Gender influences the class III and V β-tubulin ability to predict poor outcome in colorectal cancer

Canine Mammary Tumors: Classification, Biomarkers, Traditional and Personalized Therapies

In recent years, many studies have focused their attention on the dog as a proper animal model for human cancer. In dogs, mammary tumors develop spontaneously, involving a complex interplay between tumor cells and the immune system and revealing several molecular and clinical similarities to human breast cancer. In this review, we summarized the major features of canine mammary tumor, risk factors, and the most important biomarkers used for diagnosis and treatment. Traditional therapy of mammary tumors in dogs includes surgery, which is the first choice, followed by chemotherapy, radiotherapy, or hormonal therapy. However, these therapeutic strategies may not always be sufficient on their own; advancements in understanding cancer mechanisms and the development of innovative treatments offer hope for improved outcomes for oncologic patients. There is still a growing interest in the use of personalized medicine, which should play an irreplaceable role in the research not only in human cancer therapy, but also in veterinary oncology. Moreover, immunotherapy may represent a novel and promising therapeutic option in canine mammary cancers. The study of novel therapeutic approaches is essential for future research in both human and veterinary oncology.

Role of gonadally synthesized steroid hormones in the colorectal cancer microenvironment

Objective

To understand the relationship between steroid hormones synthesized by the gonads and colorectal cancer as well as its tumor microenvironment, in the expectation of providing new ideas in order to detect and treat colorectal cancer.

Methods

Through reviewing the relevant literature at home and abroad, we summarized that androgens promote the growth of colorectal cancer, and estrogens and progesterone help prevent bowel cancer from developing; these three hormones also have a relevant role in the cellular and other non-cellular components of the tumor microenvironment of colorectal cancer.

Conclusion

The current literature suggests that androgens, estrogens, and progesterone are valuable in diagnosing and treating colorectal cancer, and that androgens promote the growth of colorectal cancer whereas estrogens and progesterone inhibit colorectal cancer, and that, in addition, the receptors associated with them are implicated in the modulation of a variety of cellular components of the microenvironment of colorectal cancer.

Profiling estrogen, progesterone, and androgen receptors in colorectal cancer in relation to gender, menopausal status, clinical stage, and tumour sidedness

Background

Although estrogen (ERα/ERβ), progesterone (PGR), and androgen (AR) receptors are pathologically altered in colorectal cancer (CRC), their simultaneous expression within the same cohort of patients was not previously measured.

Methods

ERα/ERβ/PGR/AR proteins were measured in archived paired normal and malignant colon specimens (n =120 patients) by immunohistochemistry, and results were analyzed by gender, age (≤50 vs. ≥60 years), clinical stages (early-stage I/II vs. late-stage III/IV), and anatomical location (right; RSCs vs. left; LSCs). Effects of 17β-estradiol (E2), progesterone (P4), and testosterone alone or combined with the specific blockers of ERα (MPP dihydrochloride), ERβ (PHTPP), PGR (mifepristone), and AR (bicalutamide) on cell cycle and apoptosis were also measured in the SW480 male and HT29 female CRC cell lines.

Results

ERα and AR proteins increased, whilst ERβ and PGR declined markedly in malignant specimens. Moreover, male neoplastic tissues showed highest AR expression, whilst ERβ and PGR weakest alongside ERα strongest expression was seen in cancerous tissues from women aged ≥60 years. Late-stage neoplasms also revealed maximal alterations in the expression of sex steroid receptors. By tumor location, LSCs disclosed significant elevations in ERα with marked declines in PGR compared with RSCs, and ERα strongest alongside PGR weakest expression was detected in advanced LSCs from women aged ≥60 years. Late-stage LSCs from females aged ≥60 years also showed weakest ERβ and strongest AR expression. In contrast, male RSC and LSC tissues exhibited equal ERβ and AR expression in all clinical stages. ERα and AR proteins also correlated positively, whereas ERβ and PGR inversely, with tumor characteristics. Concomitantly, E2 and P4 monotherapies triggered cell cycle arrest and apoptosis in the SW480 and HT29 cells, and while pre-treatment with ERα-blocker enhanced the effects of E2, ERβ-blocker and PGR-blocker suppressed the E2 and P4 anti-cancer actions, respectively. In contrast, treatment with the AR-blocker induced apoptosis, whilst co-treatment with testosterone hindered the effects.

Conclusions

This study advocates that protein expression of sex steroid receptors in malignant tissues could represent prognostic markers, as well as hormonal therapy could provide an alternative strategy against CRC, and their efficacies could be dependent on gender, clinical stage, and tumor location.

βIII-Tubulin Gene Regulation in Health and Disease

Microtubule proteins form a dynamic component of the cytoskeleton, and play key roles in cellular processes, such as vesicular transport, cell motility and mitosis. Expression of microtubule proteins are often dysregulated in cancer. In particular, the microtubule protein βIII-tubulin, encoded by the TUBB3 gene, is aberrantly expressed in a range of epithelial tumours and is associated with drug resistance and aggressive disease. In normal cells, TUBB3 expression is tightly restricted, and is found almost exclusively in neuronal and testicular tissues. Understanding the mechanisms that control TUBB3 expression, both in cancer, mature and developing tissues will help to unravel the basic biology of the protein, its role in cancer, and may ultimately lead to the development of new therapeutic approaches to target this protein. This review is devoted to the transcriptional and posttranscriptional regulation of TUBB3 in normal and cancerous tissue.

OSov: An Interactive Web Server to Evaluate Prognostic Biomarkers for Ovarian Cancer

Simple Summary

The OSov web server incorporates gene expression profiles with clinical risk factors to estimate the ovarian cancers patients’ survival, and provides a tool for multiple analysis, such as forest-plot, uni/multi-variate survival analysis, Kaplan-Meier plot and nomogram construction.

Abstract

Ovarian cancer is one of the most aggressive and highly lethal gynecological cancers. The purpose of our study is to build a free prognostic web server to help researchers discover potential prognostic biomarkers by integrating gene expression profiling data and clinical follow-up information of ovarian cancer. We construct a prognostic web server OSov (Online consensus Survival analysis for Ovarian cancer) based on RNA expression profiles. OSov is a user-friendly web server which could present a Kaplan–Meier plot, forest plot, nomogram and survival summary table of queried genes in each individual cohort to evaluate the prognostic potency of each queried gene. To assess the performance of OSov web server, 163 previously published prognostic biomarkers of ovarian cancer were tested and 72% of them had their prognostic values confirmed in OSov. It is a free and valuable prognostic web server to screen and assess survival-associated biomarkers for ovarian cancer.

