Immunoprofiles of 11 biomarkers using tissue microarrays identify prognostic subgroups in colorectal cancer

Harnessing HEK293 cell-derived exosomes for hsa-miR-365a-3p delivery: Potential application in hepatocellular carcinoma therapy

Hepatocellular carcinoma (HCC) is the most frequent form of liver malignancy, and curing it is very challenging. Restoring tumor suppressor microRNAs could trigger the initiation of cellular anticancer mechanisms. Exosomes are nanosized biocarriers capable of fusing with cell membranes and delivering their cargo. The main goal of the current study was to explore the potential of human embryonic kidney cells (HEK293) cell-derived exosomes to provide an anticancer therapy based on the restoration of tumor suppressor miR-365a downregulated in HepG2 cells. To accomplish this aim, exosomes were isolated from the HEK293 cell line culture and characterized, enriched by Homo sapiens (hsa) miR-365a-3p mimics. Exosomes enabled an efficient loading and intracellular delivery of hsa-miR-365a mimics, which translated into G0/G1 cell cycle arrest, induction of oxidative stress, reduction of migration capacity, and high apoptosis rate. The findings indicate that the delivery of miR-365a-3p by HEK293-derived exosomes may act as an innovative and effective therapeutic strategy against HCC.

TIM-3 Qualifies as a Potential Immunotherapeutic Target in Specific Subsets of Patients with High-Risk Soft Tissue Sarcomas (HR-STS)

(1) Background: The expression of T cell immunoglobulin and mucin domain-containing protein 3 (TIM-3), an immune checkpoint receptor on T cells, has been associated with dismal outcomes and advanced tumor stages in various solid tumors. The blockade of TIM-3 is currently under examination in several clinical trials. This study examines TIM-3 expression in high-risk soft tissue sarcomas (HR-STS). (2) Methods: Tumor cell expression of TIM-3 on protein level was analyzed in pre-treatment biopsies of patients with HR-STS. TIM-3 expression was correlated with clinicopathological parameters including tumor-infiltrating lymphocyte (TIL) counts, programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PDL-1) expression in patients with HR-STS. Survival dependent on the expression of TIM-3 was analyzed. (3) Results: TIM-3 expression was observed in 101 (56%) out of 179 pre-treatment biopsies of patients with HR-STS. TIM-3 expression was significantly more often observed in undifferentiated pleomorphic sarcomas (UPS) compared to other histological subtypes (p < 0.001), high TIL counts (p < 0.001), and high PD-1 (p < 0.001) and PD-L1 expression (p < 0.001). TIM-3 expression did not have a prognostic impact on survival in patients with HR-STS. (4) Conclusions: This is the first study to demonstrate a significant tumor cell expression of TIM-3 in specific subsets of patients with HR-STS. TIM-3 qualifies as a potential immunotherapeutic target in HR-STS.

The Biochemistry and Physiology of A Disintegrin and Metalloproteinases (ADAMs and ADAM-TSs) in Human Pathologies

Metalloproteinases are a group of proteinases that plays a substantial role in extracellular matrix remodeling and its molecular signaling. Among these metalloproteinases, ADAMs (a disintegrin and metalloproteinases) and ADAM-TSs (ADAMs with thrombospondin domains) have emerged as highly efficient contributors mediating proteolytic processing of various signaling molecules. ADAMs are transmembrane metalloenzymes that facilitate the extracellular domain shedding of membrane-anchored proteins, cytokines, growth factors, ligands, and their receptors and therefore modulate their biological functions. ADAM-TSs are secretory, and soluble extracellular proteinases that mediate the cleavage of non-fibrillar extracellular matrix proteins. ADAMs and ADAM-TSs possess pro-domain, metalloproteinase, disintegrin, and cysteine-rich domains in common, but ADAM-TSs have characteristic thrombospondin motifs instead of the transmembrane domain. Most ADAMs and ADAM-TSs are activated by cleavage of pro-domain via pro-protein convertases at their N-terminus, hence directing them to various signaling pathways. In this article, we are discussing not only the structure and regulation of ADAMs and ADAM-TSs, but also the importance of these metalloproteinases in various human pathophysiological conditions like cardiovascular diseases, colorectal cancer, autoinflammatory diseases (sepsis/rheumatoid arthritis), Alzheimer's disease, proliferative retinopathies, and infectious diseases. Therefore, based on the emerging role of ADAMs and ADAM-TSs in various human pathologies, as summarized in this review, these metalloproteases can be considered as critical therapeutic targets and diagnostic biomarkers.

Pilot proteomic study of locally advanced rectal cancer before and after neoadjuvant chemoradiotherapy indicates high metabolic activity in non-responders' tumor tissue

PURPOSE

In the search for candidate predictive biomarkers to evaluate response to neoadjuvant chemoradiotherapy (nCRT) in rectal cancer, only a few studies report proteomic profiles of tumor tissue before and after nCRT. The aim of our study was to determine differentially expressed proteins between responders and non-responders before and after the therapy in order to identify candidate molecules for prediction and follow-up of response to nCRT.

EXPERIMENTAL DESIGN

The study has included tissue sections of rectal tumor and non-tumor mucosa from five responders and five non-responders taken before and after nCRT from patients with locally advanced rectal cancer. Extracted proteins were analyzed by LC-MS/MS analysis followed by a set of bioinformatics analyses.

RESULT

Proteomics analysis provided a mean of approximately 1050 protein identifications per sample. A comparison of proteomic profiles between responders and non-responders has identified 18 differentially expressed proteins. Pathway analysis demonstrated high metabolic activity in non-responders' tumors before nCRT, indicating the presence of intrinsic chemoradioresistance in these subjects. Two proteins associated with poor prognosis in colorectal cancer, ADAM10 and CAD, were identified as candidate predictive biomarkers as they were present in non-responders only.

CONCLUSIONS AND CLINICAL RELEVANCE

Shortlisted proteins from our study should be further validated as candidate biomarkers for response to routinely applied nCRT protocols.

Gp130 is expressed in pancreatic cancer and can be targeted by the small inhibitor molecule SC144

PURPOSE

Interleukin 6 (IL-6), Oncostatin M (OSM), and downstream effector STAT3 are pro-tumorigenic agents in pancreatic ductal adenocarcinoma (PDAC). Glycoprotein 130 (gp130) is a compound of the IL-6 and OSM receptor complex that triggers STAT3 signaling. SC144 is a small molecule gp130 inhibitor with anticancer activity. This study examines the gp130 expression in human PDAC specimens and the in vitro effects of SC144 in PDAC cell lines.

METHODS

Tissue micro-arrays were constructed from 175 resected human PDAC. The gp130 expression in tumor epithelium and stroma was determined by immunohistochemistry, and survival analysis was performed. Growth inhibition by SC144 was assessed in vitro using BrdU and MTT assays. Western blotting was performed to evaluate the SC144 effect on IL-6 and OSM signaling.

RESULTS

Gp130 was expressed in the epithelium of 78.8% and the stroma of 9.4% of the tumor samples. The median overall survival for patients with or without epithelial gp130 expression was 16.7 months and 15.9 months, respectively (p = 0.830). Patients with no stromal gp130 expression showed poorer survival than patients with stromal gp130 expression (median 16.2 and 22.9 months, respectively), but this difference did not reach significance (p = 0.144). SC144 inhibited cell proliferation and viability and suppressed IL-6- and OSM-stimulated STAT3^Y705 phosphorylation in PDAC cells.

CONCLUSION

Gp130 is expressed in the epithelium of most human PDAC, but stromal expression is rare. The small molecule gp130 inhibitor SC144 potently inhibits PDAC progression in vitro and may abrogate IL-6 or OSM/gp130/STAT3 signaling. These results suggest gp130 as a novel drug target for pancreatic cancer therapy.

ADAM10 and ADAM17 as Biomarkers Linked to Inflammation, Metabolic Disorders and Colorectal Cancer

ADAM10 and ADAM17 have a role in inflammation and diseases associated with inflammation, such as diabetes, cardiovascular diseases (CVD) or cancer, e.g., colorectal cancer (CRC). The aim of this study was to evaluate whether ADAM10 and ADAM17 could be biomarkers of CRC. To achieve this goal, CRC tumors and a surgical margin from 72 patients with CRC were collected. The concentration of ADAM proteins was measured by the ELISA method. Results were analyzed statistically and compared with selected clinical parameters. We found that ADAM17 protein concentration in the tumor samples was higher in patients with diabetes mellitus type 2 (DMT2) (0.28 vs. 0.2 ng/µg protein; p = 0.01) and in the surgical margin was higher both in patients with coexisting DMT2 (0.22 vs. 0.16 ng/µg protein; p < 0.05) and CVD (0.21 vs. 0.13 ng/µg protein; p < 0.01). The concentration of ADAM10 was higher in the surgical margin than in the tumor (249.34 vs. 228.82 pg/µg protein), and the concentration of ADAM17 was higher in the tumor than in the margin (0.23 vs. 0.18 ng/µg protein), but results were not statistically significant. In conclusion, the results of our study indicate that ADAM10 and ADAM17 may be potential biomarkers in cancer linked with DMT2 and CVD as diseases associated with inflammation.

