Tissue factor is a critical regulator of radiation therapy-induced glioblastoma remodeling.

Radiation therapy (RT) provides therapeutic benefits for patients with glioblastoma (GBM), but inevitably induces poorly understood global changes in GBM and its microenvironment (TME) that promote radio-resistance and recurrence. Through a cell surface marker screen, we identified that CD142 (tissue factor or F3) is robustly induced in the senescence-associated ß-galactosidase (SA-ßGal)-positive GBM cells after irradiation. F3 promotes clonal expansion of irradiated SA-ßGal+ GBM cells and orchestrates oncogenic TME remodeling by activating both tumor-autonomous signaling and extrinsic coagulation pathways. Intratumoral F3 signaling induces a mesenchymal-like cell state transition and elevated chemokine secretion. Simultaneously, F3-mediated focal hypercoagulation states lead to activation of tumor-associated macrophages (TAMs) and extracellular matrix (ECM) remodeling. A newly developed F3-targeting agent potently inhibits the aforementioned oncogenic events and impedes tumor relapse in vivo. These findings support F3 as a critical regulator for therapeutic resistance and oncogenic senescence in GBM, opening potential therapeutic avenues.

Emodin coupled with high LET neutron beam-a novel approach to treat on glioblastoma.

The primary motivation of this investigative study is trying to find an alternative treatment that can be used to slow down or treat glioblastoma due to the witnessed toxic side effects of the current drugs coupled with limited effectiveness in overall treatment. Consequently, a Chinese plant extract emodin proves to play a critical role in this investigative study since results from the Western blot and the other accompanying assays for anti-cancer effects indicate that it cannot work a lot to suppress cell migration and possible invasion, but rather emodin can be combined with radiation to give desired outcomes. Our result shows that the kind of radiation which acts well with emodin is neutron radiation rather than gamma radiation. Emodin significantly enhanced the radiosensitivity of LN18 and LN428 cells to γ-rays through MTT assay and cell counting. Accordingly, exposure to neutron radiation in the presence of emodin induced apoptotic cell death and autophagic cell death to a significantly higher extent, and suppressed cell migration and invasiveness more robustly. These effects are presumably due to the ability of emodin to amplify the effective dose from neutron radiation more efficiently. Thus, the study below is one such trial towards new interventional discovery and development in relation to glioblastoma treatment.

Effects of gold nanoparticles on normal hepatocytes in radiation therapy.

Background: Gold nanoparticles (GNP, AuNPs) have received much attention as a tool to improve the therapeutic index of radiation therapy. This study aimed to evaluate the normal in vitro toxicity of AuNPs at kilovoltage energies on hepatocytes to provide scientific support for using AuNPs with radiotherapy. Methods: Using the same treatment protocol applied to tumor cell lines, hepatocytes were exposed to AuNPs and/or radiation at various time points. Results: The combination of X-ray irradiation and AuNPs did not have any significant effect on cell survival and apoptosis in normal hepatocytes. Furthermore, the combination treatment resulted in no or little change in the level of gamma-H2A histone family member X (γ-H2AX), a marker for DNA double-strand breaks (DSB), nor on the proportion of cells in the G2/M phase. Additionally, interleukin-8 (IL-8) secretion was measured using an enzyme-linked immunosorbent assay (ELISA) to assess its role in tumor progression and angiogenesis. The combination of irradiation and AuNP treatment revealed no significant reduction in hepatocyte viability, proliferation, or secretory capacity compared to cells receiving either treatment alone. According to this study, AuNPs in combination with radiation do have potentially in the treatment of hepatocellular carcinoma (HCC) with no critical cytotoxicity on normal tissue. Conclusions: Therefore, it is postulated that radiation and AuNPs are an effective combination therapy against HCC with no little cytotoxic effects on normal tissue, a hypothesis which warrants further investigation in in vivo, as well as in in vitro.

Aripiprazole sensitizes head and neck cancer cells to ionizing radiation by enhancing the production of reactive oxygen species.

