Typical morphological change of apoptotic cells was easily observ

Typical morphological change of apoptotic cells was easily observed, which showed characteristic of chromatin condensation and nuclear fragmentation. In fact, we observed a 25.58 ± 3.86 (SD) % of apoptotic cells after administration of SR140333 while only 7.85 ± 1.53 (SD) % in the untreated cells (p < 0.01). Figure 5 Hoechst33258 fluorescent staining after SR140333 treatment (A, SR140333 treated cells; B, control). T47D cells were cultured in DMEM contained 10%FBS and SR140333 was added at logarithmic growth phase (on day

3, at about 30% cell confluences). We carried out Hoechst33258 staining on specimens obtained by the cover slip culture method. After click here treated with SR140333 for 24 h, T47D cells showed slower SHP099 datasheet proliferation profile and visible apoptosis was detected by Hoechst33258. Discussion Our present study has clearly demonstrated expression of NK-1 in breast cancer tissues and T47D Ro-3306 order cell line using immunohistochemical study. This result is in agreement with the previous study which demonstrated that NK-1 is increased in breast biopsies by in situ hybridization [2]. Moreover, previous study has shown that malignant breast tissues bear over-expression of substance P [2], indicating involvement of neuroendocrine mechanism in breast cancer development. NK-1 receptors in tumor cells increase the amount of mitotic signals for the tumor cell, counteracting the different apoptotic

and/or pro-senescent pathways

activated in the neoplastic cell population [24]. In breast cancers, increasing substance P could enhance the message transmitting Flavopiridol (Alvocidib) through increasing NK-1; this may accelerate the proliferation process. The increasing number of NK-1 in T47D cells leads us to investigate the role of NK-1 in tumor cell proliferation and growth. Therefore, we performed an in vitro study in which NK-1 receptors were activated or blocked by specific agonist SMSP or specific antagonist SR140333. The data of this study have shown, for the first time, that SMSP could stimulate the proliferation of breast cancer cell line T47D while SR140333 showed growth inhibitory effect. Further study by MTT assay has shown that SR140333 counteracted SMSP induced proliferation of T47D cells in vitro. These results suggest that the downstream signal transduction following NK-1 activation is significant for breast cancer development. It is known that substance P stimulates mitogenesis by activating NK-1 receptors in several neoplastic cell types [25, 18, 4–11]. Since we merely exerted SMSP not exogenous substance P in this study, the exact effect of substance P on breast cancer cell line is still unclear. As endogenous substance P exhibits high affinity to NK-1 in vivo [10, 11], the present study suggests that NK-1 plays a central role in substance P related cell proliferation in T47D cells.

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