VISTA in Soft Tissue Sarcomas: A Perspective for Immunotherapy?

(1) Background: V domain immunoglobulin suppressor of T cell activation (VISTA) plays a critical role in antitumor immunity and may be a valuable target in cancer immunotherapy. To date, it has never been studied in a large and well-characterised cohort of soft tissue sarcomas (STS). (2) Methods: Using immunohistochemistry, we examined VISTA expression in tumour tissues of 213 high-risk STS. We then analysed whether VISTA was associated with other clinicopathological parameters, including tumour-infiltrating lymphocyte (TIL) counts, programmed death receptor-1 (PD1), programmed death ligand-1 (PDL1), CD3, grading, and long-term survival. (3) Results: We observed VISTA expression in 96 (45%) of 213 specimens with distinct patterns ranging from 26 to 63% for histological subtypes. VISTA was associated with higher grade (G3 vs. G2, p = 0.019), higher TIL counts (p = 0.033), expression of PD1 (p = 0.046), PDL1 (p = 0.031), and CD3+ (p = 0.023). In patients without CD3+ TILs, 10-year survival was higher when VISTA was expressed compared to when there was no VISTA expression (p = 0.013). In a multivariate analysis, VISTA expression was independently associated with prolonged survival (p = 0.043). (4) Conclusions: VISTA is expressed in different STS subtypes and is associated with increased TILs, PD-1, PD-L1, and CD3 expression. Patients with VISTA+ tumours show improved survival. These results may help define future immunotherapeutic approaches in STS.

Adamalizyny jako potencjalne biomarkery w wybranych nowotworach złośliwych przewodu pokarmowego

Nowotwory złośliwe przewodu pokarmowego zajmują czołowe miejsce zarówno wśród przyczyn zachorowań jak i zgonów z powodu chorób nowotworowych na świecie. Wciąż poszukuje się potencjalnych biomarkerów, które mogłyby posłużyć jako czynniki predykcyjne i prognostyczne w tych nowotworach. Wśród białek, które mogłyby pełnić taką rolę, wymienia się adamalizyny. Liczne białka z tej rodziny są zaangażowane w wielu etapach nowotworzenia, od procesu różnicowania się pojedynczych komórek, wzrost i progresję guza do tworzenia przerzutów odległych. Dzieje się to m.in. poprzez ścieżki sygnałowe związane z aktywacją insulinopodobnych czynników wzrostu, naskórkowych czynników wzrostu czy oddziaływanie na czynnik martwicy nowotworu TNF-α. Szczególnie istotna w wyjaśnieniu patomechanizmu rozwoju raków gruczołowych przewodu pokarmowego wydaje się ścieżka sygnałowa związana z aktywacją cytokin prozapalnych. Przewlekły stan zapalny jest bowiem dobrze udokumentowanym czynnikiem ryzyka rozwoju tej grupy chorób nowotworowych.

Poznanie roli białek z rodziny adamalizyn w rozwoju i patogenezie nowotworów złośliwych przewodu pokarmowego wymaga wciąż dalszych badań. W artykule podjęto próbę syntezy aktualnej wiedzy na temat wykorzystania wybranych białek z rodziny adamalizyn jako biomarkerów nowotworów złośliwych przewodu pokarmowego.

Immune infiltrates in patients with localised high-risk soft tissue sarcoma treated with neoadjuvant chemotherapy without or with regional hyperthermia: A translational research program of the EORTC 62961-ESHO 95 randomised clinical trial

BACKGROUND

The EORTC 62961-ESHO 95 randomised trial showed improved long-term survival of patients with high-risk soft-tissue sarcoma by adding regional hyperthermia to neoadjuvant chemotherapy. We hypothesised that immune infiltrate of patients treated with neoadjuvant therapy associate with clinical outcome.

METHODS

Tumour infiltrating lymphocytes (TILs) and CD8, FOXP3, PD-1, and PD-L1 were evaluated in sequential biopsies of patients after four cycles of therapy.

RESULTS

From a subgroup of 109 patients who had been randomised between July 1997 and November 2006 to neoadjuvant chemotherapy (53 patients) or neoadjuvant chemotherapy with regional hyperthermia (56 patients), 137 biopsies were obtained. TILs increased in paired second biopsies independent of treatment allocation (p < 0.001). FOXP3 regulatory T cells decreased (p = 0.002), and PD-L1 expression of tumours became undetectable. In the multivariate analysis, post-treatment high TILs correlated to LPFS (HR: 0.34; 95% CI 0.15-0.75; p = 0.008) and DFS (HR: 0.38; 95% CI 0.17-0.82; p = 0.015). In comparing post-treatment immune infiltrate between treatment arms, tumour response was associated with neoadjuvant chemotherapy with regional hyperthermia (p = 0.013) and high TILs (p = 0.064). High CD8 cell infiltration was associated with improved LPFS (HR: 0.27; 95% CI 0.09-0.79; Log-rank p = 0.011) and DFS (HR: 0.25; 95% CI 0.09-0.73; Log-rank p = 0.006). Improved survival at 10 years was associated with immune infiltrate after neoadjuvant chemotherapy with regional hyperthermia.

CONCLUSION

Preoperative therapy re-programs a non-inflamed tumour at baseline into an inflamed tumour. The post-treatment immune infiltrate became predictive for clinical outcomes. The combination with regional hyperthermia primes the tumour microenvironment, enabling enhanced anti-tumour immune activity in high-risk soft tissue sarcomas.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT00003052.

Expression Patterns of TOP2A and SIRT1 Are Predictive of Survival in Patients with High-Risk Soft Tissue Sarcomas Treated with a Neoadjuvant Anthracycline-Based Chemotherapy

Molecular predictors of response to chemotherapy and survival have not been put into clinical practice in high-risk soft tissue sarcomas (HR-STS) by now. The expression of TOP2A and SIRT1 has implications for the mechanism of action of doxorubicin, which is the backbone of chemotherapy in HR-STS. Pre-treatment samples of 167 patients with HR-STS were collected. Protein expression levels of TOP2A and SIRT1 were evaluated with tissue microarrays and immunohistochemistry and correlated with clinicopathological parameters, including overall survival (OS). The expression of TOP2A and SIRT1 was seen in 47% and 60% of patients with HR-STS, respectively. TOP2A expression was associated with higher tumor grading and shorter 5-year OS. The expression of SIRT1 was correlated with a better 5- and 10-year OS. The combination of high SIRT1 and low TOP2A ("Top survivors") significantly predicted a better OS compared to other biomarker combinations. A multivariate analysis confirmed the expression of SIRT1 and the "Top survivor" biomarker combination as independent predictive factors of OS. This is the first study to associate SIRT1 overexpression with a statistically significant prolongation of OS in HR-STS. Both individual markers and their combination can be used as predictive indicators for HR-STS patients scheduled for neoadjuvant anthracycline-based chemotherapy.

Trop-2 cleavage by ADAM10 is an activator switch for cancer growth and metastasis

Trop-2 is a transmembrane signal transducer that can induce cancer growth. Using antibody targeting and N-terminal Edman degradation, we show here that Trop-2 undergoes cleavage in the first thyroglobulin domain loop of its extracellular region, between residues R87 and T88. Molecular modeling indicated that this cleavage induces a profound rearrangement of the Trop-2 structure, which suggested a deep impact on its biological function. No Trop-2 cleavage was detected in normal human tissues, whereas most tumors showed Trop-2 cleavage, including skin, ovary, colon, and breast cancers. Coimmunoprecipitation and mass spectrometry analysis revealed that ADAM10 physically interacts with Trop-2. Immunofluorescence/confocal time-lapse microscopy revealed that the two molecules broadly colocalize at the cell membrane. We show that ADAM10 inhibitors, siRNAs and shRNAs abolish the processing of Trop-2, which indicates that ADAM10 is an effector protease. Proteolysis of Trop-2 at R87-T88 triggered cancer cell growth both in vitro and in vivo. A corresponding role was shown for metastatic spreading of colon cancer, as the R87A-T88A Trop-2 mutant abolished xenotransplant metastatic dissemination. Activatory proteolysis of Trop-2 was recapitulated in primary human breast cancers. Together with the prognostic impact of Trop-2 and ADAM10 on cancers of the skin, ovary, colon, lung, and pancreas, these data indicate a driving role of this activatory cleavage of Trop-2 on malignant progression of tumors.