Drug repositioning is an alternative process for drug development in cancer. Specifically, it is a strategy for the discovery of new antitumor drugs by screening previously approved clinical drugs. On the basis of this strategy, aripiprazole, an antipsychotic drug, was found to have anticancer activity. In this study, we investigated the radiosensitizing effects of aripiprazole on head and neck cancer cells at sublethal doses of ionizing radiation (IR) in vitro and in vivo. Treatment with aripiprazole suppressed the growth of head and neck cancer cells in a concentration-dependent manner, as evidenced by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Intriguingly, aripiprazole significantly enhanced the sensitivity of these cells to the IC50 dose of IR. The combination of aripiprazole with IR synergistically increased annexin and propidium iodide double-positive and terminal deoxynucleotidyl transferase dUTP nick end labeling-positive cell populations, and induced cleaved poly(ADP-ribose) polymerase and caspase-3 expression, indicating the induction of apoptosis in these cells. Aripiprazole and IR-induced apoptosis were accompanied by an increase in reactive oxygen species and was almost completely suppressed by the addition of the antioxidant, N-acetylcysteine. Finally, aripiprazole greatly sensitized xenograft tumors to IR at doses that did not affect tumor growth. Taken together, these results suggest that aripiprazole could be considered a potent radiosensitizer for head and neck cancer.

Interaction of curcumin with glioblastoma cells via high and low linear energy transfer radiation therapy inducing radiosensitization effects.

Glioblastoma is a deadly cancer tumor in the brain and has a survival rate of about 15 months. Despite the high mortality rate, temozolomide has proven to increase the survival rate of patients when combined with radiotherapy. However, its effects may be limited because some patients develop therapeutic resistance. Curcumin has proven to be a cancer treatment due to its broad anticancer spectrum, high efficiency and low toxic level. Additionally, curcumin significantly enhanced radiation efficacy under high and low Linear Energy Transfer (LET) radiation conditions in vitro. In combination with radiation, curcumin increased the cell population in the sub-G1 phase and the reactive oxygen species (ROS) level, ultimately increasing GBM cellular apoptosis. The radiosensitizing effects of curcumin are much higher in neutron (high LET)-irradiated cell lines than in γ (low LET)-irradiated cell lines. Curcumin plus neutron combination significantly inhibited cell invasion compared with that of single treatment or curcumin combined γ-ray treatment. Curcumin enhances the radiosensitivity of Glioblastoma (GBM), suggesting it may have clinical utility in combination cancer treatment with neutron high-LET radiation.

CXCR4 uses STAT3-mediated slug expression to maintain radioresistance of non-small cell lung cancer cells: emerges as a potential prognostic biomarker for lung cancer.

Lung cancer is one of the most common reasons for cancer-induced mortality across the globe, despite major advancements in the treatment strategies including radiotherapy and chemotherapy. Existing reports suggest that CXCR4 is frequently expressed by malignant tumor and is imperative for vascularization, tumor growth, cell migration, and metastasis pertaining to poor prognosis. In this study, we infer that CXCR4 confers resistance to ionizing radiation (IR) in nonsmall cell lung cancer (NSCLC) cells. Further, on the basis of colony forming ability, one finds that drug-resistant A549/GR cells with improved CXCR4 expression exhibited more resistance to IR than A549 cells evidenced along with a reduction in the formation of γ-H2AX foci after IR. Transfection of shRNA against CXCR4 or treatment of pharmacological inhibitor (AMD3100) both led to sensitization of A549/GR cells towards IR. Conversely, the overexpression of CXCR4 in A549 and H460 cell lines was found to improve clonogenic survival, and reduce the formation of γ-H2AX foci after IR. CXCR4 expression was further correlated with STAT3 activation, and suppression of STAT3 activity with siSTAT3 or a specific inhibitor (WP1066) significantly stymied the colony-forming ability and increased γ-H2AX foci formation in A549/GR cells, indicating that CXCR4-mediated STAT3 signaling plays an important role for IR resistance in NSCLC cells. Finally, CXCR4/STAT3 signaling was mediated with the upregulation of Slug and downregulation of the same with siRNA, which heightened IR sensitivity in NSCLC cells. Our data collectively suggests that CXCR4/STAT3/Slug axis is paramount for IR resistance of NSCLC cells, and can be regarded as a therapeutic target to enhance the IR sensitivity of this devastating cancer.

ANO1 regulates the maintenance of stemness in glioblastoma stem cells by stabilizing EGFRvIII.

