Figure 1.
Thermogram profiles associated with progressive cervical disease.
Mean thermogram profiles of excess specific heat capacity (Cpex) versus temperature (Panel A) and standard deviation (Panel B) of each clinical group: controls (black); LSIL (red); HSIL (green); early stage IC [FIGO Stage I] (blue); and advanced IC [FIGO Stage II-IV] (cyan). Thermograms show a progressive shift towards higher denaturation temperatures with increasing disease burden. Difference plots of clinical group thermograms compared to the control group (Panel C) show negative difference peaks ∼62°C and increasing shift and magnitude of higher temperature positive difference peaks. These are hypothesized to reflect the interaction of disease specific components with abundant plasma proteins, principally albumin, with resultant thermal stabilization and alteration of plasma thermogram profiles.
Figure 2.
Box charts showing thermogram shape and feature parameters for each clinical group.
Trends in thermogram parameters are observed with increasing disease burden from healthy controls (black); LSIL (red); HSIL (green); early stage IC [FIGO Stage I] (blue); and advanced IC [FIGO Stage II-IV] (cyan). Increased width with concomitant decreased height reflects the change in profile shape with disease progression seen in Figure 1A. TFM, the first moment temperature corresponding to the geometric center of the thermogram, provided a measure of this shape redistribution. TFM proved superior to Tmax, the temperature of the peak maximum, as a discriminatory metric for advanced IC where large distribution of Tmax values was correlated with significant variability in the heights of the major profile peaks. Profile width and the ratio of the major transition amplitudes, Cpex (Peak 1) and Cpex (Peak 2), provided the best metrics for discrimination of clinical status. Summary of statistical analyses of these parameters is shown by Tables 1 and 2. In each box chart the median value is indicated by the horizontal line within the box while the 25th and 75th percentiles are indicated by the lower and upper box edge, respectively. The mean value is indicated by the square within the box. The upper and lower “whiskers” define the 95th and 5th percentiles, respectively. The 99th and 1st percentiles are shown by the crossed symbols and the horizontal lines denoted the minimum and maximum of the data set.
Table 1.
Thermogram shape and feature parameters for each clinical group.
Table 2.
Statistical comparison of differences in thermogram parameters between clinical groups.
Figure 3.
Discriminate principal components analysis (dPCA) of MALDI-TOF MS peptidomic data.
MALDI-TOF MS spectra were aligned and binned using Markerview software version 1.2 (Applied Biosystems, Framingham, MA) and analyzed using discriminant Principal Component Analysis (dPCA). The top two principal components from the dPCA analysis of MALDI-TOF MS data for free urine peptides sort cervical cancer (asterisks), CIN 2 (triangles) and control cervix (circles) urine samples into discriminate groups.
Figure 4.
Discriminate principal components analysis (dPCA) of MALDI-TOF MS peptidomic data.
MALDI-TOF MS spectra were aligned and binned using Markerview software version 1.2 (Applied Biosystems, Framingham, MA) and analyzed using discriminant Principal Component Analysis (dPCA). The top two principal components from the dPCA analysis of MALDI-TOF MS data for peptides released following precipitation of plasma proteins by addition of acetonitrile/acetic acid. (FX2; Fraction 2) sort cervical cancer (asterisks), CIN 2 (triangles) and control cervix (circles) plasma samples into discriminate groups.
Table 3.
Differentially abundant plasma and urine peptides (900–3000 m/z) correlating with cervical cancer, CIN 2 or control samples.