βIII-tubulin overexpression in cancer: Causes, consequences, and potential therapies

Class III β-tubulin (βIII-tubulin) is frequently overexpressed in human tumors and is associated with resistance to microtubule-targeting agents, tumor aggressiveness, and poor patient outcome. Understanding the mechanisms regulating βIII-tubulin expression and the varied functions βIII-tubulin may have in different cancers is vital to assess the prognostic value of this protein and to develop strategies to enhance therapeutic benefits in βIII-tubulin overexpressing tumors. Here we gather all the available evidence regarding the clinical implications of βIII-tubulin overexpression in cancer, describe factors that regulate βIII-tubulin expression, and discuss current understanding of the mechanisms underlying βIII-tubulin-mediated resistance to microtubule-targeting agents and tumor aggressiveness. Finally, we provide an overview of emerging therapeutic strategies to target tumors that overexpress βIII-tubulin.

Exosomal TUBB3 mRNA expression of metastatic castration-resistant prostate cancer patients: Association with patient outcome under abiraterone

Background

To use ddPCR to quantify plasma exosomal class III β‐tubulin (βIII‐tubulin, TUBB3, encoded by the TUBB3 gene) mRNA expression in metastatic castration‐resistant prostate cancer (mCRPC) patients, and study the association of this expression with abiraterone efficacy.

Methods

Blood samples were prospectively collected from 52 mCRPC patients using abiraterone as first‐line therapy to measure plasma exosomal TUBB3 mRNA expression value before the initiation of abiraterone. Study endpoints were PSA response rate, PSA‐progression‐free survival (PSA‐PFS), and overall survival (OS, from CRPC to death).

Results

Patients with positive exosomal TUBB3 expression showed shorter PSA‐PFS (negative TUBB3 vs. positive TUBB3: 11.0 vs. 7.9 months; p = 0.014). Further analysis demonstrated that patients with strongly positive exosomal TUBB3 (>20 copies/20 µl) was associated with even shorter PSA‐PFS (negative TUBB3 vs. positive TUBB3 [<20 copies/20 µl] vs. strongly positive TUBB3 [>20 copies/20 µl]: 11.0 vs. 8.3 vs. 3.6 months, p = 0.005). In multivariate analyzes, TUBB3 (+) (HR: 2.114, p = 0.033) and ECOG score >2 (HR: 3.039, p = 0.006) were independent prognosticators of poor PSA‐PFS. PSA response and OS did not present significant differences.

Conclusion

The exosomal TUBB3 mRNA expression level is associated with poor PSA‐PFS of abiraterone in mCRPC patients. The detection of exosomal TUBB3 can be valuable in their management.

MicroRNA-Related Prognosis Biomarkers from High-Throughput Sequencing Data of Colorectal Cancer

Background

Colorectal cancer (CRC) is the third most common cancer in the world, and most of them are adenocarcinomas. CRC could be classified as colon adenocarcinoma (COAD) and rectum adenocarcinoma (READ) according to the original tumorigenesis position. Increasing evidences indicated that microRNAs (miRNAs) play an important role in the occurrence of multiple tumors.

Methods

In this study, we firstly downloaded miRNA (COAD, 8 controls vs. 455 tumors; READ, 3 controls vs. 161 tumors) and mRNA (COAD, 41 controls vs. 478 tumors; READ, 10 controls vs. 166 tumors) data from The Cancer Genome Atlas (TCGA) database and then used DESeq2, RegParallel, miRDB, TargetScanHuman 7.2, DAVID 6.8, STRING, and Cytoscape software to identify the potential prognosis biomarkers.

Results

We identified 175 differential expression miRNAs (DEMs) and 3747 differential expression genes (DEGs) in COAD and 184 DEMs and 3928 DEGs in READ. And then, we obtained 21 (13 in COAD and 8 in READ) DEMs associated with the survival rates, which correlated with 440 (217 in COAD and 223 in READ) overlapping DEGs. Through survival analysis for those overlapping DEGs, we found 11 (8 in COAD and 3 in READ) overlapping DGEs associated with survival rates of patients, which were correlated with 9 (7 in COAD and 2 in READ) DEMs significantly.

Conclusion

In this study, we found several candidate prognostic biomarkers which have been identified in various cancers and also found several new prognosis biomarkers of COAD and READ. In conclusion, this analysis based on theoretical knowledge and clinical outcomes we have done needs further confirmation by more researches.

Association between polymorphisms in PRNCR1 and risk of colorectal cancer in the Saudi population

LncRNA Prostate cancer non-coding RNA (PRNCR1) is downregulated in many types of cancer. The current case-control study was performed on 144 patients with colorectal cancer and 130 matching controls. Genotyping was performed using TaqMan assays for four Single Nucleotide Polymorphisms (SNPs) in PRNCR1. RNAsnp Web Server was used to detect variations in the secondary structure for each SNP. The genotyping analysis for SNP rs1456315 showed increased association with colorectal cancer with the homozygous CC variant allele (OR: 2.09; χ2 = 4.95; CI: 1.08-4.02; p = 0.02), the minor allele frequency, and additive genotype, respectively (OR: 1.55; χ2 = 6.24; CI: 1.09-2.19; p = 0.01) & (OR: 1.64; χ2 = 4.04; CI: 1.01-2.67; p = 0.04). A risk association was also observed among younger age patients (≤57) and in female patients as well as in patients with tumors of the colon. For the other SNPs tested (rs16901946, rs13252298, rs1016343), no significant association was observed. The secondary structure of the rs1456315 mutant is different from that of the wild-type. Our findings suggest that the upregulation of PRNCR1 and its variants is associated with increased risk of colorectal cancer in Saudi patients, indicating that PRNCR1 might be a unique and valuable signature for predicting the risk of colorectal cancer in a Saudi population.

Identification of the Altered Proteins Related to Colon Carcinogenesis by iTRAQ-based Quantitative Proteomic Analysis

Background:

The molecular mechanisms or valuable biomarkers for early diagnosis of colorectal cancer (CRC) are not fully elucidated yet.

Objective:

To understand the proteomic changes at the global level in the carcinogenesis of CRC, differentially expressed proteins between normal intestinal epithelial cells CCD841 and colorectal cancer cells HCT116 were identified.

Method:

The isobaric tags for relative and absolute quantitation (iTRAQ) coupled with 2D LC-MS/MS proteomic approach were performed for screening the altered proteins between cells CCD841 and HCT116.

Results:

A total of 1947 proteins were identified after filtering and using a 1% false discovery rate. Based on a final cutoff (> 3.16 and < 0.32), 229 proteins were found to be significantly altered, among which 95 (41%) were up-regulated while 134 (59%) were down-regulated. Gene Ontology analysis revealed that the differentially expressed proteins were mainly cell part proteins involved in cellular process and binding in terms of subcellular distribution, biological process, and molecular function. KEGG analysis indicated that the differentially expressed proteins were significantly involved in the process of focal adhesion, pathogenic Escherichia coli infection, leukocyte transendothelial migration, bacterial invasion of epithelial cells, regulation of actin cytoskeleton, DNA replication and so on.

