Combination of proteasome and HDAC inhibitor enhances HPV16 E7-specific CD8+ T cell immune response and antitumor effects in a preclinical cervical cancer model

Background

Bortezomib, a proteasome inhibitor and suberoylanilide hydroxamic acid (SAHA, also known as Vorinostat), a histone deacetylase inhibitor, have been recognized as potent chemotherapeutic drugs. Bortezomib and SAHA are FDA-approved for the treatment of cutaneous T cell lymphoma and multiple myeloma/mantle cell lymphoma, respectively. Furthermore, the combination of the bortezomib and SAHA has been tested in a variety of preclinical models and in clinical trials and may be ideal for the treatment of cancer. However, it remains unclear how this treatment strategy affects the host immune response against tumors.

Results

Here, we used a well-defined E6/E7-expressing tumor model to examine how the immune system can be motivated to act against tumor cells expressing tumor antigens. We demonstrate that the combination of bortezomib and SAHA elicits potent antitumor effects in TC-1 tumor-bearing mice. Additionally, we are the first to show that treatment with bortezomib and SAHA leads to tumor-specific immunity by rendering tumor cells more susceptible to killing by antigen-specific CD8+ T cells than treatment with either drug alone.

Conclusions

The current study serves an important foundation for the future clinical application of both drugs for the treatment of cervical cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12929-014-0111-1) contains supplementary material, which is available to authorized users.

Sequential cisplatin therapy and vaccination with HPV16 E6E7L2 fusion protein in saponin adjuvant GPI-0100 for the treatment of a model HPV16+ cancer

Clinical studies suggest that responses to HPV16 E6E7L2 fusion protein (TA-CIN) vaccination alone are modest, and GPI-0100 is a well-tolerated, potent adjuvant. Here we sought to optimize both the immunogenicity of TA-CIN via formulation with GPI-0100 and treatment of HPV16+ cancer by vaccination after cisplatin chemotherapy. HPV16 neutralizing serum antibody titers, CD4+ T cell proliferative and E6/E7-specific CD8+ T cell responses were significantly enhanced when mice were vaccinated subcutaneously (s.c.) or intramuscularly (i.m.) with TA-CIN formulated with GPI-0100. Vaccination was tested for therapy of mice bearing syngeneic HPV16 E6/E7+ tumors (TC-1) either in the lung or subcutaneously. Mice treated with TA-CIN/GPI-0100 vaccination exhibited robust E7-specific CD8+ T cell responses, which were associated with reduced tumor burden in the lung, whereas mice receiving either component alone were similar to controls. Since vaccination alone was not sufficient for cure, mice bearing s.c. TC-1 tumor were first treated with two doses of cisplatin and then vaccinated. Vaccination with TA-CIN/GPI-0100 i.m. substantially retarded tumor growth and extended survival after cisplatin therapy. Injection of TA-CIN alone, but not GPI-0100, into the tumor (i.t.) was similarly efficacious after cisplatin therapy, but the mice eventually succumbed. However, tumor regression and extended remission was observed in 80% of the mice treated with cisplatin and then intra-tumoral TA-CIN/GPI-0100 vaccination. These mice also exhibited robust E7-specific CD8+ T cell and HPV16 neutralizing antibody responses. Thus formulation of TA-CIN with GPI-0100 and intra-tumoral delivery after cisplatin treatment elicits potent therapeutic responses in a murine model of HPV16+ cancer.

From the camp pathway to search the ketamine-related learning and memory

Protein kinase A (PKA) phosphorylates and activates cAMP response element-binding protein (CREB), which then binds to CRE domain on DNA and in turn activates genes involved in the process of learning and memorization. It has been demonstrated that CREB is involve in the learning and memory deficits that are caused by ketamine. In this review, we attempt to discuss the role of ketamine and cAMP pathway and relevant regulatory protein ERK in learning and memory through the molecular mechanism and signaling pathways. In this review, we also try to find a new way to treat the impairment in learning and memory induced by ketamine.

Explanation of colon cancer pathophysiology through analyzing the disrupted homeostasis of bile acids

BACKGROUND

The colon plays a key role in regulating the homeostasis of bile acids.

AIM

The present study aims to evaluate the influence of colon cancer towards the homeostasis of bile acids.

METHODS

The free and conjugated bile acids were determined using ultraperformance LC (UPLC) coupled with ABI 4000 QTRAP triple quadrupole instruments.

