364
H. J. Byrne et al.
cervical cancer [66], 99.7 % of invasive cervical neoplasia being associated with
hPv infection [67]. Identifying the presence of hPv is a very important factor in
the prevention of cervical cancer and thus, hPv testing has been added to the range
of clinical options for cervical cancer screening. hPv testing is based on detecting
the dNA of the virus. It has been found that the dNA of high risk strains of hPv
is assimilated within the cellular dNA of the host [68]. A drawback to hPv testing
is that it is more expensive and time-consuming than other screening tests, and it
requires a sophisticated laboratory infrastructure.
Raman spectroscopy has also been used to study cell lines derived from the
cervix, revealing spectral variations, mostly in peaks originating from dNA and
proteins, in cell lines expressing the E7 gene of hPv-16 compared to cells not
affected by hPv [69]. Furthermore, it has been demonstrated that, in low-grade
cytology infected with high-risk oncogenic hPv16 or hPv18, it was possible to
differentiate samples from women based on whether they were aged 20–29 vs.
30–39 years using attenuated total reflection infrared spectroscopy [70].
to further demonstrate the potential of vibrational spectroscopy for clinical
screening, four cervical cancer cell lines were investigated using both Raman and
FtIR spectroscopy; hPv negative C33A, hPv-18 positive heLa with 20–50 integrated hPv copies per cell, hPv-16 positive Siha with 1–2 integrated hPv strands
per cell and hPv-16 positive CaSki containing 60–600 integrated hPv copies per
cell. the main aim of the experiment was to investigate biochemical changes in cells
caused by high risk hPv strands (hPv-16 and hPv-18) and to examine whether it
is possible to differentiate between the cells with no hPv copies and cells infected
by low number, medium number and high number of integrated hPv copies, using
vibrational spectroscopic techniques. Both common forms of vibrational spectroscopy, Raman and Fourier transform Infrared absorption, were used to gain complementary information [63]. the Raman spectroscopic analysis is discussed here.
A horiba Jobin Yvon LabRam 800hR was employed for the measurement, operating at a wavelength of 532 nm and utilising a x100 objective. After incubation,
cells were centrifuged to form pellets and washed thoroughly before measurement.
the mean of 30 Raman spectra recorded from two pellets (approximately 15 spectra per pellet) for C33A, Siha, heLa and CaSki cell lines were derived from the
raw spectra via the pre-processing procedures and are presented in Fig. 13.4. Assignments of the main peaks (numbered in Fig. 13.4) are shown in table 13.1. In
the mean Raman spectra, almost no significant differences between hPv negative
C33A and Siha cells, containing 1–2 hPv copies per cells (low hPv concentration) are discernible. only the peak at 1,583 cm
−1
assigned to dNA/RNA and Phenylalanine vibrations was found to vary between C33A and Siha cells. For cells
containing a higher number of integrated hPv copies per cell, heLa cells (medium
hPv concentration) and CaSki cells (high hPv concentration), the observed differences are more prominent for protein, nucleic acid and lipid vibrations. CaSki
cells exhibited a significant increase in Amide I (proteins) intensity at 1,660 cm
−1
and a decrease in lipid levels at 1,093, 1,311 and 1,450 cm
−1
compared to C33A,
Siha and heLa. hPv presence in a cell appears to change protein expression, which
may result in the protein variations observed in the Raman spectra, primarily for
H. J. Byrne et al.
cervical cancer [66], 99.7 % of invasive cervical neoplasia being associated with
hPv infection [67]. Identifying the presence of hPv is a very important factor in
the prevention of cervical cancer and thus, hPv testing has been added to the range
of clinical options for cervical cancer screening. hPv testing is based on detecting
the dNA of the virus. It has been found that the dNA of high risk strains of hPv
is assimilated within the cellular dNA of the host [68]. A drawback to hPv testing
is that it is more expensive and time-consuming than other screening tests, and it
requires a sophisticated laboratory infrastructure.
Raman spectroscopy has also been used to study cell lines derived from the
cervix, revealing spectral variations, mostly in peaks originating from dNA and
proteins, in cell lines expressing the E7 gene of hPv-16 compared to cells not
affected by hPv [69]. Furthermore, it has been demonstrated that, in low-grade
cytology infected with high-risk oncogenic hPv16 or hPv18, it was possible to
differentiate samples from women based on whether they were aged 20–29 vs.
30–39 years using attenuated total reflection infrared spectroscopy [70].
to further demonstrate the potential of vibrational spectroscopy for clinical
screening, four cervical cancer cell lines were investigated using both Raman and
FtIR spectroscopy; hPv negative C33A, hPv-18 positive heLa with 20–50 integrated hPv copies per cell, hPv-16 positive Siha with 1–2 integrated hPv strands
per cell and hPv-16 positive CaSki containing 60–600 integrated hPv copies per
cell. the main aim of the experiment was to investigate biochemical changes in cells
caused by high risk hPv strands (hPv-16 and hPv-18) and to examine whether it
is possible to differentiate between the cells with no hPv copies and cells infected
by low number, medium number and high number of integrated hPv copies, using
vibrational spectroscopic techniques. Both common forms of vibrational spectroscopy, Raman and Fourier transform Infrared absorption, were used to gain complementary information [63]. the Raman spectroscopic analysis is discussed here.
A horiba Jobin Yvon LabRam 800hR was employed for the measurement, operating at a wavelength of 532 nm and utilising a x100 objective. After incubation,
cells were centrifuged to form pellets and washed thoroughly before measurement.
the mean of 30 Raman spectra recorded from two pellets (approximately 15 spectra per pellet) for C33A, Siha, heLa and CaSki cell lines were derived from the
raw spectra via the pre-processing procedures and are presented in Fig. 13.4. Assignments of the main peaks (numbered in Fig. 13.4) are shown in table 13.1. In
the mean Raman spectra, almost no significant differences between hPv negative
C33A and Siha cells, containing 1–2 hPv copies per cells (low hPv concentration) are discernible. only the peak at 1,583 cm
−1
assigned to dNA/RNA and Phenylalanine vibrations was found to vary between C33A and Siha cells. For cells
containing a higher number of integrated hPv copies per cell, heLa cells (medium
hPv concentration) and CaSki cells (high hPv concentration), the observed differences are more prominent for protein, nucleic acid and lipid vibrations. CaSki
cells exhibited a significant increase in Amide I (proteins) intensity at 1,660 cm
−1
and a decrease in lipid levels at 1,093, 1,311 and 1,450 cm
−1
compared to C33A,
Siha and heLa. hPv presence in a cell appears to change protein expression, which
may result in the protein variations observed in the Raman spectra, primarily for