Oncogenic non-V600 mutations evade the regulatory machinery of RAF including the Cdc37/Hsp90 chaperone and the 14-3-3 scaffold.

The Ser/Thr kinase RAF, particularly BRAF isoform is a dominant target of oncogenic mutations and many mutations have been identified in various cancers. However, how these mutations except V600E evade the regulatory machinery of RAF protein and hence trigger its oncogenicity remains unclear. In this study, we used mutagenesis, peptide affinity assay, immunoprecipitation, immunoblot, and complementary split luciferase assay as well as mouse xenograft tumour model to investigate how the function of RAF is cooperatively regulated by Cdc37/Hsp90 chaperones and 14-3-3 scaffolds and how this regulatory machinery is evaded by prevalent non-V600 mutations.

BRAF(V600E) mutation together with loss of Trp53 or pTEN drives the origination of hairy cell leukemia from B-lymphocytes.

Hairy cell leukemia (HCL) is a B-lymphoma induced by BRAF(V600E) mutation. However, introducing BRAF(V600E) in B-lymphocytes fails to induce hematological malignancy, suggesting that BRAF(V600E) needs concurrent mutations to drive HCL ontogeny. To resolve this issue, here we surveyed human HCL genomic sequencing data.

Application of phage display for T-cell receptor discovery.

The immune system is tasked to keep our body unharmed and healthy. In the immune system, B- and T-lymphocytes are the two main components working together to stop and eliminate invading threats like virus particles, bacteria, fungi and parasite from attacking our healthy cells. The function of antibodies is relatively more direct in target recognition as compared to T-cell receptors (TCR) which recognizes antigenic peptides being presented on the major histocompatibility complex (MHC).

The stability of R-spine defines RAF inhibitor resistance: A comprehensive analysis of oncogenic BRAF mutants with in-frame insertion of αC-β4 loop.

Although targeting BRAF mutants with RAF inhibitors has achieved promising outcomes in cancer therapy, drug resistance remains a remarkable challenge, and underlying molecular mechanisms are not fully understood. Here, we characterized a previously unknown group of oncogenic BRAF mutants with in-frame insertions (LLR or VLR) of αC-β4 loop. Using structure modeling and molecular dynamics simulation, we found that these insertions formed a large hydrophobic network that stabilizes R-spine and thus triggers the catalytic activity of BRAF.

IL13RA2 Is Differentially Regulated in Papillary Thyroid Carcinoma vs Follicular Thyroid Carcinoma.

Context: The interleukin-13 receptor alpha2 (IL13RA2), which is known to be overexpressed in glioblastoma multiforme, plays a role in various cellular processes such as cell migration that may contribute to tumor progression. Studies have attributed IL13RA2 to invasion and metastasis in cancers of the ovary, breast, and pancreas, but the pathological role of IL13RA2 in thyroid cancer is still unclear.

Objective: This study aims to evaluate IL13RA2 expression in thyroid carcinomas and to examine the role of IL13RA2 in the progression of papillary thyroid carcinoma (PTC).

Intra-patient and inter-patient comparisons of DNA damage response biomarkers in Nasopharynx Cancer (NPC): analysis of NCC0901 randomised controlled trial of induction chemotherapy in locally advanced NPC.

Background: Inter-patient heterogeneity in radiation-induced DNA damage responses is proposed to reflect intrinsic variations in tumour and normal tissue radiation sensitivity, but the prediction of phenotype by a molecular biomarker is influenced by clinical confounders and assay reproducibility. Here, we characterised the intrapatient and inter-patient heterogeneity in biomarkers of DNA damage and repair and radiation-induced apoptosis.

Methods: We enrolled 85 of 172 patients with locally advanced nasopharynx cancer from a randomised controlled phase II/III trial of induction chemotherapy added to chemo-radiotherapy.

Ultrafast Single-Cell Level Enzymatic Tumor Profiling.

In the context of tumor analysis, the implementation of precision medicine requires on-time clinical measurements, which requires rapid large-scale single-cell screening that obtains cell population distributions and functions in tumors to determine disease progression for therapeutics. In this study, a high-throughput screening (HTS) platform integrating optical fluorescence detectors and a computational method was developed as a droplet-based microfluidic flow cytometer (Droplet-μFC) to comprehensively analyze multiple proteolytic activities of a patient-derived tumor (with ∼0.5-2 M cells) at single-cell resolution within 2 h.

The dimer-dependent catalytic activity of RAF family kinases is revealed through characterizing their oncogenic mutants.