Conclusion:

Collectively, our data identified differentially expressed proteins in colon cancer carcinogenesis, which could provide the clues on unraveling the molecular mechanism of CRC.

The Relevance of Gender in Tumor-Influencing Epigenetic Traits

Tumorigenesis as well as the molecular orchestration of cancer progression are very complex mechanisms that comprise numerous elements of influence and regulation. Today, many of the major concepts are well described and a basic understanding of a tumor's fine-tuning is given. Throughout the last decade epigenetics has been featured in cancer research and it is now clear that the underlying mechanisms, especially DNA and histone modifications, are important regulators of carcinogenesis and tumor progression. Another key regulator, which is well known but has been neglected in scientific approaches as well as molecular diagnostics and, consequently, treatment conceptualization for a long time, is the subtle influence patient gender has on molecular processes. Naturally, this is greatly based on hormonal differences, but from an epigenetic point of view, the diverse susceptibility to stress and environmental influences is of prime interest. In this review we present the current view on which and how epigenetic modifications, emphasizing DNA methylation, regulate various tumor diseases. It is our aim to elucidate gender and epigenetics and their interconnectedness, which will contribute to understanding of the prospect molecular orchestration of cancer in individual tumors.

Deguelin induces apoptosis in colorectal cancer cells by activating the p38 MAPK pathway

Objectives

Deguelin, a rotenoid extracted from Mundulea sericea (Leguminosae), exhibits antitumor effects on several types of human cancers. Due to the limited studies of deguelin on colorectal cancer (CRC), the present study was designed to investigate the antitumor effect of deguelin and to explore the underlying mechanism in CRC.

Materials and methods

Cell viability was assessed by the cell counting kit-8 (CCK-8) assay, and cell apoptosis was determined by the annexin v-propidium iodide staining using flow cytometry and Western blot in CRC cell lines after incubation with deguelin. The antitumor effect of deguelin was further evaluated in tumor xenograft models. Moreover, SB203580, a specific inhibitor of p38 MAPK, was used to confirm the involvement of p38 MAPK pathway in deguelin-induced apoptosis.

Results

Deguelin significantly inhibited cell proliferation and induced apoptosis in CRC cell lines (SW620 and RKO) in a time-dependent and dose-dependent manner. Western blot analysis also showed that the expression of proapoptotic proteins (cleaved caspase 3 and cleaved PARP) was upregulated, while that of antiapoptotic proteins (Bcl-2 and survivin) was downregulated after deguelin treatment in CRC cell lines. Moreover, oral administration of deguelin significantly suppressed tumor growth and induced apoptosis in subcutaneous xenograft mouse models without obvious toxicity. Additionally, Western blot revealed that deguelin-induced apoptosis might be regulated by the p38 MAPK pathway and inhibition of p38 MAPK could attenuate deguelin-induced proliferative inhibition and apoptosis in CRC cells.

Conclusion

Collectively, these results demonstrated that deguelin inhibited CRC cell growth by inducing apoptosis via activation of p38 MAPK pathway.

Non-catalytic region of tyrosine kinase adaptor protein 2 (NCK2) pathways as factor promoting aggressiveness in ovarian cancer

BACKGROUND

In this study we investigated the function of the non-catalytic region of tyrosine kinase adaptor protein 2 (NCK2) and its correlation with ITGB1 and ITGB4 integrins in driving ovarian cancer (OvCa) aggressiveness. We also evaluated whether NCK2 may influence prognosis in OvCa patients.

METHODS

Nanofluidic technology was used to analyze expression of NCK2 in 332 OvCa patients. To evaluate mRNA expression of NCK2, integrins and VEGFA in OvCa cell lines, qRT-PCR was performed. Stable NCK2 overexpression was obtained in OVCAR3. qRT-PCR and Western blot were performed to evaluate expression changes of VEGFA, vimentin, ITGB1, ITGB4, MMP2 and MMP9 under normoxia and hypoxia conditions. Coimmunoprecipitation (Co-IP) was performed in the A2780 cell line to study the interaction between NCK2 and proteins of interest. To investigate whether NCK2 can influence anchorage-independent growth, a soft agar assay was completed. Transwell invasion assay was performed on stable-transfected OVCAR-3 cell lines.

RESULTS

Nanofluidic data showed NCK2 can play an important role as a factor promoting tumor aggressiveness and survival in OvCa. This role was also linked to the behaviors of ITGB1 and ITGB4. Moreover, in cells overexpressing NCK2, the expression of vimentin, MMP2, MMP9, VEGFA and ITGB1, but not of ITGB4 was induced by hypoxia. Co-IP showed that NCK2 can directly bind ITGB1, but not VEGFA. NCK2 may be involved in mediating cell-extracellular matrix interactions in OvCa cells by influencing tumor aggressiveness.

CONCLUSIONS

This study provides evidence of a possible role of NCK2 as biomarker of OvCa progression.

Discovery and Validation of Methylation Biomarkers for Ulcerative Colitis Associated Neoplasia

Background and aims

Ulcerative colitis (UC) is associated with a higher background risk of dysplasia and/or neoplasia due to chronic inflammation. There exist few biomarkers for identification of patients with dysplasia, and targeted biopsies in this group of patients are inaccurate in reliably identifying dysplasia. We aimed to examine the epigenome of UC dysplasia and to identify and validate potential biomarkers.

Methods

Colonic samples from patients with UC-associated dysplasia or neoplasia underwent epigenome-wide analysis on the Illumina 450K methylation array. Markers were validated by bisulphite pyrosequencing on a secondary validation cohort and accuracy calculated using logistic regression and receiver-operator curves.

Results

Twelve samples from 4 patients underwent methylation array analysis and 6 markers (GNG7, VAV3, KIF5C, PIK3R5, TUBB6, and ZNF583) were taken forward for secondary validation on a cohort of 71 colonic biopsy samples consisting of normal uninflamed mucosa from control patients, acute and chronic colitis, "field" mucosa in patients with dysplasia/neoplasia, dysplasia, and neoplasia. Methylation in the beta-tubulin TUBB6 correlated with the presence of dysplasia (P < 0.0001) and accurately discriminated between dysplasia and nondysplastic tissue, even in the apparently normal field mucosa downstream from dysplastic lesions (AUC 0.84, 95% CI 0.81-0.87).

Conclusions

Methylation in TUBB6 is a potential biomarker for UC- associated dysplasia. Further validation is needed and is ongoing as part of the ENDCAP-C study.

