SciCombinator

Discover the most talked about and latest scientific content & concepts.

Journal: Oncotarget

166

Gastrointestinal stromal tumors (GIST) arise within the interstitial cell of Cajal (ICC) lineage due to activating KIT/PDGFRA mutations. Both ICC and GIST possess primary cilia (PC), which coordinate PDGFRA and Hedgehog signaling, regulators of gastrointestinal mesenchymal development. Therefore, we hypothesized that Hedgehog signaling may be altered in human GIST and controls KIT expression. Quantitative RT-PCR, microarrays, and next generation sequencing were used to describe Hedgehog/PC-related genes in purified human ICC and GIST. Genetic and pharmacologic approaches were employed to investigate the effects of GLI manipulation on KIT expression and GIST cell viability. We report that Hedgehog pathway and PC components are expressed in ICC and GIST and subject to dysregulation during GIST oncogenesis, irrespective of KIT/PDGFRA mutation status. Using genomic profiling, 10.2% of 186 GIST studied had potentially deleterious genomic alterations in 5 Hedgehog-related genes analyzed, including in the PTCH1 tumor suppressor (1.6%). Expression of the predominantly repressive GLI isoform, GLI3, was inversely correlated with KIT mRNA levels in GIST cells and non-KIT/non-PDGFRA mutant GIST. Overexpression of the 83-kDa repressive form of GLI3 or small interfering RNA-mediated knockdown of the activating isoforms GLI1/2 reduced KIT mRNA. Treatment with GLI1/2 inhibitors, including arsenic trioxide, significantly increased GLI3 binding to the KIT promoter, decreased KIT expression, and reduced viability in imatinib-sensitive and imatinib-resistant GIST cells. These data offer new evidence that genes necessary for Hedgehog signaling and PC function in ICC are dysregulated in GIST. Hedgehog signaling activates KIT expression irrespective of mutation status, offering a novel approach to treat imatinib-resistant GIST.

Concepts: DNA, Gene, Genetics, Cell nucleus, Gene expression, Cell, Cancer, Gastrointestinal stromal tumor

156

It is generally accepted that the success of immunotherapy depends on the presence of tumor-specific CD8+ cytotoxic T cells and the modulation of the tumor environment. In this study, we validated mRNA encoding soluble factors as a tool to modulate the tumor microenvironment to potentiate infiltration of tumor-specific T cells. Intratumoral delivery of mRNA encoding a fusion protein consisting of interferon-β and the ectodomain of the transforming growth factor-β receptor II, referred to as Fβ2, showed therapeutic potential. The treatment efficacy was dependent on CD8+ T cells and could be improved through blockade of PD-1/PD-L1 interactions. In vitro studies revealed that administration of Fβ2 to tumor cells resulted in a reduced proliferation and increased expression of MHC I but also PD-L1. Importantly, Fβ2 enhanced the antigen presenting capacity of dendritic cells, whilst reducing the suppressive activity of myeloid-derived suppressor cells. In conclusion, these data suggest that intratumoral delivery of mRNA encoding soluble proteins, such as Fβ2, can modulate the tumor microenvironment, leading to effective antitumor T cell responses, which can be further potentiated through combination therapy.

Concepts: Immune system, DNA, Protein, Cancer, T cell, Major histocompatibility complex, Cytotoxic T cell, MHC class I

154

BRCA1 and BRCA2 are essential for the repair of double-strand DNA breaks, and alterations in these genes are a hallmark of breast and ovarian carcinomas. Other functionally related genes may also play important roles in carcinogenesis. Amplification of EMSY, a putative BRCAness gene, has been suggested to impair DNA damage repair by suppressing BRCA2 function. We employed direct repeat GFP (DR-GFP) and RAD51 foci formation assays to show that EMSY overexpression impairs the repair of damaged DNA, suggesting that EMSY belongs to the family of BRCAness proteins. We also identified a novel phospho-site at threonine 207 (T207) and demonstrated its role in EMSY-driven suppression of DNA damage repair. In vitro kinase assays established that protein kinase A (PKA) directly phosphorylates the T207 phospho-site. Immunoprecipitation experiments suggest that EMSY-driven suppression of DNA damage repair is a BRCA2-independent process. The data also suggest that EMSY amplification is a BRCAness feature, and may help to expand the population of patients who could benefit from targeted therapies that are also effective in BRCA1/2-mutant cancers.

