Adjuvant oncolytic virotherapy for personalized anti-cancer vaccination.

By conferring systemic protection and durable benefits, cancer immunotherapies are emerging as long-term solutions for cancer treatment. One such approach that is currently undergoing clinical testing is a therapeutic anti-cancer vaccine that uses two different viruses expressing the same tumor antigen to prime and boost anti-tumor immunity. By providing the additional advantage of directly killing cancer cells, oncolytic viruses (OVs) constitute ideal platforms for such treatment strategy. However, given that the targeted tumor antigen is encoded into the viral genomes, its production requires robust infection and therefore, the vaccination efficiency partially depends on the unpredictable and highly variable intrinsic sensitivity of each tumor to OV infection. In this study, we demonstrate that anti-cancer vaccination using OVs (Adenovirus (Ad), Maraba virus (MRB), Vesicular stomatitis virus (VSV) and Vaccinia virus (VV)) co-administered with antigenic peptides is as efficient as antigen-engineered OVs and does not depend on viral replication. Our strategy is particularly attractive for personalized anti-cancer vaccines targeting patient-specific mutations. We suggest that the use of OVs as adjuvant platforms for therapeutic anti-cancer vaccination warrants testing for cancer treatment.

Kaiso depletion attenuates transforming growth factor-ß signaling and metastatic activity of triple-negative breast cancer cells.

Triple-negative breast cancers (TNBCs) represent a subset of breast tumors that are highly aggressive and metastatic, and are responsible for a disproportionate number of breast cancer-related deaths. Several studies have postulated a role for the epithelial-to-mesenchymal transition (EMT) program in the increased aggressiveness and metastatic propensity of TNBCs. Although EMT is essential for early vertebrate development and wound healing, it is frequently co-opted by cancer cells during tumorigenesis. One prominent signaling pathway involved in EMT is the transforming growth factor-ß (TGFß) pathway. In this study, we report that the novel POZ-ZF transcription factor Kaiso is highly expressed in TNBCs and correlates with a shorter metastasis-free survival. Notably, Kaiso expression is induced by the TGFß pathway and silencing Kaiso expression in the highly invasive breast cancer cell lines, MDA-MB-231 (hereafter MDA-231) and Hs578T, attenuated the expression of several EMT-associated proteins (Vimentin, Slug and ZEB1), abrogated TGFß signaling and TGFß-dependent EMT. Moreover, Kaiso depletion attenuated the metastasis of TNBC cells (MDA-231 and Hs578T) in a mouse model. Although high Kaiso and high TGFßR1 expression is associated with poor overall survival in breast cancer patients, overexpression of a kinase-active TGFßR1 in the Kaiso-depleted cells was insufficient to restore the metastatic potential of these cells, suggesting that Kaiso is a key downstream component of TGFß-mediated pro-metastatic responses. Collectively, these findings suggest a critical role for Kaiso in TGFß signaling and the metastasis of TNBCs.

Expressing human interleukin-15 from oncolytic vesicular stomatitis virus improves survival in a murine metastatic colon adenocarcinoma model through the enhancement of anti-tumor immunity.

In this study, we sought to enhance the potency of an oncolytic virus, vesicular stomatitis virus (VSV), by inserting a transgene encoding a highly secreted version of human interleukin-15 (IL-15). IL-15 has shown promise as an immunotherapeutic cytokine, as it is able to enhance both natural killer (NK) and T-cell responses, but it has not yet been tested as a therapeutic transgene in the context of viral oncolysis. The transgene was modified to ensure enhanced secretion of IL-15 from infected cells, leading to strong localized expression from infected CT-26 tumors in vivo. This localized expression in the tumor microenvironment led to a clear enhancement to anti-tumoral T-cell responses and enhanced survival, while additional IL-15 administration systemically failed to further enhance the therapy. Overall, the transient localized expression of IL-15 in the tumour by an oncolytic virus was able to induce stronger anti-tumoral immunity in a murine model of colon carcinoma.

Protein modifications induced in mouse epidermis by potent and weak tumor-promoting hyperplasiogenic agents.

