Repurposing synthetic and natural derivatives induces apoptosis in an orthotopic glioma-induced xenograft model by modulating WNT/β-catenin signaling

BACKGROUND

Glioblastomas arise from multistep tumorigenesis of the glial cells. Despite the current state-of-art treatment, tumor recurrence is inevitable. Among the innovations blooming up against glioblastoma, drug repurposing could provide profound premises for treatment enhancement. While considering this strategy, the efficacy of the repurposed drugs as monotherapies were not up to par; hence, the focus has now shifted to investigate the multidrug combinations.

AIM

To investigate the efficacy of a quadruple-combinatorial treatment comprising temozolomide along with chloroquine, naringenin, and phloroglucinol in an orthotopic glioma-induced xenograft model.

METHODS

Antiproliferative effect of the drugs was assessed by immunostaining. The expression profiles of WNT/β-catenin and apoptotic markers were evaluated by qRT-PCR, immunoblotting, and ELISA. Patterns of mitochondrial depolarization was determined by flow cytometry. TUNEL assay was performed to affirm apoptosis induction. In vivo drug detection study was carried out by ESI-Q-TOF MS analysis.

RESULTS

The quadruple-drug treatment had significantly hampered glioma proliferation and had induced apoptosis by modulating the WNT/β-catenin signaling. Interestingly, the induction of apoptosis was associated with mitochondrial depolarization. The quadruple-drug cocktail had breached the blood-brain barrier and was detected in the brain tissue and plasma samples.

CONCLUSION

The quadruple-drug combination served as a promising adjuvant therapy to combat glioblastoma lethality in vivo and can be probed for translation from bench to bedside.

Therapeutic intervention of glioma with the novel antineoplastic agent T11TS: the story so far

The disease relevance of novel therapeutic agent T11TS, established first by the authors' group, was shown to ameliorate experimental glioma through multimodal mechanistic activities. T11TS reverses immunosuppression in glioma, causing profound effects on immune potentiation via peripheral, intracranial and hematopoietic cells. T-cell signaling in glioma is reversed by T11TS, modulating cytokine levels and favoring apoptotic killing of glioma cells. T11TS arrests the glioma cell cycle at the G1 phase via activation of p21. VEGF downregulation hypophosphorylates the Akt pathway. T11TS hinders endothelial cell progression and metastasis by arresting matrix degradation, inhibiting the Ras-Raf and Akt-PTEN pathways and initiating inflammatory changes, causing apoptosis. T11TS is effective against in vitro human glioma. Toxicity studies demonstrate that T11TS is nontoxic. The authors' study promise translational research with T11TS.

T11TS repress gliomagenic apoptosis of bone marrow hematopoietic stem cells

Combating gliomagenic global immunosuppression is one of the emerging key for improving prognosis in malignant glioma. Apoptosis plays a pivotal role within the adult hematopoietic system particularly in regulating the cells of immune system. Gliomagenic regulation of apoptotic mediators within bone marrow milieu has not been elucidated. We previously demonstrated that administration of membrane glycopeptides T11 target structure (T11TS) not only rejuvenate bone marrow hematopoietic stem cells (BMHSCs) from glioma mediated hibernation by inhibiting gliomagenic overexpression of Ang-1/Tie-2 but also stimulate glioma mediated diminution of expression CD34, c-kit, and Sca-1 markers. In the present study, we investigated the impact of glioma on apoptotic signaling cascades of BMHSCs and consequences following T11TS therapy. Bone marrow smear and Annexin V staining confirm gliomagenic acceleration of apoptotic fate of BMHSCs whereas T11TS treatment in glioma-bearing rats disrupted apoptosis of BMHSCs. Flowcytometry, immunoblotting, and immunofluorescence imagining results revealed multi potent T11TS not only significantly downregulates gliomagenic overexpression of Fas, Fas L, Bid, and caspase-8, the pro-apoptotic extrinsic mediators but also strongly inhibits cytosolic release of cytochrome-c, Apf-1, and Bax to deactivate gliomagenic caspase-9, 3 the key intrinsic apoptotic mediators followed by up modulation of anti-apoptotic Bcl-2 in glioma associated HSCs. T11TS is also able to diminish the perforin-granzyme B mediated apoptotic verdict of BMHSCs during gliomagenesis. The anti-apoptotic action of T11TS on glioma associated BMHSCs provide a crucial insight into how T11TS exerts its immunomodulatory action against glioma mediated immune devastation.

Cigarette smoke extracts induce overexpression of the proto-oncogenic gene interleukin-13 receptor α2 through activation of the PKA-CREB signaling pathway to trigger malignant transformation of lung vascular endothelial cells and angiogenesis

Cigarette smoking is a major cause of lung cancer. Tumor-associated endothelial cells (TAECs) play important roles in tumor angiogenesis and metastasis. However, whether cigarette smoking can trigger genesis of lung TAECs has not been reported yet. In the current study, we used lung endothelial cell (EC) lines as a model to study the pathological effect of cigarette smoke extracts (CSEs) on human lung ECs, and found that a lower dose of 4% CSEs obviously caused abnormal morphological changes in ECs, increased the permeability of endothelial monolayer, while a higher concentration of 8% CSEs caused EC apoptosis. Strikingly, CSEs induced a 117-fold overexpression of a pro-tumorigenic interleukin-13 receptor α2 gene (IL-13Rα2, also named as CT-19) through activation of the protein kinase A (PKA) and cAMP response element-binding protein (CREB) signaling pathway. A PKA specific inhibitor H89 completely abolished CSEs-induced IL-13Rα2 overexpression. The overexpression of IL-13Rα2 in lung ECs significantly increased the tumorigenic, migratory, and angiogenic capabilities of the cells, suggesting that IL-13Rα2 promotes genesis of lung TAECs. Together, our data show that CSEs activate the PKA, CREB, and IL-13Rα2 axis in lung ECs, and IL-13Rα2 promotes the malignant transformation of lung ECs and genesis of TAECs with robust angiogenic and oncogenic capabilities. Our study provides new insight into the mechanism of CSEs-triggered lung cancer angiogenesis and tumorigenesis, suggesting that the PKA-CREB-IL-13Rα2 axis is a potential target for novel anti-lung tumor angiogenesis and anti-lung cancer drug discovery.