OBJECTIVE: The effects of single targeted 2 Gy and 8 Gy gamma-ray irradiations on the immune cell population (lymphocytes, B-cells, T-cells, neutrophils, eosinophils, and macrophages) in EMT6 mouse-bearing tumour models was investigated.
METHODS: The effects of both irradiation doses in early (96 hours) and acute phase (5 to 11 days) post-irradiation on immune parameters were monitored in blood circulation and TME using flow cytometry. Simultaneously, selected cytokines related to immune cells within the TME were measured using multiplex ELISA.
RESULTS: A temporary reduction in systemic total white blood count (TWBC) resulted from an early phase (96 hours) of gamma-ray irradiation at 2 Gy and 8 Gy compared to sham control group. No difference was obtained in the acute phase. Neutrophils dominated among other immune cells in TME in sham control group. Eosinophils in TME was significantly increased after 8 Gy treatment in acute phase compared to sham control (p< 0.005). Furthermore, the increment of tumour necrosis (TNF)-α, eotaxin and interleukin (IL)-7 (p< 0.05) in both treatment groups and phases were associated with anti-tumour activities within TME by gamma-ray irradiation.
CONCLUSION: The temporary changes in immune cell populations within systemic circulation and TME induced by different doses of gamma-ray irradiation correlated with suppression of several pro-tumorigenic cytokines in mouse-bearing EMT6 tumour models.
MATERIALS AND METHODS: Thirty-nine formalin-fixed paraffin-embedded ameloblastoma cases comprising unicystic ameloblastoma (n=19) and solid/multicystic ameloblastoma (n=20) were subjected to IHC staining for IL-1α, IL-1β, IL-6 and IL-8. A semi-quantitative method was used to evaluate the expression levels of these cytokines according to cell types in the tumoural parenchyma and stroma.
RESULTS: Major findings were upregulations of IL-1α and IL-6 in SMA compared to UA. Both cytokines were heterogeneously detected in the tumoural parenchyma and stroma. Within the neoplastic epithelial compartment, IL-1α expression was more frequently detected in PA-like cells in UA whereas it was more frequently encountered in SR-like cells in SMA. IL-6 demonstrated higher expression levels in the stromal compartment of SMA. IL-1β and IL-8 were markedly underexpressed in both tumour subsets.
CONCLUSIONS: Overexpression of IL-1α in SMA suggests that this growth factor might play a role in promoting bone resorption and local invasiveness in this subtype. The expression levels of IL-1α and IL-6 in three cellular localizations indicate that parenchymal-stromal components of ameloblastoma interact reciprocally via IL-1α and IL-6 to create a microenvironment conducive for tumour progression.
MAIN BODY: This review highlights the roles of CSCs in tumour initiation, progression and metastasis with a focus on the cellular and molecular regulators that influence their phenotypical changes and behaviours in the different stages of cancer progression. We delineate the cross-talks between CSCs with the tumour microenvironment that support their intrinsic properties including survival, stemness, quiescence and their cellular and molecular adaptation in response to therapeutic pressure. An insight into the distinct roles of CSCs in promoting angiogenesis and metastasis has been captured based on in vitro and in vivo evidences.
CONCLUSION: Given dynamic cellular events along the cancer progression and contributions of resistance nature by CSCs, understanding their molecular and cellular regulatory mechanism in a heterogeneous nature, provides significant cornerstone for the development of CSC-specific therapeutics.