Impact of sex, age, and ethnicity/race on the survival of patients with rectal cancer in the United States from 1988 to 2012

Most studies report on colon and rectal cancers collectively, even though biologic and prognostic differences exist between these disease entities. Here, we investigated the effects of sex, age, and ethnicity/race on rectal cancer (RC) mortality by stage focusing on differences before and after 2004.Using the SEER database, we identified 105,511 patients diagnosed with RC from 1988-2012. Main outcomes were disease-specific survival (DSS) and overall survival (OS).In patients with stage I-III RC, women achieved a longer DSS (HR 0.87, P < 0.001) than men, independent of age, from 1988-2012. In stage IV disease, the sex disparity favoring women was limited to the age 18-44 yr cohort (DSS HR 0.79, P < 0.001). The sex difference in DSS (Pinteraction = 0.009) was significantly reduced from 2004 to 2012 across all ages. Hispanics and Native Americans with locoregional RC had inferior DSS relative to Whites from 1988-2003, but these differences were not evident from 2004-2012 (Pinteraction = 0.001). Additionally, Asians with stage I-III RC had superior DSS from 2004 on compared to Whites. Mortality in African American patients improved modestly overall and remained significantly higher than other ethnicities/races across all stages.Sex disparities have narrowed in patients with metastatic RC, but persist in patients with stage I-III disease. These differences are most evident among young patients (18-44 years), where sex disparities have even widened in stage I-III disease. While outcomes have improved for Asians, Hispanics, and Native Americans with stage I-III rectal cancer, black-white disparities remain in all disease stages.

The use of surfactants to enhance the solubility and stability of the water-insoluble anticancer drug SN38 into liquid crystalline phase nanoparticles

Cubosomes were used to increase the aqueous solubility of the water insoluble anticancer drug SN38. The results showed that the use of a common cubosome formulation consisting of phytantriol (PHYT) as the matrix amphiphile (PHYT-cubosome) led to a 6-fold increase in the solubility of SN38. However, mean hydrodynamic diameter (D_H) and polydispersity index (PDI) of these PHYT-cubosome particles were 345±49nm and 0.37±0.05, respectively, making them unsuitable for intravenous applications. Several additives were investigated to increase the solubility of SN38 and reduce the D_H and PDI values of the resulting particles. Charged additives such as didodecyldimethyl ammonium bromide (DDAB) and sodium dodecyl sulfate (SDS) led to improvements in the physiochemical properties of the cubosomes. Notably, the PHYT-DDAB and PHT-SDS cubosomes led to 15- and 14-fold increases in the aqueous solubility of SN38, respectively. Moreover, the SN38 loaded into the PHYT-DDAB and PHYT-SDS cubosomes was found to be highly stable, with very little hydrolysis to its inactive acid form. In summary, the addition of DDAB and SDS to PHYT-cubosome nanoparticle drug delivery systems not only led to considerable improvements in their physiochemical properties, but also enhanced the aqueous solubility of SN38 and increased its chemical stability.

Class III β-Tubulin in Colorectal Cancer: Tissue Distribution and Clinical Analysis of Chinese Patients

BACKGROUND Class III β-tubulin (βIII-tubulin) has been reported to express at the invasive margin of colorectal cancer. The present study aimed to investigate the clinical implication of βIII-tubulin expression at the invasive margin of colorectal cancer. MATERIAL AND METHODS We recruited 111 patients with surgically resected colorectal carcinoma for bIII-tubulin expression analysis. The cases with bIII-tubulin-positive tumor cells found only in the invasive front tumor area were assigned to the invasive front group, while the remaining cases were all assigned to the non-invasive front group. Clinical analysis of βIII-tubulin and other clinical data was performed. RESULTS The positive staining rates and staining intensity of bIII-tubulin were significantly different between the invasive and non-invasive front groups (p=0.001 and p=0.006), and there was a significant difference in tumor differentiation between the 2 groups (p=0.032). In the non-invasive front group, staining intensity of bIII-tubulin was significantly associated with positive staining rates and lymphatic metastasis (p<0.001 and p=0.048). CONCLUSIONS Our data showed the tissue distribution of bIII-tubulin expression at invasive margin or diffuse distribution. Expression of bIII-tubulin was correlated with tumor differentiation and lymphatic metastasis, suggesting a potential role of bIII-tubulin in tumor differentiation and metastasis. This study may shed light on bIII-tubulin as a novel potential molecular target for a new anti-cancer drug.

Nitroproteins in Human Astrocytomas Discovered by Gel Electrophoresis and Tandem Mass Spectrometry

Protein tyrosine nitration is involved in the pathogenesis of highly fatal astrocytomas, a type of brain cancer. To understand the molecular mechanisms of astrocytomas and to discover new biomarkers/therapeutic targets, we sought to identify nitroproteins in human astrocytoma tissue. Anti-nitrotyrosine immunoreaction-positive proteins from a high-grade astrocytoma tissue were detected with two-dimensional gel electrophoresis (2DGE)-based nitrotyrosine immunoblots, and identified with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Fifty-seven nitrotyrosine immunopositive protein spots were detected. A total of 870 proteins (nitrated and non-nitrated) in nitrotyrosine-immunopositive 2D gel spots were identified, and 18 nitroproteins and their 20 nitrotyrosine sites were identified with MS/MS analysis. These nitroproteins participate in multiple processes, including drug-resistance, signal transduction, cytoskeleton, transcription and translation, cell proliferation and apoptosis, immune response, phenotypic dedifferentiation, cell migration, and metastasis. Among those nitroproteins that might play a role in astrocytomas was nitro-sorcin, which is involved in drug resistance and metastasis and might play a role in the spread and treatment of an astrocytoma. Semiquantitative immune-based measurements of different sorcin expressions were found among different grades of astrocytomas relative to controls, and a semiquantitative increased nitration level in high-grade astrocytoma relative to control. Nitro-β-tubulin functions in cytoskeleton and cell migration. Semiquantitative immunoreactivity of β-tubulin showed increased expression among different grades of astrocytomas relative to controls and semiquantitatively increased nitration level in high-grade astrocytoma relative to control. Each nitroprotein was rationalized and related to the corresponding functional system to provide new insights into tyrosine nitration and its potential role in the pathogenesis of astrocytoma formation. Graphical Abstract ᅟ.

