Table 1. List of identification results for the proteins that were differentially expressed between the normal NG108-15 cells and the senescent NG108-15 cells.

Spot	Protein Descriptiona	Accession no.b	Theoretical Mr(kDa)/pI	Sequence Coveragec	Summary Scored	Protein Levele	p-valuef	Normal(mean±SD)g	Senescence(mean±SD)g
1	peptidylprolyl isomerase A	NP_032933	18.131/7.74	0.31	83	↑	<0.01	31342±523	51245±662
2	peroxiredoxin 1	NP_035164	22.390/8.26	0.63	184	↓	<0.01	16783±726	5722±357
3	glutathione S-transferase, mu 1	NP_034488	26.067/7.71	0.71	187	↓	<0.01	19886±548	9937±469
4	vimentin	CAA69019	51.590/4.96	0.57	267	↑	<0.01	5170±536	29865±418
5	glucose-regulated protein 78	NP_037215	72.473/5.07	0.37	239	↓	<0.01	82853±758	42305±477

^a. According to SWISS-PROT DE line.

^b. SWISS-PROT accession number.

^c. Ratio of matched peptides with total PMF peptides.

^d. Percent of identified sequence to the complete sequence of the known protein.

^e. The increased or decreased expression protein levels in the Senescent NG108-15 cells as compared to the Normal NG108-15 cells and (±) indicates identical spot intensity in the two gels.

^f. The p-value was statistically analyzed by student t-test analysis between Normal NG108-15 cells and NG108-15 cells.

^g. The quantity (mean ± SE) of each protein spot was calculated using 2-DE gels.