RESULTS

The results showed that the free bile acids in serum of patients with colon cancers tend to increase, and the conjugated bile acids tended to decrease, especially for taurolithocholate (TLCA) (p<0.001).

CONCLUSION

The alteration of bile acids balance in colon cancers indicated the possibility of complicated diseases due to the disrupted balance of bile acids.

The phosphodiesterase-4 inhibitor Ro 20-1724 reverses learning and memory impairments, and downregulation of CREB in the hippocampus and cortex induced by ketamine anesthesia in immature rats

AIM

The objective of the study was to examine the effects and possible mechanisms of phosphodiesterase-4 inhibitor Ro 20-1724 on learning and memory impairments induced by ketamine anesthesia. Further, expression the cAMP response element binding proteins (CREB), transcription factors involved in long-term memory, were analyzed in conjunction with these effects of Ro 20-1724.

METHODS

Ninety-six immature (21-day-old) Sprague-Dawley rats were divided into eight groups. To assess the learning and memory impairments, Morris Water Maze task was used. Expression of total and phosphorylated CREB in the hippocampus and cerebral cortex was evaluated by Western blot.

RESULTS

THE escape latency and frequency of passing the platform in Morris Water Maze task were markedly longer after ketamine anesthesia. However, treatment with Ro 20-1724 significantly (P<0.05) improved both learning and memory performance. Further, administration of Ro 20-1724 reverted the down-regulation of total and phosphorylated CREB caused by ketamine (P<0.05), as demonstrated by Western blot analysis of CREB expression in the hippocampus and cortex.

CONCLUSION

Treatment with Ro 20-1724 improves learning and memory deficits caused by ketamine anesthesia in immature rats, possibly via increases in expression of total and phosphorylated CREB in the hippocampus and cerebral cortex.

Expression profile of Nanos2 gene in dairy goat and its inhibitory effect on Stra8 during meiosis

OBJECTIVES

Nanos2, an RNA-binding protein, belongs to the Nanos gene-coding family and contains two CCHC zinc-finger motifs. In mouse, it plays a pivotal role in male germ cell development, and self-renewal of spermatogonial stem cells. However, little is known of its expression pattern and functions in dairy goat testis.

MATERIALS AND METHODS

Immunohistochemistry and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) were used to generate the expression profile of Nanos2 in dairy goat testis. Furthermore, its overexpression effects on male germline stem cells (mGSCs) were studied using qRT-PCR, immunofluorescence, dual-luciferase reporter assay and western blotting.

RESULTS

Nanos2 is a conservative gene expressed widely in various tissues, especially in pancreas, and it displays higher expression in adult testes than in other age groups. Overexpression of Nanos2 significantly downregulated meiosis-related genes, including Stra8 and Scp3, which induced inhibition of meiosis. Results from dual-luciferase reporter assay and western blotting indicated that Nanos2 directly downregulated Stra8 in goat GmGSCs.

CONCLUSIONS

Taken together, these results suggest that Nanos2 plays an important role in spermatogonia and that its overexpression restrained meiosis in the dairy goat.

MHC-Ig induces memory T cell formation in vivo and inhibits tumour growth

Induction of a T cell mediated immune response is critical for the eradication of viral infections and tumours. Soluble peptide-loaded major histocompatibility complex-Ig (^pep−MHC-Ig) have been shown to bind their cognate ligands, T cell receptor, with high affinity, and are successfully used to visualize antigen-specific T cells. Furthermore, immobilized ^pep−MHC-Ig can activate and expand antigen-specific T cells in vitro and in vivo. In this study, we investigate the use of ^pep−MHC-Ig as a potential strategy to modulate antigen specific T cell immune responses in vivo. ^SIY−K^b-Ig immunization, together with the pre-activation by an anti-CD40 monoclonal antibody, is able to stimulate a strong expansion of adoptively transferred 2C transgenic T cells and the formation of long term antigen-specific memory T cells. In addition, mechanistic studies show that the ^pep−MHC-Ig molecules directly activate T cells in vivo without requiring uptake and reprocessing by antigen-presenting cells. Furthermore, B6 mice immunized with ^pep−MHC-Ig molecules inhibit tumour growth in a B16-SIY melanoma prevention model. Thus, soluble ^pep−MHC-Ig molecules represent a powerful tool for active immunotherapy.