levels in both PT and matched LNs were associated with better OS irrespective of the underlying histology (p = 0.031). RRM1 discordant levels between PT and matched LNs were associated with worse OS in squamous tumors (p = 0.019) compared to patients with both low expression in PT and LN.TXR1 high levels in both PT and matched LNs were associated with better OS in patients with squamous tumors (p = 0.007).These findings indicate that there is different gene expression between PT and matched LNs which may affect the outcome in early NSCLC and therefore PT's molecular biology should not be the sole determinant for prognostication.

5'-nucleotidase cN-II emerges as a new predictive biomarker of response to gemcitabine/platinum combination chemotherapy in non-small cell lung cancer

A number of pharmacogenetic studies have been carried out in non-small-cell lung cancer (NSCLC) to identify and characterize genes involved in chemotherapy activity. However, the results obtained so far are controversial and no reliable biomarker is currently used to predict clinical benefit from platinum-based chemotherapy, which represents the cornerstone of treatment of advanced NSCLC. This study investigated the expression levels of ERCC1 and of six genes (RRM1, RRM2, hENT1, dCK, cN-II and CDA) involved in gemcitabine metabolism in locally/advanced NSCLC patients treated with gemcitabine/platinum combination. Gene expression was assessed by quantitative-PCR in laser-microdissected specimens and correlated with tumor response. Frequency distribution of responses above and below the median expression level of biomarkers was compared using a two-sided Fisher’s test. 5′-nucleotidase (cN-II) was the only gene differently expressed (p = 0.016) in the responders (complete/partial-response) compared to non-responders (stable/progressive disease). In the multivariate analysis, overexpression of this catabolic enzyme of gemcitabine remained a significant negative predictive factor. Patients with low cN-II had a modest trend toward increased survival, while both survival and progression-free survival were significantly longer in a more homogenous validation cohort of 40 advanced NSCLC (8.0 vs. 5.1 months, p = 0.026). Moreover, in vitro studies showed that silencing or pharmacological inhibition of cN-II increased the cytotoxicity of gemcitabine. This is the first study demonstrating the role of cN-II as a predictor of response to gemcitabine/platinum combinations in NSCLC. Its validation in prospective studies may improve clinical outcome of selected patients.

The miR-200 family in ovarian cancer

Ovarian cancer (OC) is the most lethal gynecological malignancy. Its insidious nature, manifesting with little to no symptoms until the disease progresses to metastasis, along with a wide diversity of histological subtypes and corresponding clinical behavior, poses significant therapeutic challenges. The genetic profiling of this aggressive tumor and its subtypes has led to the identification of various molecular markers of prognosis. Among these, the miR-200 family of miRNAs appears to play an important role. The deregulated expression of the miR-200 family members has been detected in a variety of OC studies. The present review examines the potential usefulness of the miR-200 family members as prognostic indicators in ovarian cancer and their impact across different OC publications, with a particular focus on prognostic features, such as disease stage, tumor histology, survival and response to chemotherapy. We present the potential usefulness of the miR-200 family genes as prognostic indicators in OC and highlight the tendency that miR-200 overexpression corresponds with an advanced cancer stage.

High stathmin expression is a marker for poor clinical outcome in endometrial cancer: An NRG oncology group/gynecologic oncology group study

OBJECTIVE

Gynecologic Oncology Group (GOG) 177 demonstrated that addition of paclitaxel to a backbone of adriamycin/cisplatin improves overall survival (OS) and progression-free survival (PFS) for patients with advanced or recurrent endometrial cancer. Using patient specimens from GOG-177, our objective was to identify potential mechanisms underlying the improved clinical response to taxanes. Stathmin (STMN1) is a recognized poor prognostic marker in endometrial cancer that functions as a microtubule depolymerizing protein, allowing cells to transit rapidly through mitosis. Therefore, we hypothesized that one possible mechanism underlying the beneficial effects of paclitaxel could be to counter the impact of stathmin.

METHODS

We analyzed the expression of stathmin by immunohistochemistry (IHC) in 69 specimens from patients enrolled on GOG-177. We also determined the correlation between stathmin mRNA expression and clinical outcomes in The Cancer Genome Atlas (TCGA) dataset for endometrial cancer.

RESULTS

We first established that stathmin expression was significantly associated with shorter PFS and OS for all analyzed cases in both GOG-177 and TCGA. However, subgroup analysis from GOG-177 revealed that high stathmin correlated with poor PFS and OS particularly in patients who received adriamycin/cisplatin only. In contrast, there was no statistically significant association between stathmin expression and OS or PFS in patients treated with paclitaxel/adriamycin/cisplatin.

CONCLUSIONS

Our findings demonstrate that high stathmin expression is a poor prognostic marker in endometrial cancer. Paclitaxel may help to negate the impact of stathmin overexpression when treating high risk endometrial cancer cases.

Prognostic impact of stathmin 1 expression in patients with lung adenocarcinoma

OBJECTIVE

Stathmin 1 is a major cytosolic phosphoprotein that regulates microtubule dynamics and is associated with malignant phenotypes in various cancers, including non-small cell lung cancer. We aimed to determine differences in overall survival and disease-free proportion in patients with lung adenocarcinoma stratified by stathmin 1 tumor expression.

METHODS

With the use of immunohistochemistry, stathmin 1 expression was determined in resection specimens from 303 patients with adenocarcinoma. Associations between stathmin 1 protein expression and overall and disease-free proportion were assessed (Kaplan-Meier survival curves compared with log-rank statistics). Cox proportional hazards regression determined the hazard for death stratified by stathmin 1, adjusting for clinicopathologic characteristics.

RESULTS

During follow-up, 74 (24.4%) recurrences and 73 (24.1%) all-cause deaths were recorded. Expressed in 53.8% of adenocarcinoma cases, overall survival and disease-free proportion were significantly worse in stathmin 1-positive patients (log-rank P < .001 and P < .001, respectively). When adjusted for clinical and pathologic factors, stathmin 1 expression was an independent prognostic variable for both overall survival (hazard ratio, 2.21; 95% confidence interval, 1.28-3.80) and disease-free proportion (hazard ratio, 2.02; 95% confidence interval, 1.13-3.63) and for disease-free proportion even in the subset of patients with stage I (hazard ratio, 2.79; 95% confidence interval, 1.07-7.27). There was no significant difference between the stathmin 1-positive patients with stage IA and patients with stage IB in overall survival (P = .975) and disease-free proportion (P = .490), respectively.

CONCLUSIONS

Stathmin 1 expression was an independent prognostic factor for adenocarcinoma, even when restricted to patients with early-stage cancer.

Correlation of DNA Repair Gene Polymorphisms With Clinical Outcome in Patients With Locally Advanced Non-Small-Cell Lung Cancer Receiving Induction Chemotherapy Followed by Surgery

OBJECTIVE

The aim of this study was to evaluate whether xeroderma pigmentosum group D (XPD) and ribonucleotide reductase subunit M1 (RRM1) polymorphisms influenced clinical outcome in patients with stage IIIA-B non-small-cell lung cancer (NSCLC) treated with neoadjuvant gemcitabine/cisplatin/docetaxel followed by surgery.

MATERIALS AND METHODS

A total of 109 patients with stage IIIA and IIIB NSCLC were prospectively genotyped to examine a potential association between XPD 312 (aspartic acid [Asp]/asparagine [Asn]), XPD 751 (lysine [Lys]/glutamine [Gln]), and RRM1 (-37 C/A) polymorphisms with response and survival.