ADAM10 is involved in the oncogenic process and chemo-resistance of triple-negative breast cancer via regulating Notch1 signaling pathway, CD44 and PrPc

Background

Triple-negative breast cancer (TNBC) is the most challenging breast cancer subtype to treat, because it is so aggressive with shorter survival. Chemotherapy remains the standard treatment due to the lack of specific and effective molecular targets. The aim of the present study is to investigate the potential roles of A Disintegrin and Metalloproteinase 10 (ADAM10) on TNBC cells and the effects of combining ADAM10 expression and neoadjuvant chemotherapy treatment (NACT) to improve the overall survival in breast cancer patients.

Methods

Using a series of breast cancer cell lines, we measured the expression of ADAM10 and its substrates by quantitative real-time PCR assay (qRT-PCR) and western blot analysis. Cell migration and invasion, cell proliferation, drug sensitivity assay, cell cycle and apoptosis were conducted in MDA-MB-231 cells cultured with ADAM10 siRNA. The effect of ADAM10 down-regulation by siRNA on its substrates was assessed by western blot analysis. We performed immunohistochemical staining for ADAM10 in clinical breast cancer tissues in 94 patients receiving NACT.

Results

The active form of ADAM10 was highly expressed in TNBC cell lines. Knockdown of ADAM10 in MDA-MB-231 cells led to a significant decrease in cell proliferation, migration, invasion and the IC₅₀ value of paclitaxel and adriamycin, while induced cell cycle arrest and apoptosis. And these changes were correlated with down-regulation of Notch signaling, CD44 and cellular prion protein (PrPc). In clinical breast cancer cases, a high ADAM10 expression in pre-NACT samples was strongly associated with poorer response to NACT and shorter overall survival.

Conclusions

These data suggest the previously unrecognized roles of ADAM10 in contributing to the progression and chemo-resistance of TNBC.

ADAM10 expression in gastric adenocarcinoma: Results of a curative gastrectomy cohort

Objective:

Gastric cancer is among the most common human cancers with high mortality rates. ADAM10, a member of the ADAM (a disintegrin and metalloproteinase) family has also been found to be associated with gastric carcinoma and has been suggested as a potential therapeutic target. Here, we investigated the association of ADAM10 expression with prognosis in gastric adenocarcinoma patients that underwent gastric resection with D2 lymph node dissection.

Methods:

Total 86 consecutive patients that underwent resection for gastric adenocarcinoma were included. Immunohistochemical ADAM10 expression and its association with clinicopathological parameters were analyzed. Univariate and multivariate analyses and survival analyses were performed using SPSS ver.22.

Results:

High grade tumors, advanced stage tumors and diffuse type tumors showed significantly worse prognosis. A statistically significant association between ADAM10 expression and overall survival (OS) was observed in the univariate analysis, however, this association did not maintain its significance in the multivariate analysis. No statistically significant association was found ADAM-10 expression and clinicopathological parameters.

Conclusion:

Immunohistochemical ADAM10 expression may be used as a prognostic marker in gastric adenocarcinoma, however, introduction of a standardized immunohistochemical scoring system seems to be necessary for evaluation of ADAM10 staining.

Extracellular Matrix Mechanical Properties and Regulation of the Intestinal Stem Cells: When Mechanics Control Fate

Intestinal stem cells (ISC) are crucial players in colon epithelium physiology. The accurate control of their auto-renewal, proliferation and differentiation capacities provides a constant flow of regeneration, maintaining the epithelial intestinal barrier integrity. Under stress conditions, colon epithelium homeostasis in disrupted, evolving towards pathologies such as inflammatory bowel diseases or colorectal cancer. A specific environment, namely the ISC niche constituted by the surrounding mesenchymal stem cells, the factors they secrete and the extracellular matrix (ECM), tightly controls ISC homeostasis. Colon ECM exerts physical constraint on the enclosed stem cells through peculiar topography, stiffness and deformability. However, little is known on the molecular and cellular events involved in ECM regulation of the ISC phenotype and fate. To address this question, combining accurately reproduced colon ECM mechanical parameters to primary ISC cultures such as organoids is an appropriated approach. Here, we review colon ECM physical properties at physiological and pathological states and their bioengineered in vitro reproduction applications to ISC studies.

Cancer Testis Antigens and Immunotherapy: Expression of PRAME Is Associated with Prognosis in Soft Tissue Sarcoma

(1) Background: PRAME, NY-ESO-1, and SSX2 are cancer testis antigens (CTAs), which are expressed in testicular germ cells with re-expression in numerous cancer types. Their ability to elicit humoral and cellular immune responses have rendered them promising targets for cancer immunotherapy, but they have never been studied in a large and well-characterised cohort of soft tissue sarcomas (STS). (2) Methods: On a protein level, we examined PRAME, NY-ESO-1, and SSX2 expression in tumour tissues of 249 high-risk STS using immunohistochemistry. We correlated expression levels with clinicopathological parameters including tumour-infiltrating lymphocyte (TIL) counts, grading, and long-term survival. (3) Results: Expression of PRAME, NY-ESO-1, and SSX2 was observed in 25 (10%), 19 (8%), and 11 (4%) of 249 specimens with distinct patterns for histo-subtypes. Expression of PRAME was associated with shorter patient survival (p = 0.005) and higher grade (G2 vs. G3, p = 0.001), while NY-ESO-1 expression was correlated with more favourable survival (p = 0.037) and lower grade (G2 vs. G3, p = 0.029). Both PRAME and NY-ESO-1 expression were more frequent in STS with low TIL counts. In multivariate analysis, high PRAME and low SSX2 expression levels as well as metastatic disease and non-radical resections were independent predictors of shorter overall survival. (4) Conclusions: CTAs PRAME, NY-ESO-1, and SSX2 show distinct expression patterns in different STS subtypes. These results demonstrate their prognostic relevance and may guide future immunotherapeutic approaches in STS.

Distinct Expression Patterns of VEGFR 1-3 in Gastroenteropancreatic Neuroendocrine Neoplasms: Supporting Clinical Relevance, but not a Prognostic Factor

INTRODUCTION

Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are an increasing tumor entity. Since many patients are diagnosed at an advanced stage, treatment is still challenging and dependent on many tumor and patient specific factors. Therefore, the aim of the present study was to elucidate the expression rates and the prognostic value of vascular endothelial growth factor receptor (VEGFR) 1-3 in GEP-NENs. A potential association to immune checkpoint markers was further investigated.

MATERIAL AND METHODS

The expression levels of VEGFR 1-3 were analyzed by immunohistochemistry and correlated with the expression of the checkpoint markers PD-1 and PD-L1. Furthermore, the tumor samples of 249 GEP-NEN patients were studied and correlated with overall survival rates and clinicopathological features. Kaplan-Meier analyses and the log rank test were used for survival analyses. Categorical variables were compared by the χ2 test.

RESULTS

The most common primary tumor site was the small intestine (50.6%), followed by the pancreas (25.7%). VEGFR 1 was highly expressed in 59%, VEGFR 2 in 6.4%, and VEGFR 3 in 61.8% of the analyzed samples. The expression of VEGFR 1-3 was not significantly associated with survival rates. Pancreatic NENs had the highest expression of VEGFR 1 and 3 in 80% of the cases. VEGFR 1-3 positivity correlated with the expression levels of immune checkpoint markers.

DISCUSSION

VEGFR 1-3 show a distinct expression pattern in different subgroups of neuroendocrine neoplasias indicating a conceivable target. Moreover, there was a substantial association between VEGFRs and immune checkpoint markers. Taken together, anti-VEGFR therapy represents a promising therapeutic approach in GEP-NEN patients and should be addressed in future studies.