Concepts: DNA, Protein, Gene, Genetics, DNA repair, Protein kinase, BRCA2, BRCA1

153

Immune tolerance to tumor-associated carbohydrate antigens (TACAs) has severely restricted the usefulness of most TACAs. To overcome this problem, we selected a sialylated trisaccharide TACA, GM3, as a target antigen, and tested a new immunotherapeutic strategy by combining metabolic bioengineering with dendritic cell (DC) vaccination. We engineered cancer cells to express an artificial structure, N-phenylacetyl-D-neuraminic acid, in place of the natural N-acetyl-D-neuraminic acid of GM3 by using N-phenylacetyl-D-mannosamine (ManNPhAc) as a biosynthetic precursor. Next, we selectively targeted the bioengineered cancer cells by vaccination with DCs pulsed with the GM3 N-phenylacetyl derivative. Vaccination with GM3NPhAc-KLH-loaded DCs elicited robust GM3NPhAc-specific T cell-dependent immunity. The results showed that this strategy could significantly inhibit FBL3 tumor growth and prolong the survival of tumor-bearing mice; B16F10 lung metastases could also be reduced. These findings lay out a new strategy for overcoming immune tolerance to TACAs, such as GM3, for the development of effective tumor immunotherapies.

Concepts: Immune system, Antibody, Protein, Cancer, Oncology, Lung cancer, Immunology, Immunotherapy

146

Asbestos is a harmful and exceptionally persistent natural material. Malignant mesothelioma (MM), an asbestos-related disease, is an insidious, lethal cancer that is poorly responsive to current treatments. Minimally invasive, specific, and sensitive biomarkers providing early and effective diagnosis in high-risk patients are urgently needed. MicroRNAs (miRNAs, miRs) are endogenous, non-coding, small RNAs with established diagnostic value in cancer and pollution exposure. A systematic review and a qualitative meta-analysis were conducted to identify high-confidence miRNAs that can serve as biomarkers of asbestos exposure and MM.

Concepts: Cancer, Oncology, Medical terms, MicroRNA, Mesothelioma, Asbestos, Asbestos and the law, Wittenoom, Western Australia

146

The relationship between age, vitamin D status, expression and functionality of the vitamin D receptor (VDR), and key genes in the vitamin D pathway in immune cells is unclear. We enrolled adults 50 to 69 years old (20 subjects) and 70+ (20 subjects) and measured: 1) 25(OH)D levels by liquid chromatography/mass spectrometry; and 2) mRNA expression of VDR, 1α-OHase, 1,25D3-MARRS, TREM-1, cathelicidin, RIG-I, and interferon-β by qRT-PCR. Mean serum 25(OH)D was 30 ± 4 ng/mL and was not associated with age. Baseline expression of VDR, 1α-OHase, 1,25D3-MARRS, TREM-1, and RIG-I also did not differ by age; IFN-β expression, however, was higher in the 70+ year old group. 25(OH)D3- and 1,25(OH)2D3-induced VDR, TREM-1 and cathelicidin expression were similar between age groups, as was LPS-induced expression of VDR and of 1α-OHase. Ligand-induced 1,25D3-MARRS expression was higher in subjects ≥ 70 years. Serum 25(OH)D was inversely associated with LPS-stimulated VDR expression and with baseline or vitamin D-induced TREM-1 expression, adjusting for age, self-rated health, and functional status. In healthy adults ≥ 50 years, the expression and functionality of the VDR, 1α-OHase and key vitamin D pathway genes were not consistently associated with age.

Concepts: Immune system, DNA, Protein, Vitamin D, Genetics, Gene expression, Blood, PBMC

146

Breast cancer is very common and highly fatal in women. Current non-invasive detection methods like mammograms are unsatisfactory. Lipidomics, a promising detection method, may serve as a novel prognostic approach for breast cancer in high-risk patients.