RESULTS

The median survival was 32.14 months for carriers of XPD 312 Asp/Asp and 12.04 months for those with the variant Asn allele (P = .05). In addition, event-free survival was longer for patients with the XPD 312 Asp/Asp genotype compared with patients with Asp/Asn or Asn/Asn (P = .03). A similar but nonsignificant trend was observed for the XPD 751 genotype. In a multivariate analysis, complete resection and age emerged as prognostic factors for overall survival; in patients with incomplete resection or exploratory thoracotomy, XPD 312 was the most significant prognostic factor (P = .03).

CONCLUSION

The XPD 312 single nucleotide polymorphism is a prognostic factor for survival in patients with locally advanced NSCLC receiving induction chemotherapy followed by surgery. The Asn allele is associated with unfavorable outcome and could be used for better stratification of patients.

Predictors of chemotherapy efficacy in non-small-cell lung cancer: a challenging landscape

BACKGROUND

Conventional cytotoxic chemotherapy (CCC) is the backbone of non-small-cell lung cancer (NSCLC) treatment since decades and still represents a key element of the therapeutic armamentarium. Contrary to molecularly targeted therapies and immune therapies, for which predictive biomarkers of activity have been actively looked for and developed in parallel to the drug development process ('companion biomarkers'), no patient selection biomarker is currently available for CCC, precluding customizing treatment.

MATERIALS AND METHODS

We reviewed preclinical and clinical studies that assessed potential predictive biomarkers of CCC used in NSCLC (platinum, antimetabolites, topoisomerase inhibitors, and spindle poisons). Biomarker evaluation method, analytical validity, and robustness are described and challenged for each biomarker.

RESULTS

The best-validated predictive biomarkers for efficacy are currently ERCC1, RRM1, and TS for platinum agents, gemcitabine and pemetrexed, respectively. Other potential biomarkers include hENT1 for gemcitabine, class III β-tubulin for spindle poisons, TOP2A expression and CEP17 duplication (mostly studied for predicting anthracyclines efficacy) whose applicability concerning etoposide would deserve further evaluation. However, none of these biomarkers has till now been validated prospectively in an appropriately designed and powered randomised trial, and none of them is currently ready for implementation in routine clinical practice.

CONCLUSION

The search for predictive biomarkers to CCC has been proven challenging. If a plethora of biomarkers have been evaluated either in the preclinical or in the clinical setting, none of them is ready for clinical implementation yet. Considering that most mechanisms of resistance or sensitivity to CCC are multifactorial, a combinatorial approach might be relevant and further efforts are required.

Design, Synthesis, and Preclinical Evaluation of 4-Substituted-5-methyl-furo[2,3-d]pyrimidines as Microtubule Targeting Agents That Are Effective against Multidrug Resistant Cancer Cells

The design, synthesis, and biological evaluations of eight 4-substituted 5-methyl-furo[2,3-d]pyrimidines are reported. Synthesis involved N(4)-alkylation of N-aryl-5-methylfuro[2,3-d]pyrimidin-4-amines, obtained from Ullmann coupling of 4-amino-5-methylfuro[2,3-d]pyrimidine and appropriate aryl iodides. Compounds 3, 4, and 9 showed potent microtubule depolymerizing activities, while compounds 6-8 had slightly lower potency. Compounds 4, 6, 7, and 9 inhibited tubulin assembly with IC50 values comparable to that of combretastatin A-4 (CA-4). Compounds 3, 4, and 6-9 circumvented Pgp and βIII-tubulin mediated drug resistance, mechanisms that can limit the efficacy of paclitaxel, docetaxel, and the vinca alkaloids. In the NCI 60-cell line panel, compound 3 exhibited GI50 values less than 10 nM in 47 of the cell lines. In an MDA-MB-435 xenograft model, compound 3 had statistically significant antitumor effects. The biological effects of 3 identify it as a novel, potent microtubule depolymerizing agent with antitumor activity.

Taxanes in the treatment of non-small cell lung cancer

Paclitaxel and docetaxel, drugs that bind tightly to beta-tubulin and disrupt microtubule dynamics, are widely used in the treatment of non-small cell lung cancer (NSCLC), the most common cause of cancer death in men and women living in the US. These well tolerated drugs, alone or in combination with another cytotoxic agent, have been shown to increase the survival of patients with metastatic disease or malignant effusions. Both paclitaxel and docetaxel can be combined with concurrent chest irradiation for patients with locally advanced NSCLC. The combination of carboplatin and paclitaxel, when given postoperatively to patients with stage IB NSCLC, improved survival compared with surgery alone, with little toxicity. Taxane combinations are undergoing study as adjuvant therapy for patients with other stages of operable disease. Except for a recent trial with bevacizumab, efforts to improve the efficacy of taxane/platinum combinations in patients with advanced disease by adding a third 'targeted' drug have thus far been unsuccessful.

Chemotherapy Resistance in Lung Cancer

Despite a growing interest in development of non-cytotoxic targeted agents, systemic chemotherapy is still the mainstay of treatment for both non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC). However, chemotherapy resistance limits our ability to effectively treat advanced lung cancer. Some lung tumors are intrinsically resistant to chemotherapy, and in virtually all cases, even the initial responders rapidly develop acquired resistance. While targeting histology could result in enhanced tumor sensitivity to a particular chemotherapeutic agent, better understanding of molecular determinants of chemotherapy sensitivity/resistance would be critically important. Development of predictive biomarkers to personalize chemotherapeutic agents and combining novel agents targeting specific resistance pathways with standard chemotherapy could be some promising strategies to overcome chemotherapy resistance in lung cancer. In this chapter, we will discuss some key mechanisms of resistance for commonly used chemotherapeutic agents in lung cancer.

Potent effect of adenoviral vector expressing short hairpin RNA targeting ribonucleotide reductase large subunit M1 on cell viability and chemotherapeutic sensitivity to gemcitabine in non-small cell lung cancer cells

BACKGROUND

Ribonucleotide reductase large subunit (RRM1) is the main enzyme responsible for synthesis of the deoxyribonucleotides used during DNA synthesis. It is also a cellular target for gemcitabine (GEM). Overexpression of RRM1 is reportedly associated with resistance to GEM and the poor prognosis for many types of malignant tumours. Aim of the present study is to establish gene therapy against RRM1-overexpressing tumours.

METHOD

An adenoviral vector that encoded a short hairpin siRNA targeting the RRM1 gene (Ad-shRRM1) was constructed. Two RRM1-overexpressing non-small cell lung cancer (NSCLC) lines, MAC10 and RERF-LC-MA, were used. Finally, a human tumour xenograft model in nude mice was prepared by subcutaneously implanting tumours derived from RERF-LC-MA cells.

RESULTS

Ad-shRRM1 effectively downregulated RRM1 mRNA and protein in both types of NSCLC cells and significantly reduced the percentage of viable cells as detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay (p<0.005). Caspase 3/7 analysis revealed that transfection with Ad-RRM1 increased the percentage of apoptotic cells in culture containing either type of RRM1-overexpressing cell (p<0.001). Treatment with Ad-shRRM1 exerted a potent antitumour effect against the RRM1-overexpressing RERF-LC-MA xenografts (p<0.05). Furthermore, Ad-shRRM1-mediated inhibition of RRM1 specifically increased sensitivity to gemcitabine of each type of RRM1-overexpressing tumour cell. Combination treatment with Ad-shRRM1 and GEM exerted significantly greater inhibition on cell proliferation than Ad-shRRM1 or GEM treatment alone.