High GJB2 mRNA expression and its prognostic significance in lung adenocarcinoma: a study based on the TCGA database

Lung adenocarcinoma (LUAD), a form of lung cancer, is reported to cause first and second-order cancer morbidity to men and women in China, respectively. We assessed the mRNA expression of GJB2 in LUAD patients in our study, based on data acquired from the cancer genome atlas (TCGA) and so as to increase further knowledge into the biological pathways involved in LUAD pathogenesis related to GJB2.Information on gene expression and comparing clinical data were recognized and downloaded from TCGA. Gene set enrichment analysis (GSEA) created an arranged list of all genes is indicated by their connection with GJB2 expression.Our study cohort included 265 (54.5%) female and 221 (36.0%) male patients. The scatter plot and paired plot showed the difference of GJB2 expression between normal and tumor samples (P < .01). Overall survival (OS) analysis demonstrated that LUAD with GJB2 -high had a more terrible prognosis than that with GJB2 -low (P < .01). Multivariate analysis with the cox proportional hazards model indicated that the expression of Cx26 (HR: 1.00; 95%CI: 1.00-1.01; P = .041) and stage (HR: 1.95; 95%CI: 1.23-3.09; P = .003) were independent prognostic factors for patients with LUAD. The GSEA results showed that cytosolic DNA sensing pathway, apoptosis, cytokine-cytokine receptor interaction, natural killer cell mediated cytotoxicity, regulation of actin cytoskeleton, toll-like receptor signaling pathway, small cell lung cancer and pathways in cancer are differentially enriched in GJB2 high expression phenotype.Our study confirmed the significantly high levels of Cx26 expression in LUAD patients with several observed clinical features. GJB2 may be a potentially useful prognostic molecular biomarker of bad survival in LUAD, while further experimental ought to be performed to demonstrate the biologic effect of GJB2.

Connexins in cancer: bridging the gap to the clinic

Gap junctions comprise arrays of intercellular channels formed by connexin proteins and provide for the direct communication between adjacent cells. This type of intercellular communication permits the coordination of cellular activities and plays key roles in the control of cell growth and differentiation and in the maintenance of tissue homoeostasis. After more than 50 years, deciphering the links among connexins, gap junctions and cancer, researchers are now beginning to translate this knowledge to the clinic. The emergence of new strategies for connexin targeting, combined with an improved understanding of the molecular bases underlying the dysregulation of connexins during cancer development, offers novel opportunities for clinical applications. However, different connexin isoforms have diverse channel-dependent and -independent functions that are tissue and stage specific. This can elicit both pro- and anti-tumorigenic effects that engender significant challenges in the path towards personalised medicine. Here, we review the current understanding of the role of connexins and gap junctions in cancer, with particular focus on the recent progress made in determining their prognostic and therapeutic potential.

Expression of phosphorylated estrogen receptor beta is an independent negative prognostic factor for pancreatic ductal adenocarcinoma

PURPOSE

The role of estrogen receptor beta (ER-β) expression in pancreatic ductal adenocarcinoma (PDAC) is largely unknown. Ligand-independent phosphorylation and activation of ER-β may play a relevant role in the IL-6/STAT3 signaling pathway and, as a result, in tumor progression. Here, we examined the effect of ER-β, phosphorylated ER-β (pER-β), STAT3, phosphorylated STAT3 (pSTAT3) and IL-6 expression on the overall and recurrence-free survival in a cohort of patients with resected PDAC.

METHODS

We identified 175 patients who underwent pancreatic resection for PDAC. Tissue microarrays were constructed from the archival tumor specimens. These were stained with specific antibodies for the above molecules. The expression of the markers was then correlated with clinicopathological parameters and survival analysis was performed.

RESULTS

High nuclear expression of ER-β was found in 61.7% and pER-β in 80.6% of the tumors. STAT3 was expressed in 54.3% of the tumor samples, pSTAT3 in 68% and IL-6 in 76.6%. The median overall survival for patients with low pER-β expression was 29 months, whereas for patients with high pER-β expression was 15.1 months (p = 0.016). Multivariate analysis revealed that pER-β expression was an independent factor correlating with shorter overall survival (hazard ratio 1.9; p = 0.013) and disease-free survival (hazard ratio 1.9; p = 0.029).

CONCLUSIONS

Expression of pER-β constitutes an independent prognostic marker for PDAC and is correlated with poor prognosis. These data may help in identifying novel drug targets in PDAC and patients who could benefit from additional therapeutic regimens, including selective estrogen receptor modulators.

Tropomyosin receptor kinase: a novel target in screened neuroendocrine tumors

Tropomyosin receptor kinase (Trk) inhibitors are investigated as a novel targeted therapy in various cancers. We investigated the in vitro effects of the pan-Trk inhibitor GNF-5837 in human neuroendocrine tumor (NET) cells. The human neuroendocrine pancreatic BON1, bronchopulmonary NCI-H727 and ileal GOT1 cell lines were treated with GNF-5837 alone and in combination with everolimus. Cell viability decreased in a time- and dose-dependent manner in GOT1 cells in response to GNF-5837 treatment, while treatment in BON1 and NCI-H727 cells showed no effect on cellular viability. Trk receptor expression determined GNF-5837 sensitivity. GNF-5837 caused downregulation of PI3K-Akt-mTOR signaling, Ras-Raf-MEK-ERK signaling, the cell cycle and increased apoptotic cell death. The combinational treatment of GNF-5837 with everolimus showed a significant enhancement in inhibition of cell viability vs single substance treatments, due to a cooperative PI3K-Akt-mTOR and Ras-Raf-MEK-ERK pathway downregulation, as well as an enhanced cell cycle component downregulation. Immunohistochemical staining for Trk receptors were performed using a tissue microarray containing 107 tumor samples of gastroenteropancreatic NETs. Immunohistochemical staining with TrkA receptor and pan-Trk receptor antibodies revealed a positive staining in pancreatic NETs in 24.2% (8/33) and 33.3% (11/33), respectively. We demonstrated that the pan-Trk inhibitor GNF-5837 has promising anti-tumoral properties in human NET cell lines expressing the TrkA receptor. Immunohistochemical or molecular screening for Trk expression particularly in pancreatic NETs might serve as predictive marker for molecular targeted therapy with Trk inhibitors.

Serological immune response against ADAM10 pro-domain is associated with favourable prognosis in stage III colorectal cancer patients

A humoral immune response against aberrant tumor proteins can be elicited in cancer patients, resulting in the production of auto-antibodies (Abs). By serological proteome analysis we identified the surface membrane protein ADAM10, a metalloproteinase that has a role in epithelial-tumor progression and invasion, as a target of the immune response in colorectal cancer (Crc). A screening carried out on the purified protein using testing cohorts of sera (Crc patients n = 57; control subjects n = 39) and validation cohorts of sera (Crc patients n = 49; control subjects n = 52) indicated that anti-ADAM10 auto-Abs were significantly induced in a large group (74%) of colon cancer patients, in particular in patients at stage II and III of the disease. Interestingly, in Crc patients classified as stage III disease, the presence of anti-ADAM10 auto-Abs in the sera was associated with a favourable follow-up with a significant shifting of the recurrence-free survival median time from 23 to 55 months. Even though the ADAM10 protein was expressed in Crc regardless the presence of auto-Abs, the immature/non-functional isoform of ADAM10 was highly expressed in the tumor of anti-ADAM10-positive patients and was the isoform targeted by the auto-Abs. In conclusion, the presence of anti-ADAM10 auto-Abs seems to reflect the increased tumor expression of the immunogenic immature-ADAM10 in a group of Crc patients, and is associated with a favourable prognosis in patients at stage III of the disease.

The role of gap junctions in inflammatory and neoplastic disorders (Review)

Gap junctions are intercellular channels made of connexin proteins, mediating both electrical and biochemical signals between cells. The ability of gap junction proteins to regulate immune responses, cell proliferation, migration, apoptosis and carcinogenesis makes them attractive therapeutic targets for treating inflammatory and neoplastic disorders in different organ systems. Alterations in gap junction profile and expression levels are observed in hyperproliferative skin disorders, lymphatic vessel diseases, inflammatory lung diseases, liver injury and neoplastic disorders. It is now recognized that the therapeutic effects mediated by traditional pharmacological agents are dependent upon gap junction communication and may even act by influencing gap junction expression or function. Novel strategies for modulating the function or expression of connexins, such as the use of synthetic mimetic peptides and siRNA technology are considered.

VEGFR2 predicts decreased patients survival in soft tissue sarcomas

AIMS

Tyrosine kinases are promising targets for personalized medicine, and new drugs are currently in phase 2 and phase 3 clinical trials. However, expression analysis of tyrosine kinases as predictive biomarkers is still not a standard approach. Furthermore, only limited studies have investigated the expression of tyrosine kinase receptors on the protein level. In this study, we analysed a well-characterised group of soft tissue sarcomas for different tyrosine kinase receptors and correlated the results with clinicopathological parameters, including survival.

METHODS

275 soft tissue sarcomas of our Sarcoma center at the Ludwig-Maximilians-University (LMU) were reinvestigated and categorized according to the current WHO classification system. The tumor collective included undifferentiated pleomorphic sarcomas (n=81), leiomyosarcomas (n=50), synovial sarcomas (n=27), liposarcomas (n=51), angiosarcomas (n=43) and other soft tissue sarcomas (n=23).