Glioblastoma multiforme (GBM) or glioblastoma is the most deadly malignant brain tumor in adults. GBM is difficult to treat mainly due to the presence of glioblastoma stem cells (GSCs). Epidermal growth factor receptor variant III (EGFRvIII) has been linked to stemness and malignancy of GSCs; however, the regulatory mechanism of EGFRvIII is largely unknown. Here, we demonstrated that Anoctamin-1 (ANO1), a Ca2+-activated Cl- channel, interacts with EGFRvIII, increases its protein stability, and supports the maintenance of stemness and tumor progression in GSCs. Specifically, shRNA-mediated knockdown and pharmacological inhibition of ANO1 suppressed the self-renewal, invasion activities, and expression of EGFRvIII and related stem cell factors, including NOTCH1, nestin, and SOX2 in GSCs. Conversely, ANO1 overexpression enhanced the above phenomena. Mechanistically, ANO1 protected EGFRvIII from proteasomal degradation by directly binding to it. ANO1 knockdown significantly increased survival in mice and strongly suppressed local invasion of GSCs in an in vivo intracranial mouse model. Collectively, these results suggest that ANO1 plays a crucial role in the maintenance of stemness and invasiveness of GSCs by regulating the expression of EGFRvIII and related signaling molecules, and can be considered a promising therapeutic target for GBM treatment.

PARK7 maintains the stemness of glioblastoma stem cells by stabilizing epidermal growth factor receptor variant III.

PARK7 is involved in many key cellular processes, including cell proliferation, transcriptional regulation, cellular differentiation, oxidative stress protection, and mitochondrial function maintenance. Deregulation of PARK7 has been implicated in the pathogenesis of various human diseases, including cancer. Here, we aimed to clarify the effect of PARK7 on stemness and radioresistance of glioblastoma stem cells (GSCs). Serum differentiation and magnetic cell sorting of GSCs revealed that PARK7 was preferentially expressed in GSCs rather than differentiated GSCs. Immunohistochemical staining showed enhanced expression of PARK7 in glioma tissues compared to that in normal brain tissues. shRNA-mediated knockdown of PARK7 inhibited the self-renewal activity of GSCs in vitro, as evidenced by the results of neurosphere formation, limiting dilution, and soft-agar clonogenic assays. In addition, PARK7 knockdown suppressed GSC invasion and enhanced GSC sensitivity to ionizing radiation (IR). PARK7 knockdown suppressed expression of GSC signatures including nestin, epidermal growth factor receptor variant III (EGFRvIII), SOX2, NOTCH1, and OCT4. Contrarily, overexpression of PARK7 in CD133- non-GSCs increased self-renewal activities, migration, and IR resistance, and rescued the reduction of GSC factors under shPARK7-transfected and serum-differentiation conditions. Intriguingly, PARK7 acted as a co-chaperone of HSP90 by binding to it, protecting EGFRvIII from proteasomal degradation. Knockdown of PARK7 increased the production of reactive oxygen species, inducing partial apoptosis and enhancing IR sensitivity in GSCs. Finally, PARK7 knockdown increased mouse survival and IR sensitivity in vivo. Based on these data, we propose that PARK7 plays a pivotal role in the maintenance of stemness and therapeutic resistance in GSCs.

Peroxisome proliferator-activated receptor gamma as a theragnostic target for mesenchymal-type glioblastoma patients.

Glioblastomas (GBMs) are characterized by four subtypes, proneural (PN), neural, classical, and mesenchymal (MES) GBMs, and they all have distinct activated signaling pathways. Among the subtypes, PN and MES GBMs show mutually exclusive genetic signatures, and the MES phenotype is, in general, believed to be associated with more aggressive features of GBM: tumor recurrence and drug resistance. Therefore, targeting MES GBMs would improve the overall prognosis of patients with fatal tumors. In this study, we propose peroxisome proliferator-activated receptor gamma (PPARγ) as a potential diagnostic and prognostic biomarker as well as therapeutic target for MES GBM; we used multiple approaches to assess PPARγ, including biostatistics analysis and assessment of preclinical studies. First, we found that PPARγ was exclusively expressed in MES glioblastoma stem cells (GSCs), and ligand activation of endogenous PPARγ suppressed cell growth and stemness in MES GSCs. Further in vivo studies involving orthotopic and heterotopic xenograft mouse models confirmed the therapeutic efficacy of targeting PPARγ; compared to control mice, those that received ligand treatment exhibited longer survival as well as decreased tumor burden. Mechanistically, PPARγ activation suppressed proneural-mesenchymal transition (PMT) by inhibiting the STAT3 signaling pathway. Biostatistical analysis using The Cancer Genomics Atlas (TCGA, n = 206) and REMBRANDT (n = 329) revealed that PPARγ upregulation is linked to poor overall survival and disease-free survival of GBM patients. Analysis was performed on prospective (n = 2) and retrospective (n = 6) GBM patient tissues, and we finally confirmed that PPARγ expression was distinctly upregulated in MES GBM. Collectively, this study provides insight into PPARγ as a potential therapeutic target for patients with MES GBM.