PURPOSE: The aim of the present work was to investigate the role of apoptosis inhibitor BIRC6 (baculoviral IAP repeat-containing protein 6) in breast cancer (BC), focusing particularly on its involvement in the metastatic cascade. METHODS: We analyzed BIRC6 mRNA expression levels and copy number variations in three BC databases from The Cancer Genome Atlas comparing clinical and molecular attributes. Genomic analysis was performed using the cBioPortal platform, whereas transcriptomic studies (mRNA expression levels, correlation heatmaps, survival plots, and gene ontology) were performed using USC Xena and R. Statistical significance was set at P < .05. RESULTS: Our bioinformatic analyses showed that there was a differential expression of BIRC6 in cancer samples when compared with normal samples. Copy number variations that involve amplification and gain of BIRC6 gene were correlated with negative hormone receptor tumors, higher prognostic indexes, younger age at diagnosis, and both chemotherapy and radiotherapy administration. Transcriptomic and gene ontology analyses showed that, under conditions of high BIRC6 mRNA levels, there are differential expression patterns in apoptotic, proliferation, and metastatic pathways. CONCLUSION: In summary, our in silico data suggest that BIRC6 plays an antiapoptotic, pro-proliferative, and apparent prometastatic role and could be a relevant molecular target for treatment of BC tumors.

Baculoviruses are insect-specific pathogens widely used in biotechnology. In particular, the Autographa californica nucleopolyhedrovirus (AcMNPV) has been exploited as a platform for bio-inputs production. This is why the improvement of the technologies used for the production of recombinant baculoviruses takes on particular relevance. To achieve this goal, we developed a highly versatile baculoviral transfer vector generation system called PluriBAC. The PluriBAC system consists of three insert entry levels using Golden Gate assembly technology. The wide availability of vectors and sticky ends allows enough versatility to combine more than four different promoters, genes of interest, and terminator sequences. Here, we report not only the rational design of the PluriBAC system but also its use for the generation of baculoviral reporter vectors applied to different fields of biotechnology. We demonstrated that recombinant AcMNPV baculoviruses generated with the PluriBAC system were capable of infecting Spodoptera frugiperda larvae. On the other hand, we found that the recombinant budded virions (BV) generated using our system were capable of transducing different types of tumor and normal cells both in vitro and in vivo. Our findings suggest that the PluriBAC system could constitute a versatile tool for the generation of insecticide and gene therapy vectors.

Diffuse gliomas (DGs) are malignant primary brain tumors originating from glial cells. This study aimed to investigate the role of Receptor-interacting protein kinase 1 (RIPK1) in DG pathology. The RIPK1 mRNA expression was analyzed in DG databases from The Cancer Genome Atlas (TCGA) containing clinical, genomic, and transcriptomic information from 670 patients. Transcriptomic studies were carried out using USC Xena and R, while in vitro assays were performed with the glioblastoma human cell line U251 and the commercial RIPK1 inhibitor GSK2982772. The results showed that high RIPK1 expression was linked to a lower survival probability in patients. Additionally, the RIPK1 expression was higher in the wtIDH samples compared to that in the mIDH samples. Significant differences in the expression of genes related to cellular dedifferentiation, proinflammatory cell death pathways, and tumor-infiltrating immune cells were found between high- and low-RIPK1 expression groups. To further characterize the role of RIPK1 in DG, the effects of the RIPK1 inhibitor were evaluated, alone or combined with cisplatin, on glioblastoma cell proliferation and apoptosis. The combined treatments effectively reduced cell proliferation and increased apoptosis. The overexpression of RIPK1 was associated with a poor prognosis for DG, suggesting that RIPK1 plays a critical role in glioma pathogenesis and should be considered in therapeutic decision-making.

BIRC6, a member of the inhibitor of apoptosis protein family (IAP), regulates apoptosis, autophagy and cytokinesis. IAPs are often overexpressed in tumors, contributing to oncogenesis, therapy resistance and worse prognosis. In particular, BIRC6 overexpression has been found in several tumor tissues. The aim of this study was to evaluate the effect of BIRC6 silencing on the apoptotic response of breast and lung tumor cells. We used RNA interference based on short hairpin RNA (shRNA) to knock down gene expression encoded by a recombinant baculovirus (BV), an insect-specific virus unable to replicate in mammalian hosts, to carry out preclinical validation tests in experimental models both in vitro and in vivo. Our results indicate that BIRC6 plays an antiapoptotic role in both breast and lung tumor cells. In vivo, treatment with BV-shBRIC6 reduced breast and lung tumor progression and increased overall survival. After histological analysis, BV-shBRIC6 was able to increase tumor necrosis. In addition, we demonstrated that BIRC6 expression correlates with antiapoptotic and tumor progression-relevant markers in lung and breast cancer patients. BV-based silencing of BIRC6 may have therapeutic value for the treatment of lung and breast tumors. Further translational studies of BV-shBIRC6 in lung and breast cancer are warranted.

Lepidopteran-infecting baculoviruses represent one of the most promising alternatives for pest biocontrol. In particular, Spodoptera frugiperda granulovirus (SfGV) infects the fall armyworm Spodoptera frugiperda , an increasingly important pest for maize and other crops around the world. SfGV has been investigated due to its capacity to enhance other baculovirus infectivity and as a biopesticide itself. Although the proteome of SfGV occlusion bodies (OB) is fundamental for their infectivity properties, we still lack a detailed understanding of its protein components and how they compare with other baculoviruses. To tackle this problem, we performed mass spectrometry-based proteomics analysis on SfGV OB obtained from infected larvae. We could detect 72 proteins included in SfGV OB and confirm the presence of two enhancins. EmPAI-based semi-quantification highlighted the presence of two granulovirus proteins, ORF101 and ORF141, shared with other GV proteomic studies. ORF101 was shown to form aggregates in insect cells. Bioinformatic analysis determined that ORF101 is an Ac5 family protein and at the same time shares striking similarities with AcMNPV P10. Prediction and comparison of OB protein structures allowed the detection of a common structural fold among 6 proteins PEP-1, PEP-2, Pep-P10, ORF007, ORF025, and Bro-f. Finally, comparison of four reported ODV proteomic studies of different GVs indicated that ORF040, ORF101, ORF141 and Bro-f are common components in GV OBs.