RESULTS

On protein levels, high expression of VEGFR1 was detected immunohistochemically in 61%, VEGFR2 (KDR) in 11%, VEGFR3 in 64%, PDGFRA in 42% and PDGFRB in 73%. High expression of VEGFR1-3 and PDGFRB was significantly correlated with higher grading (G2 vs G3, p<0.05), and high VEGFR2 was significantly correlated with decreased patients' survival (p<0.001).

CONCLUSIONS

Tyrosine kinase receptors showed a distinct expression pattern in soft tissue sarcomas. High expression of VEGFR2 (KDR) is significantly associated with decreased patients' survival. High VEGFR 1-3 and PDGFRB are significantly correlated with higher tumor grading. Protein signatures might be evaluated before targeted therapy to give a rationale for an eligible personalized therapy.

Subcellular localization and activation of ADAM proteases in the context of FasL shedding in T lymphocytes

The "A Disintegrin And Metalloproteinases" (ADAMs) form a subgroup of the metzincin endopeptidases. Proteolytically active members of this protein family act as sheddases and govern key processes in development and inflammation by regulating cell surface expression and release of cytokines, growth factors, adhesion molecules and their receptors. In T lymphocytes, ADAM10 sheds the death factor Fas Ligand (FasL) and thereby regulates T cell activation, death and effector function. Although FasL shedding by ADAM10 was confirmed in several studies, its regulation is still poorly defined. We recently reported that ADAM10 is highly abundant on T cells whereas its close relative ADAM17 is expressed at low levels and transiently appears at the cell surface upon stimulation. Since FasL is also stored intracellularly and brought to the plasma membrane upon stimulation, we addressed where the death factor gets exposed to ADAM proteases. We report for the first time that both ADAM10 and ADAM17 are associated with FasL-containing secretory lysosomes. Moreover, we demonstrate that TCR/CD3/CD28-stimulation induces a partial positioning of both proteases and FasL to lipid rafts and only the activation-induced raft-positioning results in FasL processing. TCR/CD3/CD28-induced FasL proteolysis is markedly affected by reducing both ADAM10 and ADAM17 protein levels, indicating that in human T cells also ADAM17 is implicated in FasL processing. Since FasL shedding is affected by cholesterol depletion and by inhibition of Src kinases or palmitoylation, we conclude that it requires mobilization and co-positioning of ADAM proteases in lipid raft-like platforms associated with an activation of raft-associated Src-family kinases.

Vascular endothelial growth factor receptor isoforms: are they present in oral squamous cell carcinoma?

PURPOSE

Although the clinical importance of vascular endothelial growth factor (VEGF) overexpression in oral squamous cell carcinoma (OSCC) has been investigated, there are limited data about the overexpression of VEGF receptors (VEGF-Rs) and their clinical importance. VEGF-R isoforms have proven influence on proliferation rates, metastasis, and survival in different neoplasms. This study was conducted to investigate VEGF-R expression levels in OSCC samples and to identify any clinical relevance.

MATERIALS AND METHODS

A retrospective cohort study design (n = 50) was used. Clinical data were gathered from patient charts. Validated immunohistochemical methods were applied to determine VEGF-R isoform expression by tumor cells. Descriptive and inferential statistics with respect to the variable scale were computed. The significance level was set at a P value less than or equal to .05.

RESULTS

This study found overexpression of different VEGF-R isoforms in 88% of examined specimens. Statistically important associations were detected between overexpression of specific VEGF-Rs and tumor size, neck node metastasis, and tumor-associated death. Furthermore, a history of common OSCC risk factors (smoking and alcohol consumption) were found considerably more often in patients whose OSCC specimens displayed VEGF-R overexpression.

CONCLUSION

These findings show that VEGF-R overexpression occurs frequently in OSCC and could have clinical implications.

High IGF2 and FGFR3 are associated with tumour progression in undifferentiated pleomorphic sarcomas, but EGFR and FGFR3 mutations are a rare event

AIM

Pleomorphic undifferentiated sarcomas (formerly known as malignant fibrous histiocytomas) are recognised by the actual WHO classification as an undifferentiated, unclassifiable category of pleomorphic sarcomas which show no definable line of differentiation and are still a diagnosis of exclusion. Therefore, diagnostic, prognostic and therapeutic options of these tumours are urgently needed.

METHODS

Three hundred and twenty-seven spindle cell tumours of a German consultation and reference centre of soft tissue tumours consisting of 200 undifferentiated pleomorphic sarcomas (UPS), 45 low-grade sarcomas (10 low-grade fibromyxoid sarcomas, 32 low-grade myofibroblastic sarcomas and three myxoinflammatory fibroblastic sarcomas) and 82 tumours of the fasciitis family were revisited. The specimens were analysed immunohistochemically with distinct markers including tyrosine kinases and expression correlated with clinicopathological parameters. Additionally, mutational analysis was performed on specimens with high expression of EGFR and FGFR3.

RESULTS

At the protein level high IGF2 expression was observed in 86 %, FGFR3 (69 %), PDGFRA (62 %), PDGFRB (39 %), FGFR1 (8 %), EGFR (5 %), KDR/VEGFR2 (3 %), ALK (0 %) and high Ki67 (63 %) in UPS. High expressions of IGF2 and FGFR3 are significantly correlated with a higher grading (p = 0.023 and p = 0.016, respectively) and a high Ki67 index (p = 0.017 and p = 0.001, respectively). No mutations were found in the hot spots of tumour specimens with a high expression of EGFR gene (exons 18-21) and FGFR3 gene (exons 7, 10 and 15).

CONCLUSIONS

High expressions of IGF2 and FGFR3 are significantly associated with tumour progression, grading and Ki67 and might classify a subgroup of undifferentiated pleomorphic sarcoma. These markers might guide targeted therapies in these neoplasms.

Connexins in colorectal cancer pathogenesis

The connexins constitute a family of integral membrane proteins that form channels between adjacent cells. These channels are assembled in plasma membrane domains known as gap junctions and enable cells to directly exchange ions and small molecules. Intercellular communication via gap junctions plays important roles in regulating cell growth and differentiation and in maintaining tissue homeostasis. This type of cell communication is often impaired during cancer development, and several members of the connexin protein family have been shown to act as tumor suppressors. Emerging evidence suggests that the connexin protein family has important roles in colorectal cancer development. In the normal colonic epithelial tissue, three connexin isoforms, connexin 26 (Cx26), Cx32 and Cx43, have been shown to be expressed at the protein level. Colorectal cancer development is associated with loss of connexin expression or relocalization of connexins from the plasma membrane to intracellular compartments. Downregulation of connexins in colorectal carcinomas at the transcriptional level involves cancer-specific promoter hypermethylation. Recent studies suggest that Cx43 may constrain growth of colon cancer cells by interfering with the Wnt/β-catenin pathway. There is also increasing evidence that the connexins may have potential as prognostic markers in colorectal cancer. This review discusses the role of connexins in colorectal cancer pathogenesis, as well as their potential as prognostic markers and targets in the prevention and treatment of the disease.

The influence of desmocollin 1-3 expression on prognosis after curative resection of colorectal liver metastases

PURPOSE

Prognosis after curative resection of colorectal liver metastases is hard to determine based on clinical parameters; biomarkers are therefore needed. The purpose of this study was to determine the value of desmocollins (DSC) as potential biomarkers. Desmocollins are responsible for cell-cell adhesion in epithelial tissue; their loss may lead to reduced cellular adhesion and facilitate cellular migration, enabling tumor cells to form distant metastases. We analyzed DSC expression in colorectal liver metastases with respect to the risk of recurrence following liver resection.

METHODS

Tissue microarrays from 257 consecutive patients who underwent R0-resection of colorectal liver metastases were constructed.

RESULTS

Low expression of DSC 1, 2, and 3 was observed in 55, 54, and 79 % of liver metastases. There was no correlation between site or stage of the primary tumor, presence of extrahepatic tumor, grading, size or number of metastases, and desmocollin expression. Primary tumor stage I or II (p = 0.005) and no or few lymph node metastases (p < 0.001) were associated with a significantly better disease-free survival on univariate analysis. These parameters reached only marginal significance on multivariate analysis (p = 0.059 and p = 0.052, respectively), as did desmocollin 3 expression (p = 0.050). In the subgroup of patients with stages III-IV primary tumors, however, multivariate analysis showed a significant correlation between DSC 3 expression and disease-free survival after liver resection (p = 0.009).

CONCLUSIONS

Reduced expression of DSC3 correlated with an increased risk of developing tumor recurrence after resection of liver metastases. These findings may be helpful in selecting high-risk patients who might benefit from multimodal therapy.