Concepts: Cancer, Breast cancer, Metastasis, Estrogen, Pleural effusion, Breast, Mammography

145

In recent years, most studies on breast cancer relapse and metastasis have focused on non-luminal breast cancers (including the basal-like and HER-2 subtypes) because of their poor prognosis. However, the luminal B subtype is more common, but this type has not been investigated as thoroughly. In the current study, we collected data on 258 patients with luminal-B breast cancer patients with recurrence and metastasis served as the observation group, and 189 patients with non-luminal breast cancer during the same period served as the control group. This study aimed to investigate the pattern of recurrence and clinical outcome after follow-up treatment for luminal B breast cancer. We found a higher proportion of local recurrence and single bone metastasis in patients with luminal B breast cancer than in patients in the non-luminal groups. The risk of recurrence and metastasis in patients with luminal B breast cancer during a 2- to 5-year period and after 5 years was still present, but the risk in patients with non-luminal breast cancers had obviously decreased during the same period. Patients with luminal B breast cancer with recurrence or/and metastasis had a better prognosis after reasonable treatment. The recurrence patterns and clinical outcomes of patients with luminal B breast cancer according to HER2 status were also different, to some degree. These results are of potential clinical relevance especially for the monitoring of clinical prognosis and targeted therapy intervention for luminal B breast cancer.

Concepts: Cancer, Breast cancer, Metastasis, Oncology, Lung cancer, Chemotherapy, HER2/neu

142

In cancer, upregulated Ras promotes cellular transformation and proliferation in part through activation of oncogenic Ras-MAPK signaling. While directly inhibiting Ras has proven challenging, new insights into Ras regulation through protein-protein interactions may offer unique opportunities for therapeutic intervention. Here we report the identification and validation of Aurora kinase A (Aurora A) as a novel Ras binding protein. We demonstrate that the kinase domain of Aurora A mediates the interaction with the N-terminal domain of H-Ras. Further more, the interaction of Aurora A and H-Ras exists in a protein complex with Raf-1. We show that binding of H-Ras to Raf-1 and subsequent MAPK signaling is enhanced by Aurora A, and requires active H-Ras. Thus, the functional linkage between Aurora A and the H-Ras/Raf-1 protein complex may provide a mechanism for Aurora A’s oncogenic activity through direct activation of the Ras/MAPK pathway.

Concepts: Protein, Protein structure, Signal transduction, MAPK/ERK pathway, Aurora kinase, Aurora A kinase, C-terminus, N-terminus

142

We assess the efficacy and safety of canaloplasty and trabeculectomy for treatment of glaucoma. We searched the China National Knowledge Infrastructure, PubMed, Web of Science, and WanFang databases for potentially eligible studies. Pooled risk ratio (RR) with 95% confidence interval (CI) was calculated using random- or fixed-effect models if appropriate. Eight studies were included for meta-analysis. There was no difference in intraocular pressure at 6 months (WMD = 0.97, 95%CI: -0.48-2.41). Intraocular pressure in canaloplasty group 12 months after operation was higher than in trabeculectomy group (WMD = 1.90, 95%CI: 0.12-3.69), P < 0.05). The canaloplasty group showed higher success rate than trabeculectomy group (RR = 0.86, 95%CI: 0.77-0.97). The canaloplasty group was more likely to have hyphema (RR = 2.96, 95%CI: 1.51-5.83), P < 0.05) than trabeculectomy group (RR = 0.24, 95, CI(0.06-0.89), P < 0.05]. The incidence of and hypotony and postoperative choroid abnormalities in canaloplasty group was significantly lower than that in trabeculectomy group (RR = 0.30, 95%CI: 0.11-0.83; RR = 0.24, 95%CI: 0.09-0.66), P < 0.05). Both trabeculectomy and canaloplasty can significantly reduce the intraocular pressure in glaucoma patients at 12 months after operation, trabeculectomy leads a more marked IOP decrease than canaloplasty at the cost of a higher complication rate and more demanding for postoperative care.

Concepts: Medical statistics, Intraocular pressure, Glaucoma, Ophthalmology, Confidence interval, Trabecular meshwork, Trabeculectomy