Inhibition of 13-cis retinoic acid-induced gene expression of homeobox B7 by thalidomide

Thalidomide suppresses migration and invasion of colorectal cancer cells by inhibiting HOXB7-mediated activation of the Wnt/β-catenin signaling pathway

Heaps of studies have verified the effects of thalidomide (THA) on colorectal cancer (CRC). Howbeit, the corresponding mechanism awaits illustration, which is the foothold of this study. Following the treatment of 0, 1.94, 7.75, or 19.36 μM THA, CRC cell viability, apoptosis, migration, and invasion were evaluated by methyl tetrazolium, flow cytometry, wound-healing, and transwell assays. Homeobox B7 (HOXB7) expression in CRC was analyzed and detected by bioinformatics analysis, quantitative real-time PCR or western blot. After the corresponding transfection or treatment with inhibitor of catenin-responsive transcription-3 (iCRT-3), abovementioned CRC cell biological behaviors as well as expression levels of HOXB7 and β-catenin were evaluated. 7.75 and 19.36 μM THA dwindled CRC cell viability, migration, and invasion, and facilitated apoptosis. HOXB7 upregulation was detected in CRC cells, which promoted the viability, migration, invasion, and β-catenin expression, and weakened the apoptosis of CRC cells. Also, HOXB7 upregulation counteracted the effects of THA on CRC cells. iCRT-3 restrained β-catenin expression, viability, migration, and invasion, whereas promoting the apoptosis of CRC cells. In addition, iCRT-3 antagonized the effects of overexpressed HOXB7 on CRC cells. THA inhibits the migration and invasion of CRC cells, which is achieved by suppressing HOXB7-mediated activation of Wnt/β-catenin signaling pathway.

Current Opportunities for Targeting Dysregulated Neurodevelopmental Signaling Pathways in Glioblastoma

Glioblastoma (GBM) is the most common and highly lethal type of brain tumor, with poor survival despite advances in understanding its complexity. After current standard therapeutic treatment, including tumor resection, radiotherapy and concomitant chemotherapy with temozolomide, the median overall survival of patients with this type of tumor is less than 15 months. Thus, there is an urgent need for new insights into GBM molecular characteristics and progress in targeted therapy in order to improve clinical outcomes. The literature data revealed that a number of different signaling pathways are dysregulated in GBM. In this review, we intended to summarize and discuss current literature data and therapeutic modalities focused on targeting dysregulated signaling pathways in GBM. A better understanding of opportunities for targeting signaling pathways that influences malignant behavior of GBM cells might open the way for the development of novel GBM-targeted therapies.

Inhibition of 13-cis retinoic acid-induced gene expression of reactive-resistance genes by thalidomide in glioblastoma tumours in vivo

The cell differentiation potential of 13-cis retinoic acid (RA) has not succeeded in the clinical treatment of glioblastoma (GBM) so far. However, RA may also induce the expression of resistance genes such as HOXB7 which can be suppressed by Thalidomide (THAL). Therefore, we tested if combined treatment with RA+THAL may inhibit growth of glioblastoma in vivo. Treatment with RA+THAL but not RA or THAL alone significantly inhibited tumour growth. The synergistic effect of RA and THAL was corroborated by the effect on proliferation of glioblastoma cell lines in vitro. HOXB7 was not upregulated but microarray analysis validated by real-time PCR identified four potential resistance genes (IL-8, HILDPA, IGFBPA, and ANGPTL4) whose upregulation by RA was suppressed by THAL. Furthermore, genes coding for small nucleolar RNAs (snoRNA) were identified as a target for RA for the first time, and their upregulation was maintained after combined treatment. Pathway analysis showed upregulation of the Ribosome pathway and downregulation of pathways associated with proliferation and inflammation. In conclusion, combined treatment with RA + THAL delayed growth of GBM xenografts and suppressed putative resistance genes associated with hypoxia and angiogenesis. This encourages further pre-clinical and clinical studies of this drug combination in GBM.

HOXB7 expression by myeloma cells regulates their pro-angiogenic properties in multiple myeloma patients

The deregulation of the homeobox genes as homeoboxB (HOXB)-7 has been previously associated to tumor progression and angiogenesis; here we investigated the potential role of HOXB7 in the pro-angiogenic properties of multiple myeloma (MM) cells. We found that HOXB7 was expressed in 10 out of 22 MM patients analyzed at the diagnosis related to high bone marrow angiogenesis and overexpressed in about 40% of myeloma cell lines compared with normal plasma cells. Enforced HOXB7 expression in MM cells by a lentiviral vector significantly modified their transcriptional and angiogenic profile, checked by combined microarray and angiogenesis PCR analyses, upregulating VEGFA, FGF2, MMP2, WNT5a and PDGFA and downregulating thrombospoindin-2. The pro- and anti-angiogenic HOXB7-related gene signature was also validated in a large independent dataset of MM patients. Accordingly, MM-induced vessel formation was significantly increased by HOXB7 overexpression both in vitro angiogenic and chorioallantoic membrane assays, as well as the HOXB7 silencing by small interfering RNA inhibited the production of angiogenic factors, and the pro-angiogenic properties of MM cells. Finally, in SCID-NOD mice we confirmed that HOXB7 overexpression by MM cells stimulated tumor growth, increased MM-associated angiogenesis and the expression of pro-angiogenic genes by microarray analysis supporting the critical role of HOXB7 in the angiogenic switch in MM.