Loss of CD34 and high IGF2 are associated with malignant transformation in solitary fibrous tumors

The aim of this study was to characterize the subgroups of solitary fibrous tumor (SFT) and to investigate the expression of different biomarkers including CD34 and IGF2 in malignant transformation. Two hundred and ninety-four (294) SFTs from a single German consultation center of soft tissue tumors were categorized into the new proposal of SFT designation. We found the fibrous variant in 223 (75.9%), the cellular variant in 65 (22.1%), the fat forming variant in 4 (1.4%), and the giant cell-rich variant in 2 (0.6%) cases. Anatomical location, size, mitotic index, necrosis, cellularity, collagenous ropes, and growth pattern of the vessels were recorded. Criteria of malignancy were found in 68 (23%) tumors. Expression of IGF2, IGF1R, CD34, BCL2, CD99, SMA, S100, PanCK, and Ki67 was analyzed immunohistochemically. Low expression of CD34 and high expression of IGF2 were significantly associated with malignant transformation and the metastatic rate. Moreover the presence of necrosis showed the most significant p-value (p<0.004). Of all SFTs, the fibrous variant is the most common, followed by the cellular variant. The fat-forming and giant cell-rich variants are very rare. Low expression of CD34 and high expression of IGF2 are significantly associated with malignant transformation, and might be an interesting target of individualized therapy.

ADAM and ADAMTS family proteins and their role in the colorectal cancer etiopathogenesis

The ADAM and ADAMTS families, also called adamalysins belong to an important group of extracellular matrix proteins. The ADAMs family belong to both the transmembrane and secreted proteins, while ADAMTS family only contains secreted forms. Adamalysins play an important role in the cell phenotype regulation via their activities in signaling pathways, cell adhesion and migration. The human proteome contains 21 ADAM, and 19 ADAMTS proteins, which are involved in extracellular matrix remodeling, shedding of various substrates such as: adhesion ligands, growth factors, their receptors and diverse cytokines. Recent studies provide evidence that adamalysins play a crucial role in colorectal cancer (CRC) etiopathogenesis. It seems possible that adamalysins might be used as CRC prediction markers or potential pharmaceutical targets. [BMB Reports 2013; 46(3): 139-150]

The prognostic value of the apoptosis pathway in colorectal cancer: a review of the literature on biomarkers identified by immunohistochemistry

Research towards biomarkers that predict patient outcome in colorectal cancer (CRC) is rapidly expanding. However, none of these biomarkers have been recommended by the American Association of Clinical Oncology or the European Group on Tumor Markers. Current staging criteria result in substantial under-and over-treatment of CRC patients. Evasion of apoptosis, a characteristic feature of tumorigenesis, is known to correlate with patient outcome. We reviewed the literature on immunohistochemistry-based studies between 1998 and 2011 describing biomarkers in this pathway in CRC and identified 26 markers. Most frequently described were p53, Bcl-2, survivin, and the Fas and TRAILR1 receptors and their ligands. None of the studies reviewed provided sufficient support for implementing a single marker into current clinical practice. This is likely due to the complex biology of this pathway. We suggest focusing on the combination of key markers within the apoptosis pathway that together represent an ‘apoptotic tumor profile’, which better reflects the status of this pathway in a tumor.

Trilayer micelles for combination delivery of rapamycin and siRNA targeting Y-box binding protein-1 (siYB-1)

A three layer (trilayer) polymeric micelle system based on the self-association of the triblock polymer poly(ethylene glycol)-b-poly{N-[N-(2-aminoethyl)-2-aminoethyl] aspartamide}-b-poly(ε-caprolactone) (PEG-b-PAsp(DET)-b-PCL) has been synthesized and investigated for combination delivery of rapamycin (RAP) and siRNA targeting Y-box binding protein-1 (siYB-1). The trilayer micelle is composed of (a) a hydrophilic poly(ethylene glycol) (PEG) block constituting the outer layer to improve pharmacokinetics, (b) an intermediate compartment composed of the cationic poly{2-[(2-aminoethyl)amino] ethyl aspartamide} (PAsp(DET)) segment for interacting with siYB-1, and (c) an inner hydrophobic poly(ε-caprolactone) (PCL) compartment for encapsulation of RAP. A major advantage of this system is biocompatibility since PEG and PCL are both approved by the FDA, and PAsp(DET) is a non-toxic pH responsive cationic poly(amino acid)-based polymer. In this study, it has been shown that PCL can encapsulate RAP with high loading efficiencies, and PAsp(DET) can successfully interact with siRNA for efficient transfection/knockdown with negligible cytotoxicity. The enhanced therapeutic efficacy of RAP/siYB-1 micelles was demonstrated in cell cultures and in a PC3 xenograft nude mouse model of human prostate cancer. Herein, we demonstrate that trilayer micelles are a promising approach to improve the simultaneous delivery of combination siRNA/drug therapies.

YB-1 synthesis is regulated by mTOR signaling pathway

YB-1 is a eukaryotic protein with numerous intra- and extracellular functions based on its ability to interact with RNA, DNA, and many proteins. In spite of achievements in studying its functions, regulation of YB-1 synthesis in the cell remains poorly understood. In the current study Western and Northern blotting were used to determine the amounts of YB-1 and YB-1 mRNA in rabbit organs and several cell lines. As found, in the majority of studied eukaryotic cells a considerable proportion of YB-1 mRNA was stored in free mRNPs, i.e., was poorly translated. Also, we demonstrated that YB-1 synthesis depended on conditions that determined the rate of cell division. Specific suppression of YB-1 synthesis resulted from inhibition of the mTOR signaling pathway with inhibitor PP242, but not rapamycin. Experiments on reporter constructs showed that dependence of YB-1 mRNA translation on activity of the mTOR signaling pathway was dictated by 5′ untranslated regions of this mRNA, irrelatively of the TOP-like sequences at the beginning of 5′ UTR.

Loss of desmocollin 1-3 and homeobox genes PITX1 and CDX2 are associated with tumor progression and survival in colorectal carcinoma

BACKGROUND

Genomewide expression profiling has identified a number of genes differentially expressed in colorectal carcinomas (CRCs) compared to normal tissue. Some of these genes were linked to epithelial-mesenchymal transition. We tested whether genes including desmocollins and homeobox genes were distinct on the protein level and correlated the expression with clinicopathological data.

METHODS

Tissue microarrays of 402 R0-resected colorectal carcinomas of UICC stage II or III were constructed to evaluate ten biomarkers. Furthermore, mRNA expression of desmocollins was evaluated in eight colon cancer cell lines. Demethylation test was performed by treatment with 5-aza-2´-deoxycytide in five colon cancer cell lines.

RESULTS

On protein level, high expression of desmocollin 1 (DSC1) was observed in 41.6%, DSC2 in 58.0%, DSC3 in 61.4%, E-cadherin in 71.4%, CDX2 in 58.0%, PITX1 in 55.0%, CDK4 in 0.2%, TLE1 in 1.3%, Factor H in 42.5%, and MDM2 in 0.2%. Reduced expression of DSC1-3 was statistically linked to higher grading and DSC2, E-cadherin and CDX2 with shorter survival in high-grade carcinomas. Multivariate analysis showed that pathological stage and low PITX1 expression were statistically associated with shorter patients survival. On mRNA level, seven out of eight cell lines exhibited no expression of DSC1, and four out of seven restored DSC1 expression after demethylation test.

CONCLUSIONS

Reduced expression of PITX1 was independently correlated to shorter patients survival and could serve as a prognostic marker. Decreased expression of DSC1-3 is significantly correlated with higher tumor grading. Downregulation of DSC1 could be explained by DNA hypermethylation in colon cancer cells.

Improving colorectal cancer management: the potential of proteomics

Colorectal cancer (CRC) is the third most common cancer worldwide. Successful treatment is heavily dependent on tumor stage at the time of detection, but unfortunately CRC is often only detected in advanced stages. New biomarkers in the form of genes or proteins that can be used for diagnosis, prognostication, follow-up, and treatment selection and monitoring could be of great benefit for the management of CRC. Furthermore, proteins could prove valuable new targets for therapy. Therefore, clinical proteomics has gained a lot of scientific interest in this regard. To get an overall insight into the extent to which this research has contributed to a better management of CRC, we give a comprehensive overview of the results of proteomics research on CRC, focusing on expression proteomics, in other words, protein profiling studies. Furthermore, we evaluate the potential of the discriminating proteins identified in this research for clinical use as biomarkers for (early) diagnosis, prognosis and follow-up of CRC or as targets for new therapeutic regimens.