Tubb3 regulation by the Erk and Akt signaling pathways: a mechanism involved in the effect of arginine ADP-ribosyltransferase 1 (Art1) on apoptosis of colon carcinoma CT26 cells

The influence of the most important classical mono-ADP-ribosyltransferase, arginine ADP-ribosyltransferase 1 (Art1), on survival and apoptosis of colon carcinoma cells and the potential mechanisms have been partly discussed in our previous study but still need to be further studied. In this present study, Art1 of colon carcinoma CT26 cells was silenced with lentiviral vector-mediated short hairpin RNA (shRNA) or overexpressed with lentiviral vector-mediated complementary DNA (cDNA) and allograft transplant tumors are established in Balb/c mice. We verified Art1 knockdown increases apoptosis of CT26 cells transplant tumor; Art1 overexpression acts oppositely. Accordingly, growth of transplant tumors is inhibited in Art1 knockdown transplant tumors and increases in Art1 overexpression transplant tumors. Furthermore, activity of Akt and Erk cell signal pathways and expression of an apoptosis biomarker, βIII-tubulin (Tubb3), decrease when Art1 was silenced and increase when Art1 was overexpressed. Inhibiting Akt pathway or Erk pathway both downregulates expression of Tubb3 on protein and messenger RNA (mRNA) level, indicating that Tubb3 could be regulated by both Akt and Erk pathways, and plays a role in the influence of Art1 on apoptosis of Balb/c mice allograft transplant tumor. We also demonstrated that Bcl-2 family is not the responsible downstream factor of the Erk pathway in colon carcinoma cells which is undergoing apoptosis. These findings enrich the molecular mechanism for the function of Art1 in colon carcinoma and provide a complementary support for Art1 to be a potential therapeutic target of the treatment of this kind of malignant tumor.

Whole genome and transcriptome sequencing of matched primary and peritoneal metastatic gastric carcinoma

Gastric cancer is one of the most aggressive cancers and is the second leading cause of cancer death worldwide. Approximately 40% of global gastric cancer cases occur in China, with peritoneal metastasis being the prevalent form of recurrence and metastasis in advanced disease. Currently, there are limited clinical approaches for predicting and treatment of peritoneal metastasis, resulting in a 6-month average survival time. By comprehensive genome analysis will uncover the pathogenesis of peritoneal metastasis. Here we describe a comprehensive whole-genome and transcriptome sequencing analysis of one advanced gastric cancer case, including non-cancerous mucosa, primary cancer and matched peritoneal metastatic cancer. The peripheral blood is used as normal control. We identified 27 mutated genes, of which 19 genes are reported in COSMIC database (ZNF208, CRNN, ATXN3, DCTN1, RP1L1, PRB4, PRB1, MUC4, HS6ST3, MUC17, JAM2, ITGAD, IREB2, IQUB, CORO1B, CCDC121, AKAP2, ACAN and ACADL), and eight genes have not previously been described in gastric cancer (CCDC178, ARMC4, TUBB6, PLIN4, PKLR, PDZD2, DMBT1and DAB1).Additionally,GPX4 and MPND in 19q13.3-13.4 region, is characterized as a novel fusion-gene. This study disclosed novel biological markers and tumorigenic pathways that would predict gastric cancer occurring peritoneal metastasis.

Overexpression of Class III β-tubulin, Sox2, and nuclear Survivin is predictive of taxane resistance in patients with stage III ovarian epithelial cancer

BACKGROUND

Class III β-tubulin, Sox2, and Survivin play important roles in tumor survival and proliferation. However, the association of these three factors with clinicopathological characteristics, chemoresistance, and survival in patients with ovarian cancer remains controversial.

METHODS

We investigated the predictive value and correlation among the expression levels of Class III β-tubulin, Sox2, and Survivin in 110 patients with stage III ovarian epithelial cancer, including 58 patients who received taxane-based chemotherapy and 52 patients who received non-taxane-based chemotherapy. Expression of these three factors was immunohistochemically examined in 110 ovarian tumor tissues obtained from patients before chemotherapy.

RESULTS

The positive expression rates for Class III β-tubulin, Sox2, and Survivin in ovarian tumor tissues were 59.09 %, 61.82 % and 52.73 %, respectively. The expression of nuclear Survivin and Class III β-tubulin was consistent with that of Sox2 (p = 0.005 and 0.020, respectively). Positive expression of Class III β-tubulin, Sox2, and nuclear Survivin was significantly associated with chemoresistance to taxane-based chemotherapy (p = 0.006, 0.007, and 0.009, respectively), but not to non-taxane-based chemotherapy. Additionally, overexpression of Class III β-tubulin, Sox2, and nuclear Survivin predicted poor progression-free survival in patients receiving taxane-based chemotherapy (p = 0.032, 0.005, and 0.004, respectively).

CONCLUSIONS

These findings suggest that overexpression of Class III β-tubulin, Sox2, and nuclear Survivin might be predictive of taxane resistance and poor progression-free survival in patients with stage III ovarian epithelial cancer. Expression of these three factors may show positive correlations in these patients.

Class III β-tubulin in normal and cancer tissues

Microtubules are polymeric structures composed of tubulin subunits. Each subunit consists of a heterodimer of α- and β-tubulin. At least seven β-tubulin isotypes, or classes, have been identified in human cells, and constitutive isotype expression appears to be tissue specific. Class III β-tubulin (βIII-tubulin) expression is normally confined to testes and tissues derived from neural cristae. However, its expression can be induced in other tissues, both normal and neoplastic, subjected to a toxic microenvironment characterized by hypoxia and poor nutrient supply. In this review, we will summarize the mechanisms underlying βIII-tubulin constitutive and induced expression. We will also illustrate its capacity to serve as a biomarker of neural commitment in normal tissues and as a pure prognostic biomarker in cancer patients.

βIII-Tubulin Regulates Breast Cancer Metastases to the Brain

Brain metastases occur in about 10% to 30% of breast cancer patients, which culminates in a poor prognosis. It is, therefore, critical to understand the molecular mechanisms underlying brain metastatic processes to identify relevant targets. We hypothesized that breast cancer cells must express brain-associated markers that would enable their invasion and survival in the brain microenvironment. We assessed a panel of brain-predominant markers and found an elevation of several neuronal markers (βIII-tubulin, Nestin, and AchE) in brain metastatic breast cancer cells. Among these neuronal predominant markers, in silico analysis revealed overexpression of βIII-tubulin (TUBB3) in breast cancer brain metastases (BCBM) and its expression was significantly associated with distant metastases. TUBB3 knockdown studies were conducted in breast cancer models (MDA-Br, GLIM2, and MDA-MB-468), which revealed significant reduction in their invasive capabilities. MDA-Br cells with suppressed TUBB3 also demonstrated loss of key signaling molecules such as β3 integrin, pFAK, and pSrc in vitro. Furthermore, TUBB3 knockdown in a brain metastatic breast cancer cell line compromised its metastatic ability in vivo, and significantly improved survival in a brain metastasis model. These results implicate a critical role of TUBB3 in conferring brain metastatic potential to breast cancer cells.