Although extensively studied for three decades, the molecular mechanisms that regulate the RAF/MEK/ERK kinase cascade remain ambiguous. Recent studies identified the dimerization of RAF as a key event in the activation of this cascade. Here, we show that in-frame deletions in the β3-αC loop activate ARAF as well as BRAF and other oncogenic kinases by enforcing homodimerization.

Matrix metalloproteinase-1 facilitates MSC migration via cleavage of IGF-2/IGFBP2 complex.

The specific mechanism underlying the tumor tropism of human mesenchymal stem cells (MSCs) for cancer is not well defined. We previously showed that the migration potential of MSCs correlated with the expression and protease activity of matrix metalloproteinase (MMP)-1. Furthermore, highly tumor-tropic MSCs expressed higher levels of MMP-1 and insulin-like growth factor (IGF)-2 than poorly migrating MSCs.

Interleukin-13 receptor alpha 2 cooperates with EGFRvIII signaling to promote glioblastoma multiforme.

The interleukin-13 receptor alpha2 (IL-13Rα2) is a cancer-associated receptor overexpressed in human glioblastoma multiforme (GBM). This receptor is undetectable in normal brain which makes it a highly suitable target for diagnostic and therapeutic purposes. However, the pathological role of this receptor in GBM remains to be established.

Exploiting molecular genomics in precision radiation oncology: a marriage of biological and physical precision.

Achieving local tumour control is paramount for cure in head and neck and prostate cancers. With the transition to precision radiotherapy (RT) techniques, survival rates have improved in the majority of these cancers, but a substantial proportion of 30-40% still relapse following primary treatment. Recent large-scale molecular profiling studies have revealed unique biological events that could explain for tumour aggression and resistance to therapies, redefining the molecular taxonomy of head and neck and prostate cancers.

Human mesenchymal stem cells preferentially migrate toward highly oncogenic human hepatocellular carcinoma cells with activated EpCAM signaling.

The epithelial cell adhesion molecule (EpCAM) is a type I transmembrane glycoprotein that is regarded as one of the markers for tumor initiating cells (TIC) in human hepatocellular carcinoma (HCC). Much work has been directed towards targeting these TICs as a mean of placing these master regulators of cell proliferation and drug resistance under control. Human bone marrow-derived mesenchymal stem cells are known to exhibit an innate property of tumor tropism.

Recent discoveries concerning the tumor - mesenchymal stem cell interactions.

Tumor microenvironment plays a crucial role in coordination with cancer cells in the establishment, growth and dissemination of the tumor. Among cells of the microenvironment, mesenchymal stem cells (MSCs) and their ability to evolve into cancer associated fibroblasts (CAFs) have recently generated a major interest in the field. Numerous studies have described the potential pro- or anti-tumorigenic action of MSCs.

Soluble Factors from Human Fetal Bone Marrow-Derived Mesenchymal Stem Cells: Preparation of Conditioned Medium and Its Effect on Tumor Cells.

Mesenchymal stem cells (MSCs) possess some unique features (inherent tumor tropism, anti-inflammatory and immunosuppressive properties) that are not commonly found in conventional anti-cancer agents. These cells are known to secrete a vast array of proteins including growth factors, cytokines, chemokines, extracellular matrix metalloproteinases, and their corresponding inhibitors which exhibit profound effects on the microenvironment. However, the lack of a uniform method for culturing MSCs and their paracrine factors has hindered our understanding of MSC biology.

Redox-Active Mn Porphyrin-based Potent SOD Mimic, MnTnBuOE-2-PyP(5+), Enhances Carbenoxolone-Mediated TRAIL-Induced Apoptosis in Glioblastoma Multiforme.

Glioblastoma multiforme is the most malignant tumor of the brain and is challenging to treat due to its highly invasive nature and heterogeneity. Malignant brain tumor displays high metabolic activity which perturbs its redox environment and in turn translates to high oxidative stress. Thus, pushing the oxidative stress level to achieve the maximum tolerable threshold that induces cell death is a potential strategy for cancer therapy.

Isolating dividing neural and brain tumour cells for gene expression profiling.

Background: The characterisation of dividing brain cells is fundamental for studies ranging from developmental and stem cell biology, to brain cancers. Whilst there is extensive anatomical data on these dividing cells, limited gene transcription data is available due to technical constraints.

New Method: We focally isolated dividing cells whilst conserving RNA, from culture, primary neural tissue and xenografted glioma tumours, using a thymidine analogue that enables gene transcription analysis.

Transcriptional profiling of dividing tumor cells detects intratumor heterogeneity linked to cell proliferation in a brain tumor model.

