Confocal Raman data analysis enables identifying apoptosis of MCF-7 cells caused by anticancer drug paclitaxel

Abstract

Abstract. Confocal Raman microscopy is a noninvasive, label-free imaging technique used to study apoptosis of live MCF-7 cells. The images are based on Raman spectra of cells components, and their apoptosis is monitored through diffusion of cytochrome c in cytoplasm. K-mean clustering is used to identify mitochondria in cells, and correlation analysis provides the cytochrome c distribution inside the cells. Our results demonstrate that incubation of cells for 3 h with 10 μM of paclitaxel does not induce apoptosis in MCF-7 cells. On the contrary, incubation for 30 min at a higher concentration (100 μM) of paclitaxel induces gradual release of the cytochrome c into the cytoplasm, indicating cell apoptosis via a caspase independent pathway.

Probing differentiation in cancer cell lines by single-cell micro-Raman spectroscopy

“…In the present series of measurements, we acquired spectra from both the cytoplasm and nucleus regions but did not discern any significant difference between the spectral features that we measured for differentiated and undifferentiated cells vis-à-vis the intensities of protein and DNA/RNA peaks of interest in the present study. It is noteworthy that some earlier work 16,17 has, indeed, reported that spectra measured from cytoplasm or nucleus exhibit different features. We note that spectral differences between cytoplasm and nucleus in the study of Matthäus et al 16 was based on analysis the of C─H vibrations in the 2800 to 3000 cm −1 region.…”

“…Our spectral region of interest is 500 to 1800 cm −1 and it is, therefore, not possible for us to make comparisons with features that appear in the 2800 to 3000 cm −1 region. The other study 17 is a confocal Raman study and, again, lack of depth information in our experiments precludes direct comparisons to be made.…”

Label‐Free Molecular Imaging of Biological Cells and Tissues by Linear and Nonlinear Raman Spectroscopic Approaches

“…[67] TheR aman study detected large panitumumab-induced differences in cells expressing wild-type K-Ras,b ut not in cells with oncogenic K-Ras mutations.O ther works monitored the effects of the anticancer drug docetaxel on the morphology and biochemistry of living colon cancer cells, [68] the anticancer drug paclitaxel on MCF-7 breast cancer cells, [69] the chemotherapeutic drug doxorubicin on lymphocytes, [70] and the antitumor drugs gemcitabine on living nonsmall lung cancer cells Calu-1 [71] and cisplatin on nasopharyngeal carcinoma cells [72] by Raman microscopic imaging. [67] TheR aman study detected large panitumumab-induced differences in cells expressing wild-type K-Ras,b ut not in cells with oncogenic K-Ras mutations.O ther works monitored the effects of the anticancer drug docetaxel on the morphology and biochemistry of living colon cancer cells, [68] the anticancer drug paclitaxel on MCF-7 breast cancer cells, [69] the chemotherapeutic drug doxorubicin on lymphocytes, [70] and the antitumor drugs gemcitabine on living nonsmall lung cancer cells Calu-1 [71] and cisplatin on nasopharyngeal carcinoma cells [72] by Raman microscopic imaging.…”

Types of cell death and apoptotic stages in Chinese Hamster Ovary cells distinguished by Raman spectroscopy

“…Several st udies have investigated the use of Raman spectroscopy as a tool for distinguishing apoptotic cells in cancer cell lines. They have mainly reported decreased nucleic acid signals and increased lipid signals in Raman spectra (Krafft, Knetschke, Funk, & Salzer, ; Ong, Lim, & Liu, ; Owen et al, ; Salehi et al, ; Verrier, Notingher, Polak, & Hench, ; Zoladek, Pascut, Patel, & Notingher, ), although the reported changes are not always consistent with one another. One study distinguished the stages of apoptosis from induced cells negative for Annexin V and PI staining in two skin cancer cell lines (Saos‐2 and SW‐1353) (Brauchle, Thude, Brucker, & Schenke‐Layland, ), but comparisons were not made between control cells and induced apoptotic populations, or between apoptosis and other modes of cell death.…”