ABSTRACT
Objective · To investigate the effect of a new type of allene compound, 1-phenylpropadienyl phosphine oxide (PHPO), on proliferation and apoptosis of lung cancer cell line A549. Methods · A549 cells were treated with different concentrations of PHPO. The effects of PHPO on cell proliferation, apoptosis and cell cycle were detected by CCK-8 and flow cytometry assay. Wound healing test was used to measure the migration ability of A549 cells. Real-time PCR was used to detect the expression of apoptosis and cell cycle related gene. The expression of proteins in MAPK pathway was assayed by the Western blotting. The nude mice xenograft model of human lung cancer A549 cells was established. After tumor formation, PHPO was injected daily for treatment, and the tumor size was observed. Results · Compared to the control group, PHPO significantly inhibited the cell viability of A549 cells and induced apoptosis of them, and the IC50 value of 24 h is 44.23 μmol/L. PHPO blocked the cell cycle in the G1 phase significantly. The migration capacity of PHPO-treated cells was decreased. The mRNA levels of Bax and P21 were up-regulated in PHPO-treated group, and the mRNA lever of Bcl-2 was down-regulated (P<0.05). PHPO increased the phosphorylation levels of p38, ERK and JNK. Injection of PHPO could significantly inhibit the growth of tumor in the xenograft model compared to the control group (P<0.05). Conclusion · PHPO can induce the apoptosis and inhibit the proliferation of A549 cells, block the cell cycle in the G1 phase and decrease the migration ability of A549 cells significantly. The mechanism may be related to the activation of MAPK signaling pathway by PHPO and the increase of phosphorylation of p38, ERK and JNK.
ABSTRACT
Objective · To investigate the effect of a new type of allene compound, 1-phenylpropadienyl phosphine oxide (PHPO), on proliferation and apoptosis of lung cancer cell line A549. Methods · A549 cells were treated with different concentrations of PHPO. The effects of PHPO on cell proliferation, apoptosis and cell cycle were detected by CCK-8 and flow cytometry assay. Wound healing test was used to measure the migration ability of A549 cells. Real-time PCR was used to detect the expression of apoptosis and cell cycle related gene. The expression of proteins in MAPK pathway was assayed by the Western blotting. The nude mice xenograft model of human lung cancer A549 cells was established. After tumor formation, PHPO was injected daily for treatment, and the tumor size was observed. Results · Compared to the control group, PHPO significantly inhibited the cell viability of A549 cells and induced apoptosis of them, and the IC50 value of 24 h is 44.23 μmol/L. PHPO blocked the cell cycle in the G1 phase significantly. The migration capacity of PHPO-treated cells was decreased. The mRNA levels of Bax and P21 were up-regulated in PHPO-treated group, and the mRNA lever of Bcl-2 was down-regulated (P<0.05). PHPO increased the phosphorylation levels of p38, ERK and JNK. Injection of PHPO could significantly inhibit the growth of tumor in the xenograft model compared to the control group (P<0.05). Conclusion · PHPO can induce the apoptosis and inhibit the proliferation of A549 cells, block the cell cycle in the G1 phase and decrease the migration ability of A549 cells significantly. The mechanism may be related to the activation of MAPK signaling pathway by PHPO and the increase of phosphorylation of p38, ERK and JNK.
ABSTRACT
<p><b>BACKGROUND</b>Technetium-99m or (99m)Tc is widely used for labeling peptide in nuclear medicine. Somatostatin and its analog can inhibit tumor cell growth after binding with its receptor. This research was to study the preclinical effect of a new (99m)Tc-6-hydrazinopyridine-3-carboxylic acid (HYNIC)-depreotide, indirect (99m)Tc labeling of depreotide using HYNIC as a bifunctional chelator.</p><p><b>METHODS</b>The cyclopeptide, cyclo-[(N-Me) Phe-Tyr-D-Trp-Lys-Val-Hcy], the linear peptide, and [ClCH(2)-CO×b-Dap-Lys- Cys-Lys×amide] were synthesized by Fmoc solid-phase synthesis. The cyclopeptide and the linear peptide were linked by liquid-phase synthesis. The product depreotide was isolated and purified by high performance liquid chromatography and was confirmed by mass spectrography. Depreotide was labeled with (99m)Tc through a direct labeling method, using HYNIC as a bifunctional chelator. Paper chromatography method was used to calculate the labeling rate, and through the comparative analysis selected the best mark conditions. The new (99m)Tc-HYNIC-depreotide was tested by high-performance liquid chromatography (HPLC). The internalization and externalization rates of the new (99m)Tc-HYNIC-depreotide were studied in A549 cells. Furthermore, biodistribution of the radiopeptide was studied in nude mice, bearing tumors from human lung carcinoma cells SPC-A1.</p><p><b>RESULTS</b>The molecular of synthesize depreotide was 1358, and the purity of it was 95.29%. The labeling efficiency of (99m)Tc-HYNIC-depreotide was highest at pH 6.0 and 15°C, about (70.95 ± 0.84)%. The labeling rate of the new (99m)Tc-HYNIC-depreotide rose to a peak of (20.75 ± 0.48)% at 60 minutes in A549 cells at 37°C and decreased slightly later, while it elevated gradually during the time course at 4°C and 25°C. The internalization rate of the new (99m)Tc-HYNIC-depreotide at 37°C increased gradually and reached the peak of 84.4% in 120 minutes, while the externalization rate of the new (99m)Tc-HYNIC-depreotide was always less than 20%. In mice bearing the experimental SPC-A1 tumor, the new (99m)Tc-HYNIC-depreotide demonstrated a high tumor uptake of (4.05 ± 0.04)% ID/g at 1.5 hpi and remained high ((2.51 ± 0.06)% ID/g) at 4 hpi. The tumor-to-lung activity concentration ratio (T/Lu) was very high for the new (99m)Tc-HYNIC-depreotide at all time points. So did the tumor-to-muscle activity (T/Mu) and tumor-to-blood activity concentration ratios (T/Bl).</p><p><b>CONCLUSION</b>The findings suggested that the new (99m)Tc-HYNIC-depreotide might be a promising candidate radiopharmaceutical for imaging somatostatin receptor positive lung cancer.</p>