Intratumor heterogeneity is a primary feature of high-grade gliomas, complicating their therapy. As accumulating evidence suggests that intratumor heterogeneity is a consequence of cellular subsets with different cycling frequencies, we developed a method for transcriptional profiling of gliomas, using a novel technique to dissect the tumors into two fundamental cellular subsets, namely, the proliferating and non-proliferating cell fractions. The tumor fractions were sorted whilst maintaining their molecular integrity, by incorporating the thymidine analog 5-ethynyl-2'-deoxyuridine into actively dividing cells.

Combined treatment of Nimotuzumab and rapamycin is effective against temozolomide-resistant human gliomas regardless of the EGFR mutation status.

Background: The treatment of glioblastoma multiforme (GBM) is an unmet clinical need. The 5-year survival rate of patients with GBM is less than 3%. Temozolomide (TMZ) remains the standard first-line treatment regimen for gliomas despite the fact that more than 90% of recurrent gliomas do not respond to TMZ after repeated exposure.

Paracrine factors of human fetal MSCs inhibit liver cancer growth through reduced activation of IGF-1R/PI3K/Akt signaling.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related death in the world. The multikinase inhibitor sorafenib only demonstrated marginal improvement in overall survival for advanced disease prompted the search for alternative treatment options. Human mesenchymal stem cells (MSCs) have the ability to home to tumor cells.

Matrix metalloproteinase-1-mediated mesenchymal stem cell tumor tropism is dependent on crosstalk with stromal derived growth factor 1/C-X-C chemokine receptor 4 axis.

Human bone marrow-derived mesenchymal stem cells (MSCs) have the unique ability to home toward injuries or tumor sites. We have previously shown that the tumor-tropic property is dependent on the intrinsic expression and activity of the matrix remodeling gene, matrix metalloproteinase 1 (MMP-1). Herein, crosstalk between MMP-1/protease activated receptor 1 (PAR-1) and the G-protein coupled receptor stromal-derived growth factor 1 (SDF-1)/C-X-C chemokine receptor 4 (CXCR-4) in facilitating cell migration was investigated.

Biological effects of cancer-secreted factors on human mesenchymal stem cells.

Mesenchymal stem cells or mesenchymal stromal cells (MSCs) have been considered as a carrier of therapeutic gene because of their inherent ability to migrate to the tumors, and yet there are controversial reports suggesting the tumor-promoting and tumor-inhibiting effects of MSCs. Al-Toub and colleagues provide further insights into the cellular interactions between MSCs and tumors and demonstrate that conditioned media derived from different cancer cells could influence MSC phenotype and gene expression. These changes in MSCs may be modulated by the tumor-derived interleukin-1 beta (IL-1β) and transforming growth factor-beta (TGF-β) signaling.

Signaling molecules and pathways involved in MSC tumor tropism.

Human bone marrow is a reservoir containing cells with different self-renewal capabilities, such as mesenchymal stem cells (MSC) and hematopoeitic stem cells (HSC). MSC in particular have been increasingly used in preclinical and clinical treatment of tissue regenerative disorder. Understanding the molecular mechanisms underlying MSC homing and mobilization is critical to the design of rational cell therapy approaches.

Preclinical evaluation of transcriptional targeting strategy for human hepatocellular carcinoma in an orthotopic xenograft mouse model.

Gene regulation of many key cell-cycle players in S-, G(2) phase, and mitosis results from transcriptional repression in their respective promoter regions during the G(0) and G(1) phases of cell cycle. Within these promoter regions are phylogenetically conserved sequences known as the cell-cycle-dependent element (CDE) and cell-cycle genes homology regions (CHR) sites. Thus, we hypothesize that transcriptional regulation of cell-cycle regulation via the CDE/CHR region together with liver-specific apolipoprotein E (apoE)-hAAT promoter could bring about a selective transgene expression in proliferating human hepatocellular carcinoma.

Carbenoxolone enhances TRAIL-induced apoptosis through the upregulation of death receptor 5 and inhibition of gap junction intercellular communication in human glioma.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been used extensively in cancer therapy. However, more than half of glioblastoma multiforme are insensitive to the apoptotic effect of TRAIL. Improvement in therapeutic modalities that enhances the efficacy of TRAIL in glioma is much sought after.

Human bone marrow-derived mesenchymal stem cells suppress human glioma growth through inhibition of angiogenesis.

Tumor tropism of human bone marrow-derived mesenchymal stem cells (MSC) has been exploited for the delivery of therapeutic genes for anticancer therapy. However, the exact contribution of these cells in the tumor microenvironment remains unknown. In this study, we examined the biological effect of MSC on tumor cells.