Dataset Information

Gemcitabine enhances the efficacy of reovirus-based oncotherapy through anti-tumour immunological mechanisms.

ABSTRACT:

Background

Reovirus preferentially infects and kills cancer cells and is currently undergoing clinical trials internationally. While oncolysis is the primary mode of tumour elimination, increasing evidence illustrates that reovirus additionally stimulates anti-tumour immunity with a capacity to target existing and possibly relapsing cancer cells. These virus-induced anti-tumour immune activities largely determine the efficacy of oncotherapy. On the other hand, anti-viral immune responses can negatively affect oncotherapy. Hence, the strategic management of anti-tumour and anti-viral immune responses through complementary therapeutics is crucial to achieve the maximum anti-cancer benefits of oncotherapy.

Methods

Intra-peritoneal injection of mouse ovarian surface epithelial cells (ID8 cells) into wild-type C57BL/6 mice was treated with a therapeutic regimen of reovirus and/or gemcitabine and then analysed for prolonged survival, disease pathology, and various immunological parameters. Furthermore, in vitro analyses were conducted to assess apoptosis, viral spread, and viral production during reovirus and/or gemcitabine treatment.

Results

We demonstrate that reovirus and gemcitabine combination treatment postpones peritoneal carcinomatosis development and prolongs the survival of cancer-bearing hosts. Importantly, these anti-cancer benefits are generated through various immunological mechanisms, including: (1) inhibition of myeloid-derived suppressor cells recruitment to the tumour microenvironment, (2) downmodulation of pro-MDSC factors, and (3) accelerated development of anti-tumour T-cell responses.

Conclusion

The complementation of reovirus with gemcitabine further potentiates virus-initiated anti-cancer immunity and enhances the efficacy of oncotherapy. In the context of ongoing clinical trials, our findings represent clinically relevant information capable of enhancing cancer outcomes.

SUBMITTER: Gujar SA

PROVIDER: S-EPMC3887295 | biostudies-literature | 2014 Jan

REPOSITORIES: biostudies-literature

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Publications

Gemcitabine enhances the efficacy of reovirus-based oncotherapy through anti-tumour immunological mechanisms.

Gujar S A SA Clements D D Dielschneider R R Helson E E Marcato P P Lee P W K PW

British journal of cancer 20131126 1

<h4>Background</h4>Reovirus preferentially infects and kills cancer cells and is currently undergoing clinical trials internationally. While oncolysis is the primary mode of tumour elimination, increasing evidence illustrates that reovirus additionally stimulates anti-tumour immunity with a capacity to target existing and possibly relapsing cancer cells. These virus-induced anti-tumour immune activities largely determine the efficacy of oncotherapy. On the other hand, anti-viral immune responses ...[more]

PMID: 24281006

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Project description:Patients with medullary thyroid cancer (MTC) are often diagnosed with spread tumour disease and the development of better systemic treatment options for these patients is important. Treatment with the radiolabelled somatostatin analogue 177Lu-octreotate is already a promising option but can be optimised. For example, combination treatment with another substance could increase the effect on tumour tissue. Gemcitabine is a nucleoside analogue that has been shown to sensitise tumour cells to radiation. The aim of this study was to investigate potentially additive or synergistic effects of combining radiation with gemcitabine for treatment of MTC. Nude mice transplanted with patient-derived MTC tumours (GOT2) were divided into groups and treated with radiation and/or gemcitabine. Radiation treatment was given as 177Lu-octreotate or external beam radiotherapy (EBRT). The volume of treated and untreated tumours was followed. The absorbed dose and amount of gemcitabine were chosen to give moderate tumour volume reduction when given as monotherapy to enable detection of increased effects from combination treatment. After follow-up, the mice were killed and tumours were immunohistochemically (IHC) analysed. Overall, the animals that received a combination of EBRT and gemcitabine showed the largest reduction in tumour volume. Monotherapy with EBRT or gemcitabine also resulted in a clear detrimental effect on tumour volume, while the animals that received 177Lu-octreotate monotherapy showed similar response as the untreated animals. The GOT2 tumour was confirmed in the IHC analyses by markers for MTC. The IHC analyses also revealed that the proliferative activity of tumour cells was similar in all tumours, but indicated that fibrotic tissue was more common after EBRT and/or gemcitabine treatment. The results indicate that an additive, or even synergistic, effect may be achieved by combining radiation with gemcitabine for treatment of MTC. Future studies should be performed to evaluate the full potential of combining 177Lu-octreotate with gemcitabine in patients.

Dataset Information

Gemcitabine enhances the efficacy of reovirus-based oncotherapy through anti-tumour immunological mechanisms.

Background

Methods

Results

Conclusion

Publications

Gemcitabine enhances the efficacy of reovirus-based oncotherapy through anti-tumour immunological mechanisms.

Similar Datasets

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