Expression of Cyclin D1 Is Associated with β-Catenin Expression and Correlates with Good Prognosis in Colorectal Adenocarcinoma

BACKGROUND

The aim of this study is to investigate the prevalence and prognostic impact of β-catenin and cyclin D1 expression in colorectal carcinoma (CRC) patients.

METHOD

We evaluated immunohistochemial expression of β-catenin and cyclin D1 using 2-mm cores from 220 CRC patients for tissue microarray, and its significance was statistically evaluated.

RESULT

Positive expression of β-catenin and cyclin D1 was found in 72.5% (158 of 218 cases) and 59.4% (129 of 217 cases) of CRC patients, respectively. Expression of β-catenin was significantly correlated with tumor location (P = .017), differentiation (P = .010), lymph node metastasis (P = .032), preoperative carcinoembryonic antigen level (P = .032), and cyclin D1 expression (P = .005). Expression of cyclin D1 was significantly correlated with recurrence and/or metastasis (P = .004). In univariate analysis, β-catenin expression predicted more favorable overall survival (P = .022) and cyclin D1 expression predicted both more favorable overall survival and relapse-free survival (P = .004 and P = .006, respectively). Multivariate analysis showed that tumor stage and expression of cyclin D1 were independent prognostic factors significantly associated with overall survival and relapse-free survival.

CONCLUSION

This study shows that expression of β-catenin and cyclin D1 is associated with favorable clinicopathologic variables and it is a clinically significant prognostic indicator for CRC patients.

Four-protein signature accurately predicts lymph node metastasis and survival in oral squamous cell carcinoma

The presence of lymph node (LN) metastasis significantly affects the survival of patients with oral squamous cell carcinoma (OSCC). Successful detection and removal of positive LNs are crucial in the treatment of this disease. Current evaluation methods still have their limitations in detecting the presence of tumor cells in the LNs, where up to a third of clinically diagnosed metastasis-negative (N0) patients actually have metastasis-positive LNs in the neck. We developed a molecular signature in the primary tumor that could predict LN metastasis in OSCC. A total of 211 cores from 55 individuals were included in the study. Eleven proteins were evaluated using immunohistochemical analysis in a tissue microarray. Of the 11 biomarkers evaluated using receiver operating curve analysis, epidermal growth factor receptor (EGFR), v-erb-b2 erythroblastic leukemia viral oncogene homolog 2 (HER-2/neu), laminin, gamma 2 (LAMC2), and ras homolog family member C (RHOC) were found to be significantly associated with the presence of LN metastasis. Unsupervised hierarchical clustering-demonstrated expression patterns of these 4 proteins could be used to differentiate specimens that have positive LN metastasis from those that are negative for LN metastasis. Collectively, EGFR, HER-2/neu, LAMC2, and RHOC have a specificity of 87.5% and a sensitivity of 70%, with a prognostic accuracy of 83.4% for LN metastasis. We also demonstrated that the LN signature could independently predict disease-specific survival (P = .036). The 4-protein LN signature validated in an independent set of samples strongly suggests that it could reliably distinguish patients with LN metastasis from those who were metastasis-free and therefore could be a prognostic tool for the management of patients with OSCC.

ASPN and GJB2 Are Implicated in the Mechanisms of Invasion of Ductal Breast Carcinomas

The mechanism of progression from ductal carcinoma in situ (DCIS) to invasive ductal carcinoma (IDC) remains largely unknown. We compared gene expression in tumors with simultaneous DCIS and IDC to decipher how diverse proteins participate in the local invasive process.

Twenty frozen tumor specimens with concurrent, but separated, DCIS and IDC were microdissected and evaluated. Total RNA was extracted and microarray analysis was performed using Affymetrix GeneChip® Human Gene 1.0 ST Arrays. Microarray data were validated by quantitative real time reverse transcription-PCR (qRT-PCR) and immunohistochemistry. Controls included seven pure in situ carcinomas, eight fragments from normal breast tissue, and a series of mouse breast carcinomas (MMTV-PyMT).

Fifty-six genes were differentially expressed between DCIS and IDC samples. The genes upregulated in IDC samples, and probably associated with invasion, were related to the epithelial-mesenchymal transition (ASPN, THBS2, FN1, SPARC, and COL11A1), cellular adhesion (GJB2), cell motility and progression (PLAUR, PLAU, BGN, ADAMTS16, and ENPP2), extracellular matrix degradation (MMP11, MMP13, and MMP14), and growth/proliferation (ST6GAL2). qRT-PCR confirmed the expression patterns of ASPN, GJB2, ENPP2, ST6GAL2, and TMBS10. Expression of the ASPN and GJB2 gene products was detected by immunohistochemistry in invasive carcinoma foci. The association of GJB2 protein expression with invasion was confirmed by qRT-PCR in mouse tumors (P < 0.05).

Conclusions: The upregulation of ASPN and GJB2 may play important roles in local invasion of breast ductal carcinomas.

Radiation treatment inhibits monocyte entry into the optic nerve head and prevents neuronal damage in a mouse model of glaucoma

Glaucoma is a common ocular disorder that is a leading cause of blindness worldwide. It is characterized by the dysfunction and loss of retinal ganglion cells (RGCs). Although many studies have implicated various molecules in glaucoma, no mechanism has been shown to be responsible for the earliest detectable damage to RGCs and their axons in the optic nerve. Here, we show that the leukocyte transendothelial migration pathway is activated in the optic nerve head at the earliest stages of disease in an inherited mouse model of glaucoma. This resulted in proinflammatory monocytes entering the optic nerve prior to detectable neuronal damage. A 1-time x-ray treatment prevented monocyte entry and subsequent glaucomatous damage. A single x-ray treatment of an individual eye in young mice provided that eye with long-term protection from glaucoma but had no effect on the contralateral eye. Localized radiation treatment prevented detectable neuronal damage and dysfunction in treated eyes, despite the continued presence of other glaucomatous stresses and signaling pathways. Injection of endothelin-2, a damaging mediator produced by the monocytes, into irradiated eyes, combined with the other glaucomatous stresses, restored neural damage with a topography characteristic of glaucoma. Together, these data support a model of glaucomatous damage involving monocyte entry into the optic nerve.

High KIT and PDGFRA are associated with shorter patients survival in gastroenteropancreatic neuroendocrine tumors, but mutations are a rare event

PURPOSE

(1) To test whether in genomewide expression profiling differentially expressed genes were also distinct on the protein level including KIT and PDGFRA (2) to correlate the expression with clinicopathological parameters (3) to identify activating mutations that might be eligible for tyrosine kinase inhibitor therapy by mutational analysis of tumors with high expression.

METHODS

Gastroenteropancreatic neuroendocrine tumors (GEP NETs) from 119 patients were analyzed for protein expression of ten biomarkers. Mutational analysis of KIT (exon 9, 13, 11 and 17) and PDGFRA (exons 12 and 18) was performed on those samples that showed high protein expression.

RESULTS

High KIT expression was observed in 13% of all specimens, PDGFRA in 33%, CK19 in 26%, CK7 in 2%, CK20 in 5%, S100 in 6%, CD56 in 25%, Chromogranin in 55%, and Synapthophysin in 80%. High expression of KIT and PDGFRA was significantly correlated with shorter disease-specific survival (P = 0.003, P = 0.018, respectively). In multivariate analysis expression of PDGFRA, radicality of surgical treatment and WHO grading influenced disease-specific 10-year survival independently (P = 0.032, P = 0.001 and P = 0.008, respectively). Mutational analysis of highly expressed specimens (n = 51) reveals a novel mutation of KIT in exon 11 (K558N_V559insP) in a well-differentiated metastatic pancreatic neuroendocrine tumor.

CONCLUSIONS

High expression of KIT and PDGFRA was significantly correlated with shorter patients survival and could serve as prognostic marker. Mutations of the KIT gene might open new avenues for tyrosine kinase inhibitor therapy in a subset of patients with advanced pancreatic neuroendocrine tumors.

Tumor suppressor cell adhesion molecule 1 (CADM1) is cleaved by a disintegrin and metalloprotease 10 (ADAM10) and subsequently cleaved by γ-secretase complex

Cell adhesion molecule 1 (CADM1) is a type I transmembrane glycoprotein expressed in various tissues. CADM1 is a cell adhesion molecule with many functions, including roles in tumor suppression, apoptosis, mast cell survival, synapse formation, and spermatogenesis. CADM1 undergoes membrane-proximal cleavage called shedding, but the sheddase and mechanisms of CADM1 proteolysis have not been reported. We determined the cleavage site involved in CADM1 shedding by LC/MS/MS and showed that CADM1 shedding occurred in the membrane fraction and was inhibited by tumor necrosis factor-α protease inhibitor-1 (TAPI-1). An siRNA experiment revealed that ADAM10 mediates endogenous CADM1 shedding. In addition, the membrane-bound fragment generated by shedding was further cleaved by γ-secretase and generated CADM1-intracellular domain (ICD) in a mechanism called regulated intramembrane proteolysis (RIP). These results clarify the detailed mechanism of membrane-proximal cleavage of CADM1, suggesting the possibility of RIP-mediated CADM1 signaling.