Integrated multidimensional analysis is required for accurate prognostic biomarkers in colorectal cancer

CRC cancer is one of the deadliest diseases in Western countries. In order to develop prognostic biomarkers for CRC (colorectal cancer) aggressiveness, we analyzed retrospectively 267 CRC patients via a novel, multidimensional biomarker platform. Using nanofluidic technology for qPCR analysis and quantitative fluorescent immunohistochemistry for protein analysis, we assessed 33 microRNAs, 124 mRNAs and 9 protein antigens. Analysis was conducted in each single dimension (microRNA, gene or protein) using both the multivariate Cox model and Kaplan-Meier method. Thereafter, we simplified the censored survival data into binary response data (aggressive vs. non aggressive cancer). Subsequently, we integrated the data into a diagnostic score using sliced inverse regression for sufficient dimension reduction. Accuracy was assessed using area under the receiver operating characteristic curve (AUC). Single dimension analysis led to the discovery of individual factors that were significant predictors of outcome. These included seven specific microRNAs, four genes, and one protein. When these factors were quantified individually as predictors of aggressive disease, the highest demonstrable area under the curve (AUC) was 0.68. By contrast, when all results from single dimensions were combined into integrated biomarkers, AUCs were dramatically increased with values approaching and even exceeding 0.9. Single dimension analysis generates statistically significant predictors, but their predictive strengths are suboptimal for clinical utility. A novel, multidimensional integrated approach overcomes these deficiencies. Newly derived integrated biomarkers have the potential to meaningfully guide the selection of therapeutic strategies for individual patients while elucidating molecular mechanisms driving disease progression.

PELP1 suppression inhibits colorectal cancer through c-Src downregulation

Proline-, glutamic acid-, and leucine-rich protein 1 (PELP1), a coregulator of estrogen receptors alpha and beta, is a potential protooncogene implicated in several human cancers, including sexual hormone-responsive or sexual hormone-nonresponsive cancers. However, the functions of PELP1 in colorectal cancer remain unclear. In this study, western blot and bioinformatics revealed that PELP1 expression was higher in several colorectal cancer cell lines than in immortalized normal colorectal epithelium. PELP1 silencing by short hairpin RNA promoted the senescence and inhibited the proliferation, colony formation, migration, invasion, and xenograft tumor formation of the CRC cell line HT-29. Moreover, PELP1 silencing was accompanied by c-Src downregulation. c-Src upregulation partly alleviated the damage in HT-29 malignant behavior induced by PELP1 RNA interference. In conclusion, PELP1 exhibits an oncogenic function in colorectal cancer through c-Src upregulation.

Identification alpha-2-HS-glycoprotein precursor and tubulin beta chain as serology diagnosis biomarker of colorectal cancer

BACKGROUND

Colorectal cancer (CRC) remains a major worldwide cause of cancer-related morbidity and mortality largely due to the insidious onset of the disease. The current clinical procedures utilized for disease diagnosis are invasive, unpleasant, and inconvenient. Hence, the need for simple blood tests that could be used for the early detection is crucial for its ultimate control and prevention.

METHODS

The present work is a case-control study focused on proteomic analysis of serum of healthy volunteers and CRC patients by the ClinProt profiling technology based on mass spectrometry. This approach allowed to identifying a pattern of proteins/peptides able to differentiate the studied populations. Moreover, some of peptides differentially expressed in the serum of patients as compared to healthy volunteers were identified by LTQ Orbitrap XL.

RESULTS

A Quick Classifier Algorithm was used to construct the peptidome patterns (m/z 1208, 1467, 1505, 1618, 1656 and 4215) for the identification of CRC from healthy volunteers with accuracy close to 100% (>CEA, P < 0.05). Peaks at m/z 1505 and 1618 were identified as alpha-2-HS-glycoprotein precursor and tubulin beta chain, respectively.

CONCLUSIONS

Alpha-2-HS-glycoprotein precursor and tubulin beta chain could be involved in the pathogenesis of CRC and perform as potential serology diagnosis biomarker.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/4796578761089186.

Association between polymorphisms in long non-coding RNA PRNCR1 in 8q24 and risk of colorectal cancer

BACKGROUND

Genome-wide association studies have identified that genetic variants in 8q24 confer susceptibility to colorectal cancer (CRC). Recently, a novel lncRNA (PRNCR1) that located in the 8q24 was discovered. Single nucleotide polymorphisms (SNPs) in the lncRNAs may influence the process of splicing and stability of mRNA conformation, resulting in the modification of its interacting partners. We hypothesized that SNPs in the lncRNA PRNCR1 may be related to the risk of CRC.

METHODS

We conducted a case-control study and genotyped five tag SNPs in the lncRNA PRNCR1 in 908 subjects including 313 cases with CRC and 595 control subjects using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay.

RESULTS

In overall analyses, we found that the rs13252298 and rs1456315 were associated with significantly decreased risks of CRC. In stratification analyses, we found that CRC patients carrying the rs1456315G were likely to have a tumor size of greater than 5 cm (G vs. A: adjusted OR = 1.56, 95% CI: 1.10-2.23). Additionally, patients with the rs7007694C and rs16901946G had decreased risks to develop poorly differentiated CRC, whereas patients with the rs1456315G had an increased risk to develop poorly differentiated CRC.

CONCLUSION

These findings suggest that SNPs in the lncRNA PRNCR1 may contribute to susceptibility to CRC.

Class III β-tubulin overexpression within the tumor microenvironment is a prognostic biomarker for poor overall survival in ovarian cancer patients treated with neoadjuvant carboplatin/paclitaxel

Critics have suggested that neoadjuvant chemotherapy (NACT) followed by interval debulking may select for resistant clones or cancer stem cells when compared to primary cytoreduction. β-tubulins are chemotherapeutic targets of taxanes and epothilones. Class III β-tubulin overexpression has been linked to chemoresistance and hypoxia. Herein, we describe changes in class III β-tubulin in patients with advanced ovarian carcinoma in response to NACT, in relationship to clinical outcome, and between patients who underwent NACT versus primary debulking; we characterize in vitro chemosensitivity to paclitaxel/patupilone of cell lines established from this patient population, and class III β-tubulin expression following repeated exposure to paclitaxel. Using immunohistochemistry, we observed among 22 paired specimens obtained before/after NACT decreased expression of class III β-tubulin following therapy within stroma (p=0.07), but not tumor (p=0.63). Poor median overall survival was predicted by high levels of class III β-tubulin in both tumor (HR 3.66 [1.11,12.05], p=0.03) and stroma (HR 4.53 [1.28,16.1], p=0.02). Class III β-tubulin expression by quantitative-real-time-polymerase-chain-reaction was higher among patients who received NACT (n=12) compared to primary cytoreduction (n=14) (mean±SD fold-change: 491.2±115.9 vs. 224.1±55.66, p=0.037). In vitro subculture with paclitaxel resulted in class III β-tubulin upregulation, however, cell lines that overexpressed class III β-tubulin remained sensitive to patupilone. Overexpression of class III β-tubulin in patients dispositioned to NACT may thus identify an intrinsically aggressive phenotype, and predict poor overall survival and paclitaxel resistance. Decreases in stromal expression may represent normalization of the tumor microenvironment following therapy. Epothilones warrant study for patients who have received neoadjuvant carboplatin and paclitaxel.