CONCLUSION

RRM1 appeared to be a promising target for gene therapy, and Ad-shRRM1 had strong antitumour effects, specifically anti-proliferative and pro-apoptotic effects, against NSCLC cells that overexpressed RRM1. Combination therapy with Ad-shRRM1 and GEM may become a new treatment option for patients with NSCLC.

Predictive value of STMN1 gene promoter polymorphism (-2166T>C) in patients with advanced NSCLC treated with the combination of platinum compounds and vinorelbine

Purpose

The combination of platinum compounds and vinorelbine is often used as a first-line treatment in patients with locally advanced or metastatic non-small cell lung cancer (NSCLC), without activating EGFR mutations and ALK rearrangement. Unfortunately, less than half of the patients benefit from chemotherapy. Moreover, majority of patients are exposed to a number of side effects of chemotherapy. Stathmin-1 (STMN1, oncoprotein 18) affects significantly microtubule dynamics and formation of the mitotic spindle. Therefore, the change in the STMN1 gene may be a potential predictive factor of response to treatment regimens containing a cytostatics-disrupting microtubule dynamics (vinca alkaloids and taxoids). The aim of the study was to determine the relationship between a single nucleotide polymorphism (SNP) of the promoter of STMN1 gene −2166T>C) and the effectiveness of chemotherapy based on platinum compounds and vinorelbine in patients with NSCLC.

Methods

The investigated population consisted of 110 locally advanced or metastatic NSCLC patients treated with first-line chemotherapy, based on platinum compounds and vinorelbine. SNP was determined by SNaPshot™ PCR in DNA isolated from peripheral blood leukocytes.

Results

The median progression-free survival (PFS) was significantly shorter in carriers of TT genotype of the STMN1 gene compared with patients with CC or CT genotypes (2.75 vs. 6.5 months; p = 0.0033; HR 5.91, 95 % CI 1.81–19.33). Evaluated SNP did not significantly affect the response to treatment and the overall survival of the patients.

Conclusion

Rare TT genotype of STMN1 gene may be an unfavorable predictive factor of chemotherapy based on platinum compounds and vinorelbine, in patients with NSCLC.

Effects of JWA, XRCC1 and BRCA1 mRNA expression on molecular staging for personalized therapy in patients with advanced esophageal squamous cell carcinoma

BACKGROUND

DNA damage repair genes JWA, XRCC1 and BRCA1 were associated with clinical outcomes and could convert the response to the cisplatin-based therapy in some carcinomas. The synergistic effects of JWA, XRCC1 and BRCA1 mRNA expression on personalized therapy remain unknown in advanced esophageal squamous cell carcinoma (ESCC).

METHODS

We employed quantitative real-time polymerase chain reaction (qPCR) to determine the expression of JWA, XRCC1 and BRCA1 mRNA in paraffin-embedded specimen from 172 patients with advanced ESCC who underwent the first-line cisplatin-or docetaxel-based treatments.

RESULTS

High JWA or XRCC1mRNA expression was correlated with longer median overall survival (mOS) in all the patients (both P<0.001) or in subgroups with different regimens (all P<0.05), but not correlated with response rate (RR, all P>0.05). Multivariate analysis revealed that high JWA (HR 0.22; 95% CI 0.13-0.37; P<0.001) or XRCC1 (HR 0.36; 95% CI 0.21-0.63; P<0.001) mRNA expression emerged as the independent prognostic factors for ESCC patients in this cohort. But no significant difference in prognostic efficacy was found between JWA plus XRCC1 and JWA alone through ROC analysis. Further subgroup analysis showed cisplatin-based treatments could improve mOS of patients with low JWA expression (P<0.05), especially in those with low BRCA1 expression simultaneously (P<0.001); while in patients with high JWA expression, high BRCA1 mRNA expression was correlated with increased mOS in docetaxel-based treatments (P=0.044).

CONCLUSION

JWA, XRCC1and BRCA1 mRNA expression could be used as predictive markers in molecular staging for personalized therapy in patients with advanced ESCC who received first-line cisplatin- or docetaxel-based treatments.

[Down-regulated βIII-tubulin expression can reverse paclitaxel resistance in A549/taxol cells lines]

BACKGROUND

Chemotherapy drug resistance is the primary causes of death in patients with pulmonary carcinoma which make tumor recurrence or metastasis. β-tubulin is the main cell targets of anti-microtubule drug. Increased expression of βIII-tubulin has been implicated in non-small cell lung cancer (NSCLC) cell lines. To explore the relationship among the expression level of βIII-tubulin and the sensitivity of A549/Taxolcell lines to Taxol and cell cycles and cell apoptosis by RNA interference-mediated inhibition of βIII-tubulin in A549/Taxol cells.

METHODS

Three pairs of siRNA targetd βIII-tubulin were designed and prepared, which were transfected into A549/Taxol cells using LipofectamineTM 2000. We detected the expression of βIII-tubulin mRNA using Real-time fluorescence qRT-PCR. Tedhen we selected the most efficient siRNA by the expression of βIII-tubulin mRNA in transfected group. βIII-tubulin protein level were mesured by Western blot. The taxol sensitivity in transfected group were evaluated by MTT assay. And the cell apoptosis and cell cycles were determined by flow cytometry.

RESULTS

βIII-tubulin mRNA levels in A549/Taxol cells were significantly decreased in transfected grop by Real-time qRT-PCR than control groups. And βIII-tubulin siRNA-1 sequence showed the highest transfection efficiency, which was (87.73±4.87)% (P<0.01); Western blot results showed that the expressional level of BIII tublin protein was significantly down-reulated in the transfectant cells than thant in the control cells. By MTT assay, we showed that the inhibition ratio of Taxol to A549/Taxol cells transfeced was higher than that of control group (51.77±4.60)% (P<0.01). The early apoptosis rate of A549/Taxol cells in transfected group were significantly higher than that of control group (P<0.01); G2-M content in taxol group obviously increased than untreated samples by the cell cycle (P<0.05).

CONCLUSIONS

βIII-tubulin down-regulated significantly sensitized NSCLC A549/Taxol cells to Paclitaxel.

Use of TUBB3 for patient stratification and prognosis in lung cancer

SUMMARY 

Microtubules play a crucial role in the eukaryote replicative cell machinery and antimicrotubule drugs such as vinca alkaloids and taxanes are important drugs in the treatment of several solid tumors. TUBB3 has in retrospective studies shown to be of significance with regard to outcome in NSCLC patients treated with anti-microtubule drugs. However, it is still controversial whether or not TUBB3 has a prognostic or a predictive value. This review provides an overview of preclinical and clinical studies that have presented data on the role of TUBB3 in NSCLC.

Are we ready to use biomarkers for staging, prognosis and treatment selection in early-stage non-small-cell lung cancer?

Lung cancer accounts for the majority of cancer-related deaths worldwide. At present, platinum-based therapy represents the standard of care in fit stage II and IIIA non-small cell lung cancer (NSCLC) patients following surgical resection. In advanced disease, personalized chemotherapy and targeted biologic therapy based on histological and molecular tumor profiling have already shown promise in terms of optimizing treatment efficacy. While disease stage is associated with outcome and is commonly used to determine adjuvant treatment eligibility, it is known that a subset of patients with early stage disease experience shorter survival than others with the same clinicopathological characteristics. Improved methods for identifying these individuals, at or near the time of initial diagnosis, may inform the decision to pursue adjuvant therapy options. Among the numerous candidate molecular biomarkers, only few gene-expression profiling signatures provide clinically relevant information, while real-time quantitative polymerase-chain reaction (RT-qPCR) strategy involving relatively small numbers of genes offers a practical alternative with high cross-platform performance. mRNA and/or protein expression levels of excision repair cross-complementation group 1 (ERCC1), ribonucleotide reductase M subunit 1 (RRM1) and breast cancer susceptibility gene 1 (BRCA1) are among the most promising potential biomarkers for early disease and their clinical utility is currently being evaluated in randomized phase II and III clinical trials. This review describes the most promising clinicopathological and molecular biomarkers with predictive and prognostic significance in lung cancer that have been identified through advanced research and which could influence adjuvant and neoadjuvant chemotherapy decisions for operable NSCLC in routine clinical practice.