Two-dimensional gel electrophoresis was used to compare the changes in mouse epidermal proteins induced by the potent tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA), by the moderate promoter mechanical abrasion, and by the weakly promoting hyperplasiogenic agents mezerein and ethylphenylpropiolate. Evidence is presented which indicates that TPA caused many changes in the epidermal protein profiles especially related to the keratins which are the major differentiation product of the epidermis. The keratin modification progresses with time after TPA treatment, resulting in a keratin pattern which resembles that of newborn mouse epidermis. The criteria used for the identification of the keratins were extractability, isoelectric points, molecular weights, filament formation in vitro, immunological cross-reactivity, amino acid composition, and peptide mapping. Several other protein changes were evident in the more soluble epidermal proteins which were also prominent in the newborn epidermis. These protein alterations are observed not only early during the TPA induction of hyperplasia and inflammation at 48 and 72 hr but also in 1- and 2-week samples in which the morphology of the epidermis has returned to normal. Mezerein and abrasion produced protein changes similar to those induced by TPA. Ethylphenylpropiolate-induced protein modifications not only occurred at later times compared with either mezerein or TPA but also were less in magnitude. However, although many of the protein modifications induced by TPA appear to be associated with the hyperplasiogenic properties of TPA, the major difference between a potent promoter like TPA and a weak promoter like ethylphenylpropiolate appeared to be related to the magnitude of the response and the time of appearance of the protein changes.

Effect of sulfur dioxide on the morphology and mucin biosynthesis by the rat trachea.

Specific-pathogen-free rats were exposed to 400 ppm sulfur dioxide daily for up to 7 weeks. At intervals during exposure, tracheas were removed and incubated in vitro in culture medium containing radioactive glycoprotein precursors. The most prominent histological changes due to SO2 were progressive hypertrophy and hyperplasia of the submucosal mucous glands accompanied by a flattening of the epithelium with eventual recovery. Uptake of radioactive precursors into a highly purified mucin fraction correlated with these histological changes in the submucosal mucous glands, increasing progressively up to 4 times that of control. Uptake of precursors into specific mucins purified by DEAE-Sephacel showed that uptake into the 0.2 and 0.3 M NaCl fractions was stimulated several fold by SO2, and uptake into more highly acidic fractions, which was nearly absent in the control, was also greatly increased. Two weeks following the last exposure of the tracheas to SO2, their morphological and mucus-secreting properties showed signs of returning to that of the control.

Reestablishment of a mucociliary epithelium in tracheal organ cultures exposed to retinyl acetate: a biochemical and morphometric study.

Tracheal explants derived from vitamin A-deficient rats underwent keratinizine squamous metaplasia in organ culture when grown in serum-free medium. Within 1 d after the addition of 0.1, 2, or 10 microgram retinyl acetate per ml of medium, there was a concentration-dependent increase in the uptake of [3H]glucosamine and [14C]serine into both the total mucous glycoprotein and the principal purified mucin fraction eluted from a DEAE-Sephacel column with 0.2 M NaCl. The stimulation of mucin synthesis continued throughout the 21-d exposure period in a concentration-dependent fashion. It was also found that vitamin A had a greater effect on the incorporation of [3H]glucosamine than on [14C]serine into the secreted mucins, particularly at the higher retinyl acetate concentrations. This result indicated a greater effect of the vitamin on the synthesis of the carbohydrate moiety of the mucins. Morphological analysis by light and electron microscopy demonstrated that the keratinizing squamous epithelium began to revert to a mucus-secreting tissue as early as 24 h after addition of 10 microgram retinyl acetate to the medium. The response was slower with the lower vitamin concentrations. Stereological analysis revealed that the increase in the volume fraction of the Golgi apparatus reached a stable level which could not be altered with continued exposure to retinyl acetate, but that the volume fraction of mucin droplets continually increased and apparently did not reach a maximum in the 21-d exposure period. Conversely, the volume fraction of filament bundles and the number of desmosomes decreased during the vitamin A treatment.