Interaction between docetaxel resistance and castration resistance in prostate cancer: implications of Twist1, YB-1, and androgen receptor

BACKGROUND

Taxanes, including docetaxel, are currently the only cytotoxic chemotherapeutic agents proven to confer survival benefit in patients with castration-resistant prostate cancer (CRPC). However, the merits of taxanes remain modest, and efforts are needed to improve their therapeutic efficacy.

METHODS

We evaluated the sensitivity of prostate cancer cells to various agents using cytotoxicity assays. Gene and protein expression levels were evaluated by quantitative real-time polymerase chain reaction and Western blotting analysis, respectively.

RESULTS

Hydrogen peroxide-resistant and castration-resistant cells that overexpressed Twist1 and Y-box binding protein-1 (YB-1) were cross-resistant to cytotoxic agents, including docetaxel. Twist1 regulated YB-1 expression in prostate cancer cells, supported by the induction of Twist1 and YB-1 by transforming-growth factor-β, which is critical for taxane resistance. Twist1 and/or YB-1 were activated in docetaxel-resistant prostate cancer cells, and YB-1 was activated by docetaxel treatment. Conversely, Twist1 and YB-1 knockdown sensitized prostate cancer cells to cytotoxic agents, including docetaxel. In addition, androgen receptor (AR) knockdown increased cellular sensitivity to docetaxel, though AR expression in docetaxel-resistant LNCaP cells was paradoxically lower than in parental cells. Intriguingly, androgen deprivation treatment was more effective in docetaxel-resistant LNCaP cells compared with parental cells.

CONCLUSIONS

Twist1/YB-1 and AR signaling promote docetaxel resistance in CRPC cells. However, docetaxel-resistant cells were collaterally sensitive to androgen deprivation because of down-regulation of AR expression, suggesting that the therapeutic effect of initial taxane treatment in hormone-naïve prostate cancer may be superior to that of salvage taxane treatment in CRPC.

Gender-specific profiling in SCN1A polymorphisms and time-to-recurrence in patients with stage II/III colorectal cancer treated with adjuvant 5-fluoruracil chemotherapy

This study was designed to analyze the gender-related association between SCN1A polymorphisms (voltage-gated sodium channels; α-subunit) and time-to-recurrence (TTR) in patients with colorectal cancer (CRC) treated with 5-fluoruracil (5-FU)-based adjuvant chemotherapy. We enrolled from a prospective database patients with stage II and III CRC treated with adjuvant 5-FU-based chemotherapy. Genotypes for SCN1A rs3812718 and rs229877 were determined by direct DNA sequencing. One hundred twenty-seven males and 107 females were included in the study. In the univariate and multivariate analysis, the shortest TTR was associated with female patients carrying the rs3812718-TT genotype (hazard ratio (HR): 2.26 (95% confidence interval (CI): 0.89, 5.70), P=0.039) but with male patients carrying the rs3812718-CC genotype (HR: 0.49 (95% CI: 0.18, 1.38), P=0.048). For rs229877 the CT genotype was associated with a trend for shorter TTR in both gender populations. The study validated gender-dependent association between genomic SCN1A rs3812718 polymorphism and TTR in CRC patients treated with adjuvant 5-FU-based chemotherapy. This study confirms that voltage-gated Na+ channels may be a potential therapeutic target and a useful predictive biomarker before 5-FU infusion.

Free testosterone drives cancer aggressiveness: evidence from US population studies

Cancer incidence and mortality are higher in males than in females, suggesting that some gender-related factors are behind such a difference. To analyze this phenomenon the most recent Surveillance, Epidemiology and End Results (SEER) database served to access cancer survival data for the US population. Patients with gender-specific cancer and with limited information were excluded and this fact limited the sample size to 1,194,490 patients. NHANES III provided the distribution of physiologic variables in US population (n = 29,314). Cox model and Kaplan-Meier method were used to test the impact of gender on survival across age, and to calculate the gender-specific hazard ratio of dying from cancer five years following diagnosis. The distribution of the hazard ratio across age was then compared with the distribution of 65 physiological variables assessed in NHANES III. Spearman and Kolmogorov-Smirnov test assessed the homology. Cancer survival was lower in males than in females in the age range 17 to 61 years. The risk of death from cancer in males was about 30% higher than that of females of the same age. This effect was present only in sarcomas and epithelial solid tumors with distant disease and the effect was more prominent in African-Americans than Caucasians. When compared to the variables assessed in the NHANES III study, the hazard ratio almost exactly matched the distribution of free testosterone in males; none of the other analyzed variables exhibited a similar homology. Our findings suggest that male sex hormones give rise to cancer aggressiveness in patients younger than 61 years.

Tubulin-β-III overexpression by uterine serous carcinomas is a marker for poor overall survival after platinum/taxane chemotherapy and sensitivity to epothilones

BACKGROUND

Uterine serous carcinoma (USC) is a subtype of endometrial cancer associated with chemoresistance and poor outcome. Overexpression of tubulin-β-III and p-glycoprotein has been linked to paclitaxel resistance in many cancers but has been undercharacterized among USCs. Epothilones have demonstrated activity in certain paclitaxel-resistant malignancies. In this study, relationships are clarified, in USCs relative to ovarian serous carcinomas (OSCs), between tubulin-β-III and p-glycoprotein expression, clinical outcome, and in vitro chemoresponsiveness to epothilone B, ixabepilone, and paclitaxel.

METHODS

Tubulin-β-III and p-glycoprotein were quantified by real-time polymerase chain reaction in 48 fresh-frozen tissue samples and 13 cell lines. Copy number was correlated with immunohistochemistry and overall survival. Median inhibitory concentration (IC50 ) was determined using viability and metabolic assays. Impact of tubulin-β-III knockdown on IC50 was assessed with small interfering RNAs.

RESULTS

USC overexpressed tubulin-β-III but not p-glycoprotein relative to OSC in both fresh-frozen tissues (552.9 ± 106.7 versus 202.0 ± 43.99, P = .01) and cell lines (1701.0 ± 376.4 versus 645.1 ± 157.9, P = .02). Tubulin-β-III immunohistochemistry reflected quantitative real-time polymerase chain reaction copy number and overexpression stratified patients by overall survival (copy number ≤ 400: 615 days; copy number > 400: 165 days, P = .049); p-glycoprotein did not predict clinical outcome. USCs remained exquisitely sensitive to patupilone in vitro despite tubulin-β-III overexpression (IC50,USC 0.245 ± 0.11 nM versus IC50,OSC 1.01 ± 0.13 nM, P = .006).