Predictive models for customizing chemotherapy in advanced non-small cell lung cancer (NSCLC)

The backbone of first-line treatment for Epidermal Growth Factor (EGFR) wild-type (wt) advanced Non-small cell lung cancer (NSCLC) patients is the use of a platinum-based chemotherapy combination. The treatment is characterized by great inter-individual variability in outcome. Molecular predictive markers are extremely needed in order to identify patients most likely to benefit from platinum-based treatment and resistant ones, thus optimizing chemotherapy approach in NSCLC. Several components of DNA repair response (DRR) have been investigated as potential predictive markers. Among them, high levels of expression of ERCC1, both at protein and mRNA levels, have been associated with resistance to cisplatin in NSCLC. In addition, low levels of expression of RRM1, a target for gemcitabine, have been associated with improved OS in advanced NSCLC patients treated with cisplatin and gemcitabine. Preclinical data and retrospective analyses showed that BRCA1 is able to induce resistance to cisplatin and sensitivity to antimicrotubule agents. In addition, the mRNA levels of expression of RAP80, encoding for a protein cooperating with BRCA1 in homologous recombination (HR), have demonstrated to further sub-classify low BRCA1 NSCLC tumors, improving the predictive model. On the basis of biological knowledge on DNA repair pathway and recent controversial results from clinical validation of potential molecular markers, integrated analysis of multiple DNA repair components could improve predictive information and pave the way to a new approach to customized chemotherapy clinical trials.

Importance of excision repair cross-complementation group 1 and ribonucleotide reductase M1 as prognostic biomarkers in malignant pleural mesothelioma treated with platinum-based induction chemotherapy followed by surgery

OBJECTIVES

Survival and response to platinum-based induction chemotherapy are heterogeneous among patients with malignant pleural mesothelioma. The aim of the present study was to assess the prognostic role of DNA repair markers, such as excision repair cross-complementation group 1 and ribonucleotide reductase M1, in multimodally treated patients with malignant pleural mesothelioma.

METHODS

Tumor tissue of a malignant pleural mesothelioma cohort (n = 107) treated with platinum/gemcitabine (n = 46) or platinum/pemetrexed (n = 61) induction chemotherapy followed by extrapleural pneumonectomy was assembled on a tissue microarray. Immunohistochemical expression of excision repair cross-complementation group 1 (nuclear) and ribonucleotide reductase M1 (nuclear and cytoplasmic) was assessed for its prognostic impact (association with overall survival or freedom from recurrence).

RESULTS

Patients with high nuclear ribonucleotide reductase M1 expression before chemotherapy showed significantly longer freedom from recurrence (P = .03). When specifically analyzed in the subgroup of patients receiving platinum/gemcitabine followed by extrapleural pneumonectomy, high nuclear ribonucleotide reductase M1 was associated with prolonged freedom from recurrence (P = .03) and overall survival (P = .02). Low excision repair cross-complementation group 1 expression in prechemotherapy tumor tissues was associated with significantly longer freedom from recurrence (P = .04). Nuclear ribonucleotide reductase M1 and excision repair cross-complementation group 1 were independent prognosticators of freedom from recurrence in addition to pT stage in multivariate analysis.

CONCLUSIONS

In the present study, nuclear ribonucleotide reductase M1 and excision repair cross-complementation group 1 expression were identified as independent prognosticators for freedom from recurrence of malignant pleural mesothelioma in patients undergoing induction chemotherapy followed by extrapleural pneumonectomy.

Serpin b3 is associated with poor survival after chemotherapy and is a potential novel predictive biomarker in advanced non-small-cell lung cancer

INTRODUCTION

In a previous biomarker discovery project using gene-expression profiling we identified Serpin B3 (SB3) as a predictor of resistance to platinum doublet chemotherapy (PtC) in non-small-cell lung cancer (NSCLC). This independent prospective study was designed to confirm the predictive utility of SB3.

METHODS

SB3 immunohistochemistry was scored by previously validated criteria (score 0 = negative, score 1 = 1%-10% tumor cells positive, score 2 = 11%-50% tumor cells positive, and score 3 = >50% tumor cell positive) in 197 patients with stage IV NSCLC treated with PtC. This provided 80% power to detect a median survival increase from 150 days in patients with an SB3 immunohistochemistry score of 2 or more to 300 days in those with an SB3 score of 0 or 1.

RESULTS

Thirty-six percent of NSCLCs stained positive for SB3. Median survival for SB3 negative/score 0 was 332 days, SB3 positive/score 1 was 268 days, and SB3 positive/score 2 or 3 was 120 days (p = 0.004). Cox proportional hazards analysis demonstrated that SB3 positivity is an independent predictor of survival (hazard ratio = 1.87; 95% confidence interval, 1.29-2.71; p = 0.001).The disease control rate in SB3 score 0, 1 = 65%, and score of 2 or more = 20 % (p = 0.002), with median survival 306 days (score 0, 1) versus 120 days (score ≥ 2, hazard ratio= 1.71; 95% confidence interval. 1.14-3.10; p = 0.002).

CONCLUSIONS

SB3-positive immunohistochemistry score of 2 or more (>10% tumor cells positive) identifies a subgroup of patients with stage IV NSCLC who have a poor survival (median 120 days) when treated with PtC, similar to that estimated for untreated or chemo-refractory stage IV NSCLC. Further prospective qualification using biospecimens from randomized studies is needed, but SB3 seems to be a useful biomarker that identifies a highly resistant subgroup in whom PtC should be avoided.

Overexpression of stathmin 1 is a poor prognostic biomarker in non-small cell lung cancer

Stathmin 1 (STMN1), a major microtubule-depolymerizing protein, is involved in cell cycle progression and cell motility. However, the clinical significance of STMN1 expression in non-small cell lung cancer (NSCLC) has not been determined. The expression pattern of STMN1 mRNA was analyzed by quantitative real-time PCR (qRT-PCR) in 37 cases of NSCLC and in the corresponding non-tumor tissue samples. Furthermore, immunohistochemistry was performed to detect STMN1 protein expression in 113 primary NSCLC tissues. The functional role of STMN1 in lung cancer cell lines was evaluated by small interfering RNA-mediated depletion followed by analyses of cell proliferation and invasion. We found that the STMN1 mRNA and protein levels in NSCLC tissues were significantly higher than those in the corresponding non-tumor tissues (P<0.001). In addition, increased STMN1 expression was correlated with poor tumor differentiation (P<0.001), large tumor size (P=0.022), advanced N stage (P=0.033), and advanced TNM stage (P<0.001). Kaplan-Meier analysis indicates that NSCLC patients with higher STMN1 expression showed significantly worse survival. Moreover, multivariate analysis indicates that higher STMN1 protein expression was an independent prognostic factor of disease-specific survival (HR 2.247, 95%CI 1.320-3.825, P=0.003). Finally, the knockdown of STMN1 in lung cancer cells resulted in a decrease in cellular proliferation and invasion. Our findings suggest that STMN1 may have an important role in NSCLC progression and could serve as a potential prognostic marker for patients with NSCLC.