Connexin43 acts as a colorectal cancer tumor suppressor and predicts disease outcome

This article is the first to show that loss of connexin43 (Cx43) expression in colorectal tumors is correlated with significantly shorter relapse-free and overall survival. Cx43 was further found to negatively regulate growth of colon cancer cells, in part by enhancing apoptosis. In addition, Cx43 was found to colocalize with β-catenin and reduce Wnt signaling. The study represents the first evidence that Cx43 acts as a colorectal cancer tumor suppressor and that loss of Cx43 expression during colorectal cancer development is associated with reduced patient survival. The study has important implications for the assessment of Cx43 as a prognostic marker and target in colorectal cancer prevention and therapy. Gap junctions consist of intercellular channels that permit direct transfer of ions and small molecules between adjacent cells. The gap junction channel protein Cx43 plays important roles in cell growth control and differentiation and is frequently dysregulated in human cancers. However, the functional importance and clinical relevance of Cx43 in cancer development has remained elusive. Here, we show that Cx43 is downregulated or aberrantly localized in colon cancer cell lines and colorectal carcinomas, which is associated with loss of gap junction intercellular communication. The in situ protein expression of Cx43 was analyzed in colorectal tumors in a cohort of 674 patients and related to established clinicopathological variables and survival. A subgroup of the patients had weak or no expression of Cx43 in tumors. Loss of Cx43 expression was significantly correlated with shorter relapse-free and overall survival. Loss of Cx43 further identified a high-risk subgroup among stage I and stage II patients with reduced relapse-free and overall survival. Ectopic expression of Cx43 in the colon cancer cell line HT29 was associated with reduced growth in monolayer and soft agar cultures and in tumor xenografts. Cx43 was found to colocalize with β-catenin and negatively regulate the Wnt signaling pathway, and expression of Cx43 was associated with increased levels of apoptosis. Altogether, these data indicate that Cx43 is a colorectal cancer tumor suppressor protein that predicts clinical outcome.

Cyclin D1 expression in colorectal cancer is a favorable prognostic factor in men but not in women in a prospective, population-based cohort study

Background

Although colorectal cancer (CRC) is generally not considered to be a hormone-dependent malignancy, several sex-related differences in incidence, molecular characteristics and survival have been reported. Epidemiological studies have consistently shown that increased exposure to female sex hormones is associated with a lower risk of CRC in women, and cyclin D1, an important downstream effector in estrogen-mediated signaling, is commonly activated in CRC. In this study, we analyzed the prognostic significance of cyclin D1 expression in CRC, with particular reference to sex-related differences, in tumors from a large, prospective, population-based cohort.

Methods

Using tissue microarrays and immunohistochemistry, the fraction and intensity of cyclin D1 expression was evaluated in 527 incident CRC cases from the Malmö Diet and Cancer Study. The χ² and Spearman's rho (ρ) tests were used for comparison of cyclin D1 expression and relevant clinicopathological characteristics. Kaplan-Meier analysis and Cox proportional hazards modeling were used to assess the effect of cyclin D1 expression on cancer-specific survival (CSS) in univariate and multivariate analysis, adjusted for established prognostic factors.

Results

Cyclin D1 intensity was significantly lower in male compared with female CRC (P = 0.018). In the full cohort, cyclin D1 expression was associated with a significantly prolonged CSS (hazard ratio (HR) = 0.69; 95% CI 0.49 to 0.96, P = 0.026) but subgroup analysis according to gender revealed a strongly accentuated prognostic effect of cyclin D1 in male CRC (HR = 0.48; 95% CI 0.31 to 0.74, P < 0.001), which was in contrast to female CRC, where cyclin D1 was not prognostic (HR = 1.05; 95% CI 0.62 to 1.78, P = 0.864) (P_interaction = 0.024). The prognostic value of cyclin D1 was not retained in multivariate analysis, either in the full cohort or in male CRC.

Conclusions

Cyclin D1 expression is strongly associated with prolonged survival in male CRC. These findings not only support an important role for cyclin D1 in colorectal carcinogenesis, but also add further weight to the accumulating evidence that CRC is indeed a hormone-dependent malignancy, for which prognostic and treatment-predictive molecular biomarkers should be evaluated differently in women and men.

Interplay between Y-box-binding protein 1 (YB-1) and poly(A) binding protein (PABP) in specific regulation of YB-1 mRNA translation

YB-1 is a DNA- and RNA-binding protein that regulates expression of many important genes. Its deficiency or excess may pose threats, including malignant cellular transformation and metastasis, which explains the necessity of strict control over its amount at every level. As we showed previously, the 3' untranslated region (UTR) of YB-1 mRNA contains a regulatory element specifically binding to YB-1 and PABP (PABPC1). Also, we showed that YB-1 selectively inhibits YB-1 mRNA translation, while PABP stimulates it in a poly(A) tail-independent manner. It was suggested that regulation of YB-1 mRNA translation involves competition between PABP and YB-1 for binding to the regulatory element. Here we offer cogent evidence for this model and add novel details to the mechanism of regulation of YB-1 synthesis. In experiments on regulatory element deletion we showed that it is this element that is responsible for a specific effect of YB-1 and PABP on YB-1 mRNA translation. Mutations eliminating only specific YB-1 affinity for this element suppressed the inhibitory effect of YB-1 and concurrently dramatically decreased the PABP stimulating effect. Mutations reducing only specific PABP affinity for this element, as well as spatial separation of the YB-1- and PABP binding sites, did not affect the YB-1 inhibitory action but completely abolished the positive PABP effect. Together, these results unambiguously prove direct inhibitory action of YB-1 on its mRNA translation, while the positive effect of PABP is realized through displacing YB-1 from the regulatory element.

Constitutive activation of metalloproteinase ADAM10 in mantle cell lymphoma promotes cell growth and activates the TNFα/NFκB pathway

One of the main functions of A Disintegrin and Metalloproteinase 10 (ADAM10) is to regulate the bioavailability of adhesion molecules and ligands to various cellular-signaling receptors. Constitutive activation of ADAM10 has been implicated in the pathogenesis of several types of solid tumors. In this study, we found that mantle cell lymphoma (MCL) cell lines and all 12 patient samples examined expressed the active/mature form of ADAM10. In contrast, PBMCs from healthy donors (n = 5) were negative. Using immunohistochemistry, ADAM10 was readily detectable in 20 of 23 (87%) MCL tumors, but absent in 5 reactive tonsils. Knockdown of ADAM10 using short interfering RNA (siRNA) in MCL cells significantly induced growth inhibition and cell-cycle arrest, and these changes were correlated with down-regulation of cyclin D1, up-regulation of p21(waf1), and significant reductions in the TNFα production/transcriptional activity of NFκBp65. The addition of recombinant ADAM10 to MCL cells led to the opposite biologic effects. Lastly, down-regulation of ADAM10 using siRNA enhanced the growth-suppressing effects mediated by the proteasome inhibitors MG132 and bortezomib. We conclude that constitutive activation of ADAM10 contributes to the growth of MCL and therefore inhibition of ADAM10 may be a useful strategy to enhance the response of MCL to other therapeutic agents.

Molecular clustering identifies complement and endothelin induction as early events in a mouse model of glaucoma

Glaucoma is one of the most common neurodegenerative diseases. Despite this, the earliest stages of this complex disease are still unclear. This study was specifically designed to identify early stages of glaucoma in DBA/2J mice. To do this, we used genome-wide expression profiling of optic nerve head and retina and a series of computational methods. Eyes with no detectable glaucoma by conventional assays were grouped into molecularly defined stages of disease using unbiased hierarchical clustering. These stages represent a temporally ordered sequence of glaucoma states. We then determined networks and biological processes that were altered at these early stages. Early-stage expression changes included upregulation of both the complement cascade and the endothelin system, and so we tested the therapeutic value of separately inhibiting them. Mice with a mutation in complement component 1a (C1qa) were protected from glaucoma. Similarly, inhibition of the endothelin system with bosentan, an endothelin receptor antagonist, was strongly protective against glaucomatous damage. Since endothelin 2 is potently vasoconstrictive and was produced by microglia/macrophages, our data provide what we believe to be a novel link between these cell types and vascular dysfunction in glaucoma. Targeting early molecular events, such as complement and endothelin induction, may provide effective new treatments for human glaucoma.