CONCLUSIONS

Tubulin-β-III overexpression in USCs discriminates poor prognosis, serves as a marker for sensitivity to epothilones, and may contribute to paclitaxel resistance. Immunohistochemistry reliably identifies tumors with overexpression of tubulin-β-III, and a subset of individuals likely to respond to patupilone and ixabepilone. Epothilones warrant clinical investigation for treatment of USCs.

βIII-Tubulin: biomarker of taxane resistance or drug target?

INTRODUCTION

βIII-Tubulin (TUBB3) is predominantly expressed in neurons of the central and peripheral nervous systems, while in normal non-neoplastic tissues it is barely detectable. By contrast, this cytoskeletal protein is abundant in a wide range of tumors. βIII-Tubulin is linked to dynamic instability of microtubules (MTs), weakening the effects of agents interfering with MT polymerization. Based on this principle, early studies introduced the classical theory linking βIII-tubulin with a mechanism of counteracting taxane activity and accordingly, prompted its investigation as a predictive biomarker of taxane resistance.

AREAS COVERED

We reviewed 59 translational studies, including cohorts from lung, ovarian, breast, gastric, colorectal and various miscellaneous cancers subject to different chemotherapy regimens.

EXPERT OPINION

βIII-Tubulin functions more as a prognostic factor than as a predictor of response to chemotherapy. We believe this view can be explained by βIII-tubulin's association with prosurvival pathways in the early steps of the metastatic process. Its prognostic response increases if combined with additional biomarkers that regulate its expression, since βIII-tubulin can be expressed in conditions, such as estrogen exposure, unrelated to survival mechanisms and without any predictive activity. Additional avenues for therapeutic intervention could emerge if drugs are designed to directly target βIII-tubulin and its mechanism of regulation.

High expression of class III β-tubulin predicts good response to neoadjuvant taxane and doxorubicin/cyclophosphamide-based chemotherapy in estrogen receptor-negative breast cancer

BACKGROUND

Expression of class ΙΙΙ β-tubulin (βΙΙΙ-tubulin) correlates with tumor progression and resistance to taxane-based therapies for several human malignancies including breast cancer. However its predictive value in a neoadjuvant setting in breast cancer remains unexplored. The objective of this explorative study was to determine whether βΙΙΙ-tubulin expression in breast cancer correlated with pathologic characteristics and whether its expression was predictive of response to neoadjuvant chemotherapy.

PATIENTS AND METHODS

We determined βΙΙΙ-tubulin expression in 85 breast cancers, including 41 localized breast cancers treated with primary surgery and 44 treated with neoadjuvant chemotherapy before surgery. βΙΙΙ-tubulin expression was evaluated by immunohistochemical methods and was correlated with pathologic characteristics and response to neoadjuvant chemotherapy using residual cancer burden (RCB) score.

RESULTS

High βΙΙΙ-tubulin expression was significantly associated with poorly differentiated high-grade breast cancers (P = .003) but not with tumor size, estrogen receptor (ER) status, or human epidermal growth factor receptor 2 (HER2)/neu overexpression. In ER(-) tumors treated with neoadjuvant chemotherapy, high βΙΙΙ-tubulin expression was associated with a significantly greater likelihood of achieving a good pathologic response to chemotherapy as reflected by lower RCB scores (P = .021).

CONCLUSION

This study reveals differential βΙΙΙ-tubulin expression in breast cancers of different histologic grades, hormone receptors, and HER2/neu status. It also suggests a potential role for βΙΙΙ-tubulin as a predictive biomarker for response in neoadjuvant chemotherapy for ER(-) breast cancer, which has not been previously reported. These data provide a strong rationale for considering βΙΙΙ-tubulin status and further validation of this marker in a large study.

Pro-survival and anti-apoptotic properties of androgen receptor signaling by oxidative stress promote treatment resistance in prostate cancer

Oxidative stress caused by an increase in reactive oxygen species levels or a decrease in cellular antioxidant capacity can evoke the modulation of various cellular events including androgen receptor (AR) signaling via direct or indirect interactions. In this review, we summarize the mechanisms of AR activation by oxidative stress including: i) AR overexpression; ii) AR activation by AR co-regulators or intracellular signal transduction pathways; iii) generation of AR mutations or splice variants; and iv) de novo androgen synthesis. AR signaling augmented by oxidative stress appears to contribute to pro-survival and anti-apoptotic effects in prostate cancer cells in response to androgen deprivation therapy. In addition, AR signaling suppresses anti-survival and pro-apoptotic effects in prostate cancer cells in response to various cytotoxic and tumor-suppressive interventions including taxanes and radiation through the modulation of βIII-tubulin and ataxia telangiectasia-mutated kinase expression respectively. Taken together, AR signaling appears to render prostate cancer cells refractory to various therapeutic interventions including castration, taxanes, and radiation, indicating that AR signaling is a comprehensive resistant factor and crucial target for prostate cancer treatment.

βV-tubulin expression is associated with outcome following taxane-based chemotherapy in non-small cell lung cancer

Background:

Tubulin-binding agents (TBAs) are effective in non-small cell lung cancer (NSCLC) treatment. Both βIII- and βV-tubulins are expressed by cancer cells and may lead to resistance against TBAs.

Methods:

Pre-treatment samples from 65 locally advanced or oligometastatic NSCLC patients, who underwent uniform induction chemotherapy with paclitaxel and platinum followed by radiochemotherapy with vinorelbine and platinum were retrospectively analysed by immunohistochemistry. Protein expression of βIII- and βV-tubulin was morphometrically quantified.

Results:

Median pre-treatment H-score for βIII-tubulin was 110 (range: 0–290), and 160 for βV-tubulin (range: 0–290). Low βIII-tubulin expression was associated with improved overall survival (OS) (P=0.0127, hazard ratio (HR): 0.328). An association between high βV-tubulin expression and prolonged progression-free survival (PFS, median 19.2 vs 9.4 months in high vs low expressors; P=0.0315, HR: 1.899) was found. Further, high βV-tubulin expression was associated with objective response (median H-score 172.5 for CR+PR vs 120 for SD+PD patients, P=0.0104) or disease control following induction chemotherapy (170 for CR+PR+SD vs 100 for PD patients, P=0.0081), but not radiochemotherapy.

Conclusion:

Expression of βV-tubulin was associated with treatment response and PFS following paclitaxel-based chemotherapy of locally advanced and oligometastatic NSCLC patients. Prolonged OS was associated with low levels of βIII-tubulin. Prospective evaluation of βIII/βV-tubulin expression in NSCLC is warranted.