Pharmacogenomics of cisplatin sensitivity in non-small cell lung cancer

Cisplatin, a platinum-based chemotherapeutic drug, has been used for over 30 years in a wide variety of cancers with varying degrees of success. In particular, cisplatin has been used to treat late stage non-small cell lung cancer (NSCLC) as the standard of care. However, therapeutic outcomes vary from patient to patient. Considerable efforts have been invested to identify biomarkers that can be used to predict cisplatin sensitivity in NSCLC. Here we reviewed current evidence for cisplatin sensitivity biomarkers in NSCLC. We focused on several key pathways, including nucleotide excision repair, drug transport and metabolism. Both expression and germline DNA variation were evaluated in these key pathways. Current evidence suggests that cisplatin-based treatment could be improved by the use of these biomarkers.

Analysis of BIM (BCL-2 like 11 gene) deletion polymorphism in Chinese non-small cell lung cancer patients

BACKGROUND

Drug resistance significantly weakens the efficacy of cancer treatment, and the BIM (also known as the BCL2L11 gene) deletion polymorphism has been identified as a potential biomarker for drug resistance. In this retrospective study, we included a total of 290 patients with advanced non-small cell lung cancer (NSCLC) who received treatment with epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) and chemotherapy.

METHODS

The BIM deletion polymorphism of each patient was detected by polymerase chain reaction. EGFR mutations were detected by denaturing high-performance liquid chromatography methods and the amplification refractory mutation system.

RESULTS

The BIM deletion polymorphism was detected in 45/290 (15.5%) Chinese NSCLC patients. No associations were observed between the BIM deletion and clinic-pathologic characteristics of patients. The BIM deletion polymorphism was predictive of shorter progression-free survival in Chinese patients with EGFR-mutant adenocarcinoma and who were treated with EGFR-TKIs (7.30 vs. 9.53 months, P = 0.034). Additionally, we found that the BIM deletion polymorphism was an effective predictor of short progression-free survival in individuals with EGFR-mutant NSCLC and treated with chemotherapy containing pemetrexed (3.32 vs. 5.30, P = 0.012) or second-/beyond-line chemotherapy containing taxanes (1.53 vs. 2.61 months, P = 0.025). The BIM deletion was not correlated with overall survival.

CONCLUSION

The BIM deletion polymorphism occurs in 15.5% of Chinese NSCLC patients, and is a biomarker for resistance to TKIs and chemotherapy. However, BIM deletion was not a decisive factor in overall survival.

The design and discovery of water soluble 4-substituted-2,6-dimethylfuro[2,3-d]pyrimidines as multitargeted receptor tyrosine kinase inhibitors and microtubule targeting antitumor agents

The design, synthesis and biological evaluations of fourteen 4-substituted 2,6-dimethylfuro[2,3-d]pyrimidines are reported. Four compounds (11-13, 15) inhibit vascular endothelial growth factor receptor-2 (VEGFR-2), platelet-derived growth factor receptor β (PDGFR-β), and target tubulin leading to cytotoxicity. Compound 11 has nanomolar potency, comparable to sunitinib and semaxinib, against tumor cell lines overexpressing VEGFR-2 and PDGFR-β. Further, 11 binds at the colchicine site on tubulin, depolymerizes cellular microtubules and inhibits purified tubulin assembly and overcomes both βIII-tubulin and P-glycoprotein-mediated drug resistance, and initiates mitotic arrest leading to apoptosis. In vivo, its HCl salt, 21, reduced tumor size and vascularity in xenograft and allograft murine models and was superior to docetaxel and sunitinib, without overt toxicity. Thus 21 affords potential combination chemotherapy in a single agent.

The prognostic role of the class III β-tubulin in non-small cell lung cancer (NSCLC) patients receiving the taxane/vinorebine-based chemotherapy: a meta-analysis

Background

A number of studies have examined the relationship between the expression of the class III β-tubulin (TUBB3) and the treatment responses to the taxane/vinorebine-based chemotherapy in patients with non-small cell lung cancer (NSCLC). However, the results of these studies were inconsistent and inconclusive. Therefore, we conducted an up-to-date meta-analysis to evaluate the prognostic role of TUBB3 in the taxane/vinorebine-based chemotherapy.

Methods

A literature search for relevant studies was conducted in PubMed, Embase, and CNKI. The inclusion criteria were the taxane/vinorebine-based chemotherapy in patients with NSCLC and the evaluation of the clinical outcomes in relation to the expression of TUBB3. The clinical outcomes analyzed in this study included the overall response rate (ORR), overall survival (OS), and event-free survival (EFS). Odds ratio (OR) or hazard ratio (HR) with 95% confidence interval (CI) were calculated to assess the risk associated with the TUBB3 expression in the taxane/vinorebine-based chemotherapy.

Results

A total of 28 studies with 2401 NSCLC patients were qualified for this meta-analysis. We found that the positive or high level of TUBB3 expression was associated with a poorer ORR (OR = 0.24, 95% CI = 0.16–0.36, p<0.001), an unfavorable OS (HR = 1.52, 95% CI = 1.27–1.82, p<0.001), and a worse EFS (HR = 1.47, 95% CI = 1.24–1.74, p<0.001) compared to the negative or low level of TUBB3 expression. The statistically significant associations between TUBB3 and chemotherapy responses were also observed in the stratified subgroup analysis, which included the analysis by ethnic subgroup (Asian and Caucasian), chemotherapy regimen (taxane-based and vinorebine-based), TUBB3 detection method (IHC and PCR), and treatment strategy (surgery plus adjuvant chemotherapy and palliative chemotherapy).

Conclusions

The expression level of TUBB3 may be a useful biomarker to predict the clinical outcomes of the taxane/vinorebine-based chemotherapy in patients with NSCLC.

Immunohistochemistry evaluation of biomarker expression in non-small cell lung cancer (Pharmacogenoscan study)

OBJECTIVES

Platinum-based chemotherapy regimens are the standard treatment of non-small cell lung cancer (NSCLC). In this study, our objective was to identify tumor tissue protein biomarkers that might predict a benefit from these treatments.

MATERIALS AND METHODS

The Pharmacogenoscan study prospectively included consecutive chemotherapy-naive NSCLC patients at any stage between 2005 and 2010 at six hospitals in the Rhône-Alpes-Auvergne region of France. Of the 537 patients in the full analysis set, 460 had a complete histological diagnosis. We used the tumor tissue samples for an immunohistochemical evaluation of eight biomarkers: ERCC1, BRCA1, p53, p27kip1, class III β-tubulin (TUBB3), Bax, Fas, and FasL. We looked for associations between these biomarkers and the disease control rate (DCR) after 2/3 cycles of platinum-based chemotherapy, progression-free survival (PFS), and overall survival (OS).

RESULTS

A tissue sample adequate for testing at least one biomarker was available for 289 patients. We found no significant association between biomarker expression levels and clinical or pathological variables; TUBB3 showed a trend toward higher expression in adenocarcinomas (P=0.005). For none of the biomarkers were significant associations found between expression level and DCR, PFS, or OS. TUBB3-negative and FasL-negative tumors showed associations of borderline significance with higher DCR.

CONCLUSION

In a large cohort of patients with predominantly advanced or metastatic NSCLC, none of eight tested immunohistochemical biomarkers predicted the chemotherapy response or survival. Our data indicate limited usefulness of protein biomarkers in metastatic NSCLC and a need for further research based on molecular signatures of greater complexity.

High expression of class III β-tubulin in small cell lung carcinoma

Class III β-tubulin (TUBB3) is emerging as a biomarker in a number of cancers. TUBB3 has been shown to be a prognostic indicator of more aggressive disease and a predictor of resistance to taxanes and vinca alkaloids. To date, there is little data on TUBB3 expression in small cell lung carcinoma (SCLC). The primary objective of this study was to determine the expression of TUBB3 in SCLC. Immunohistochemical staining of SCLC tumor specimens was performed using standard procedures. Expression of TUBB3 was determined as a composite of the percentage of malignant cells staining positive and the intensity of staining. Clinical and tumor data for each patient was compared with the degree of TUBB3 expression. A total of 66 SCLCs were evaluable for TUBB3 expression. The majority of specimens (n=56, 85%) had high expression of TUBB3. Only 4.5% (n=3) had low expression of TUBB3. The mean distribution of positive staining for the specimens was 87.3±1.8% (mean ± SE). Specimens from core biopsies were significantly more likely to have high TUBB3 expression when compared with fine needle aspirates (P=0.004). There were no other significant findings when comparing clinical or tumor characteristics. Overall, we found that expression of TUBB3 in SCLC is higher than expected. Innate resistance to microtubule inhibitors, such as the taxanes and vinca alkaloids, may be associated with this finding. Attempts at microtubule inhibition with novel agents may be able to overcome this resistance mechanism. Further evaluation of TUBB3 as a biomarker in SCLC is warranted.

[Muscle invasive bladder cancer after radical cystectomy. Prognostic factors of adjuvant chemotherapy]

BACKGROUND

The indications to administer adjuvant systemic chemotherapy to patients with urothelial carcinoma of the bladder who underwent radical cystectomy is discussed controversially and all international guidelines are very restrictive with regard to its recommendation for routine daily practice due to the low scientific evidence concerning its therapeutic benefit. Currently, adjuvant systemic chemotherapy should be preferably administered within clinical trials. In the daily routine adjuvant treatment might be given in patients with lymph node positive disease. Clinical, pathohistological and molecular biomarkers which might be associated with a positive or negative treatment response have been evaluated sparsely in the past.

RESULTS

The presence of hemangiosis/lymphangiosis carcinomatosa and/or extranodal expansion in patients with lymph node metastases appears to be associated with a poor outcome. The markers ERCC-1, XAF and anti-apoptotic proteins of the Bcl-2 family seem to represent the most promising biomarkers associated with response to adjuvant cisplatin-based chemotherapy.

Tubulin: an example of targeted chemotherapy

Anticancer drugs directed against the microtubule, including taxanes and vinca alkaloids, have been the backbone of many chemotherapy regimes for decades. These drugs have, however, significant limitations, which have prompted the development of novel microtubule targeting agents (MTAs). This article will discuss MTAs for anticancer therapies and recent debates regarding their mechanisms of action. Furthermore, the limitations of taxanes, including hypersensitivity reactions, neurotoxicity, drug resistance and lack of validated biomarkers to guide therapy will be discussed, all of which have driven the development of novel agents. The mechanisms of action and drug development of new generations of MTAs will also be outlined. Agents demonstrating utility in Phase III clinical trials, including eribulin, ixabepilone, cabazitaxel and trastuzumab-DM1 will be highlighted, as well as novel agents currently in development and future directions for MTAs.

Advances in personalized therapy for lung cancer

INTRODUCTION

Personalized medicine based on tumor characteristics is transforming the management of lung cancer. This review provides an overview of clinically approved strategies to personalize treatment for lung cancer as well as evolving strategies in various stages of clinical development.

AREAS COVERED

Selecting therapy based on various tumor characteristics such as histology and presence of specific molecular alterations will be covered. This review will not only discuss the role of targeted agents in personalizing care for lung cancer but also the strategies to personalize traditional chemotherapeutic agents.

EXPERT OPINION

Advances in genomic medicine to identify key genetic alterations with subsequent development of matching targeted agents are rapidly changing the management of lung cancer. Being able to target key driver molecular aberrations is certainly exciting and clinically meaningful, but only for a limited period of time. Intra- and intertumoral heterogeneity is a major contributor to therapy resistance, a substantial roadblock to durable response. Better understanding of resistance mechanism is at least as important as identifying new targetable genetic changes to effectively advance personalized therapy for lung cancer. Finally, optimization of biopsy specimens and rigorous validation steps to ensure reliability of diagnostic methods would be critical in moving forward.

Ribonucleotide reductase large subunit M1 predicts poor survival due to modulation of proliferative and invasive ability of gastric cancer

OBJECTIVES

We aimed to investigate the prognostic value of RRM1 in GC patients.

METHODS

A total of assessable 389 GC patients with clinicopathological and survival information were enrolled from City of Hope (COH, n = 67) and Zhejiang University (ZJU, n = 322). RRM1 protein expression was determined by immunohistochemistry on FFPE tissue samples. Kaplan-Meier and Cox analyses were used to measure survival. Ras/Raf activity and invasion assays were used to evaluate the role of RRM1 in GC cell lines.

RESULTS

In vitro experiments demonstrated RRM1 activated Ras/Raf/MAPK signal transduction and promoted GC cell proliferation. Meanwhile, RRM1 expression was significantly associated with lymph node involvement, tumor size, Ki67 expression, histological subtype and histological grade in the GC tissue samples (p<0.05). Kaplan-Meier analysis illustrated that high RRM1 expression predicted poor survival in GC patients in the COH and ZJU cohorts (log-rank p<0.01). In multivariate Cox analysis, the hazard ratios of RRM1 for overall survival were 2.55 (95% CI 1.27-5.15) and 1.51 (95% CI 1.07-2.13) in the COH and ZJU sets, respectively. In particular, RRM1 specifically predicted the outcome of advanced GCs with poor differentiation and high proliferative ability. Furthermore, inhibition of RRM1 by siRNA significantly reduced the dNTP pool, Ras/Raf and MMP-9 activities and the levels of p-MEK, p-ERK and NF-κB, resulting in growth retardation and reduced invasion in AGS and NCI-N87 cells.

CONCLUSIONS

RRM1 overexpression predicts poor survival in GC patients with advanced TNM stage. RRM1 could potentially serve as prognostic biomarker and therapeutic target for GCs.

Overexpression of stathmin 1 is associated with poor prognosis of patients with gastric cancer

Recently, stathmin 1 has been proposed to function as an oncogene based on some relevant studies in multiple types of human cancers. However, the role of stathmin 1 in gastric cancer carcinogenesis has not been elucidated yet. The aim of this study was to investigate the expression of stathmin 1 as well as its association with overall survival of gastric cancer patients. The expression of stathmin 1 was detected by real-time quantitative reverse transcription polymerase chain reaction and Western blotting in gastric cancer and adjacent nontumor tissues. In addition, stathmin 1 expression was analyzed by immunohistochemistry in paraffin samples from 210 primary gastric cancer patients. The expression levels of stathmin 1 mRNA and protein in gastric cancer tissues were both significantly higher than those in adjacent nontumor tissues. In addition, the expression of stathmin 1 is correlated with Lauren's classification, depth of invasion, lymph node metastases, and tumor node metastasis (TNM) stage (all P < 0.05). Univariate analysis showed that high stathmin 1 expression was associated with poor prognosis in gastric cancer patients (P = 0.040). Multivariate analysis demonstrated that only lymph node metastasis and TNM stage were the independent prognostic indicators for gastric cancer. Stathmin 1 expression status is not an independent prognostic factor for patients with gastric cancer. Further subgroup analysis revealed that stathmin 1 expression was significantly correlated with prognosis in diffuse type gastric cancer. This research showed that the stathmin 1 overexpression might play an important role in the pathogenesis and subsequent progression of gastric cancer. Stathmin 1 could also be a potential therapeutic target in gastric cancer, especially for diffuse type gastric cancer.

Randomized international phase III trial of ERCC1 and RRM1 expression-based chemotherapy versus gemcitabine/carboplatin in advanced non-small-cell lung cancer

PURPOSE

We assessed whether chemotherapy selection based on in situ ERCC1 and RRM1 protein levels would improve survival in patients with advanced non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Eligible patients were randomly assigned 2:1 to the trial's experimental arm, which consisted of gemcitabine/carboplatin if RRM1 and ERCC1 were low, docetaxel/carboplatin if RRM1 was high and ERCC1 was low, gemcitabine/docetaxel if RRM1 was low and ERCC1 was high, and docetaxel/vinorelbine if both were high. In the control arm, patients received gemcitabine/carboplatin. The trial was powered for a 32% improvement in 6-month progression-free survival (PFS).

RESULTS

Of 331 patients registered, 275 were eligible. The median number of cycles given was four in both arms. A tumor rebiopsy specifically for expression analysis was required in 17% of patients. The median time from informed consent to expression analysis was 11 days. We found no statistically significant differences between the experimental arm and the control arm in PFS (6.1 months v 6.9 months) or overall survival (11.0 months v 11.3 months). A subset analysis revealed that patients with low levels for both proteins who received the same treatment in both treatment arms had a statistically better PFS (P = .02) in the control arm (8.1 months) compared with the experimental arm (5.0 months).

CONCLUSION

This demonstrates that protein expression analysis for therapeutic decision making is feasible in newly diagnosed patients with advanced-stage NSCLC. A tumor rebiopsy is safe, required in 17%, and acceptable to 89% (47 of 53) of patients.

Determination of the optimal tubulin isotype target as a method for the development of individualized cancer chemotherapy

BACKGROUND

As microtubules are essential for cell growth and division, its constituent protein β-tubulin has been a popular target for various treatments, including cancer chemotherapy. There are several isotypes of human β-tubulin and each type of cell expresses its characteristic distribution of these isotypes. Moreover, each tubulin-binding drug has its own distribution of binding affinities over the various isotypes, which further complicates identifying the optimal drug selection. An ideal drug would preferentially bind only the tubulin isotypes expressed abundantly by the cancer cells, but not those in the healthy cells. Unfortunately, as the distributions of the tubulin isotypes in cancer cells overlap with those of healthy cells, this ideal scenario is clearly not possible. We can, however, seek a drug that interferes significantly with the isotype distribution of the cancer cell, but has only minor interactions with those of the healthy cells.

METHODS

We describe a quantitative methodology for identifying this optimal tubulin isotype profile for an ideal cancer drug, given the isotype distribution of a specific cancer type, as well as the isotype distributions in various healthy tissues, and the physiological importance of each such tissue.

RESULTS

We report the optimal isotype profiles for different types of cancer with various routes of delivery.

CONCLUSIONS

Our algorithm, which defines the best profile for each type of cancer (given the drug delivery route and some specified patient characteristics), will help to personalize the design of pharmaceuticals for individual patients. This paper is an attempt to explicitly consider the effects of the tubulin isotype distributions in both cancer and normal cell types, for rational chemotherapy design aimed at optimizing the drug's efficacy with minimal side effects.

Histology as a potential clinical predictor of outcome in advanced non-small-cell lung cancer treated with vinorelbine and mitomycin combination chemotherapy

BACKGROUND

The importance of clinical predictors in the treatment of non-small-cell lung cancer (NSCLC) has increased during the last decade. This retrospective study analyzed the combined patient-level data from two phase II trials that investigated the efficacy and safety of combination chemotherapy with vinorelbine and mitomycin in patients with locally advanced or metastatic NSCLC. The aim of this analysis was to determine if patients' baseline and disease characteristics, including histology, gender, smoking history, and expression of TTF-1, might be potential predictors of outcome.

METHODS

Response rates, unadjusted survival times, and Cox covariate-adjusted hazard ratios (HRs) were calculated. Results were reported separately for each subgroup in each individual trial and in the pooled data set.

RESULTS

A total of 175 patients were included in this analysis. Adjusted HRs for both overall survival (OS) and progression free survival (PFS) favored the nonadenocarcinoma histology subgroup, achieving a statistical significance for OS in the pooled data (n = 175; HR 0.68; 95 % CI 0.49-0.94; p = 0.019). TTF-1-negative immunohistochemistry was associated with a significantly higher response rate (25 vs. 0 %; p = 0.04) and with a nonsignificant advantage in OS (n = 33; HR 1.23; 95 % CI 0.56-2.73; p = 0.608). Gender and smoking history were not strongly related to outcome.

CONCLUSIONS

The results of this analysis indicate that patients with nonadenocarcinoma histology might get superior benefit from combination chemotherapy with vinorelbine and mitomycin. These results should be confirmed in a prospective study.

Expressions of Thymidylate Synthase,Thymidine Phosphorylase, Class III β-tubulin, and Excision Repair Cross-complementing Group 1predict Response in Advanced Gastric Cancer Patients Receiving Capecitabine Plus Paclitaxel or Cisplatin

OBJECTIVE

Toevaluate the role of class III β-tubulin (TUBB3), thymidylate synthase (TS), thymidine phosphorylase (TP), and excision repair cross-complementing group 1 (ERCC1) in clinical outcome of advanced gastric cancer patients receiving capecitabine plus paclitaxel or cisplatin.

METHODS

The clinical data and tumor specimens from 57 advanced gastric cancer patients receiving first-line capecitabine plus paclitaxel (cohort 1, n=36) and capecitabine plus cisplatin (cohort 2, n=21) were retrospectively collected, and TUBB3, TS, TP, and ERCC1 expressions were detected by real-time quantitative PCR. The associations between expressions of biomarkers and response or survival were analyzed statistically.

RESULTS

The median age of 57 patients was 57 years (range: 27-75 years) with 38 males and 19 females. Of all patients, the response rates of patients with high TP, low TP and high TS, low TS expressions were 57.1%, 27.6% (P=0.024), and 55.2%, 28.6% (P=0.042), respectively. Among cohort 1, the response rates and median overall survivals of patients with low and high TUBB3 expressions were 61.1% vs. 33.3% (P=0.095) and 13.8 months vs. 6.6 months (P=0.019), respectively; the response rate (87.5%) of patients with low TUBB3 and high TP expressions was higher than that (14.3%) of patients with high TUBB3 and low TP expressions (P=0.01). Among cohort 2, the response rates of patients with low ERCC1 and high ERCC1 expressions were 45.5% and 20.0% respectively (P=0.361).

CONCLUSION

TUBB3, TS and TP expressions could predict the response of advanced gastric cancer patients receiving capecitabine-based and paclitaxel-based chemotherapy. These results will be further confirmed in future large samples.

Genotyping of stathmin and its association with clinical factors and survival in patients with ovarian cancer

Stathmin is closely correlated with the progression and prognosis of a number of types of human cancer. The present study analyzed the associations between genetic variations in the stathmin gene and clinical outcomes of ovarian cancer. A total of 178 patients with epithelial ovarian cancer were treated with cytoreductive surgery followed by platinum-based chemotherapy. DNA was extracted from fresh tumor samples obtained during surgery. A total of 32 DNA samples were selected randomly for resequencing of the stathmin gene. Tag single nucleotide polymorphisms (SNPs) were identified based on the haplotype model as analyzed by PolyPhred software. Direct sequencing was employed in the genotyping of stathmin in 178 cases. A total of 10 nucleotide variations in stathmin were identified, of which 3 high-frequency variations were known SNPs from databases and 7 were new variations with low frequencies. The tag SNPs rs159531 and rs11376635 were selected from the linkage disequilibrium block of the gene to genotype stathmin in 178 cases. The distribution of the rs159531 genotype in ovarian cancer was 52.8% C/C, 35.4% C/T and 11.2% T/T. The distribution of the rs11376635 genotype in ovarian cancer was 32.0% G/G, 48.3% G/-, 18.5% -/-. The main haplotypes calculated by phase2.0 software were 55.6% CG, 27.8% T-, 15.4% C- and 1.2% TG. However, no associations between the stathmin genotype or haplotype and the outcomes in patients with ovarian cancer were observed. The stathmin genotype and haplotype were not associated with the phenotype of patients with ovarian cancer.

BRCA1 mRNA expression as a predictive and prognostic marker in advanced esophageal squamous cell carcinoma treated with cisplatin- or docetaxel-based chemotherapy/chemoradiotherapy

BACKGROUND

The molecular backgrounds that determine therapeutic effectiveness in esophageal cancer remain largely unknown. Breast cancer susceptibility gene 1 (BRCA1) expression has been found to switch the response to cisplatin- or paclitaxel-based chemotherapy. It remains unclear how variations in BRCA1 expression influence clinical outcomes in esophageal cancer.

PATIENTS AND METHODS

Quantitative real-time polymerase chain reaction (qPCR) was performed to examine BRCA1 mRNA expressions in paraffin-embedded specimens from 144 patients with advanced or metastatic esophageal squamous cell carcinoma who received cisplatin- or docetaxel-based first-line treatments.

RESULTS

Low BRCA1 mRNA expression correlated with increased response rate (RR; P = 0.025 and 0.017, respectively) and median overall survival (mOS; P = 0.002 and P<0.001, respectively) in cisplatin-based chemotherapy or chemoradiotherapy group and also correlated with decreased RR (P = 0.017 and 0.024, respectively) and mOS (both P<0.001) in docetaxel-based chemotherapy or chemoradiotherapy group. Multivariate analysis revealed that low BRCA1 expression was an independent prognostic factor in cisplatin-based chemotherapy (HR 0.29; 95%CI 0.12-0.71; P = 0.007) or chemoradiotherapy (HR 0.12; 95%CI 0.04-0.37; P<0.001) group and higher risk for mortality in docetaxel-based chemotherapy (HR 5.02; 95%CI 2.05-12.28; P<0.001) or chemoradiotherapy (HR 7.02; 95%CI 2.37-27.77; P<0.001) group.

CONCLUSIONS

BRCA1 mRNA expression could be used as a predictive and prognostic marker in esophageal cancer who underwent first-line cisplatin- or docetaxel-based treatments.

Current status and implications of microRNAs in ovarian cancer diagnosis and therapy

Ovarian cancer is the fifth most common cancer among women and causes more deaths than any other type of female reproductive cancer. Currently, treatment of ovarian cancer is based on the combination of surgery and chemotherapy. While recurrent ovarian cancer responds to additional chemotherapy treatments, the progression-free interval becomes shorter after each cycle, as chemo-resistance increases until the disease becomes incurable. There is, therefore, a strong need for prognostic and predictive markers to help optimize and personalize treatment in order to improve the outcome of ovarian cancer. An increasing number of studies indicate an essential role for microRNAs in ovarian cancer progression and chemo-resistance. MicroRNAs (miRNAs) are small endogenous non-coding RNAs (~22bp) which are frequently dysregulated in cancer. Typically, miRNAs are involved in crucial biological processes, including development, differentiation, apoptosis and proliferation. Two families of miRNAs, miR-200 and let-7, are frequently dysregulated in ovarian cancer and have been associated with poor prognosis. Both have been implicated in the regulation of epithelial-to-mesenchymal transition, a cellular transition associated with tumor aggressiveness, tumor invasion and chemo-resistance. Moreover, miRNAs also have possible implications for improving cancer diagnosis; for example miR-200 family, let-7 family, miR-21 and miR-214 may be useful in diagnostic tests to help detect ovarian cancer at an early stage. Additionally, the use of multiple target O-modified antagomirs (MTG-AMO) to inhibit oncogenic miRNAs and miRNA replacement therapy for tumor suppressor miRNAs are essential tools for miRNA based cancer therapeutics. In this review we describe the current status of the role miRNAs play in ovarian cancer and focus on the possibilities of microRNA-based therapies and the use of microRNAs as diagnostic tools.

Hematologic β-tubulin VI isoform exhibits genetic variability that influences paclitaxel toxicity

Cellular microtubules composed of α-β-tubulin heterodimers that are essential for cell shape, division, and intracellular transport are valid targets for anticancer therapy. However, not all the conserved but differentially expressed members of the β-tubulin gene superfamily have been investigated for their role in these settings. In this study, we examined roles for the hematologic isoform β-tubulin VI and functional genetic variants in the gene. β-tubulin VI was highly expressed in blood cells with a substantial interindividual variability (seven-fold variation in mRNA). We characterized DNA missense variations leading to Q43P, T274M, and R307H, and a rare nonsense variant, Y55X. Because variations in the hematologic target of microtubule-binding drugs might alter their myelosuppressive action, we tested their effect in cell lines stably expressing the different β-tubulin VI full-length variants, finding that the T274M change significantly decreased sensitivity to paclitaxel-induced tubulin polymerization. Furthermore, patients treated with paclitaxel and carrying β-tubulin VI T274M exhibited a significantly lower thrombocytopenia than wild-type homozygous patients (P = 0.031). Together, our findings define β-tubulin VI as a hematologic isotype with significant genetic variation in humans that may affect the myelosuppresive action of microtubule-binding drugs. A polymorphism found in a tubulin isoform expressed only in hemapoietic cells may contribute to the patient variation in myelosuppression that occurs after treatment with microtubule-binding drugs.

RPN2 expression predicts response to docetaxel in oesophageal squamous cell carcinoma

BACKGROUND

Neoadjuvant chemotherapy - often using docetaxel in various combinatorial regimens - is a standard treatment choice for advanced oesophageal squamous cell carcinoma (ESCC) in Japan. However, no useful markers exist that predict docetaxel's effects on ESCC. Ribophorin II (RPN2) silencing, which reduces glycosylation of P-glycoproteins and decreases membrane localisation, promotes docetaxel-dependent apoptosis. We investigated whether RPN2 expression in ESCC biopsy specimens could be a predictive biomarker in docetaxel-based neoadjuvant chemotherapy.

METHODS

We evaluated RPN2 expression immunohistochemically in biopsy specimens from 79 patients with node-positive ESCC, who received docetaxel-based adjuvant chemotherapy, and compared clinical and pathological responses between the RPN2-positive and RPN2-negative groups. We also studied susceptibility of RPN2-suppressed ESCC cells to docetaxel.

RESULTS

The RPN2-negative group had better clinical and pathological responses to docetaxel than the RPN2-positive group. We also found RPN2 suppression to alter docetaxel susceptibility in vitro.

CONCLUSION

Expression of RPN2 in biopsy specimens could be a useful predictive marker for response to docetaxel-based neoadjuvant chemotherapy in ESCC.