Polyphyllin VII Promotes Apoptosis in Breast Cancer by Inhibiting MAPK/ERK Signaling Pathway through Downregulation of SOS1.

Polyphyllin VII is a biologically active herbal monomer extracted from the traditional Chinese herbal medicine Chonglou. Many studies have demonstrated the anticancer activity of polyphyllin VII against various types of cancers, such as colon, liver, and lung cancer, but its effect on breast cancer has not been elucidated. In this study, we demonstrate that polyphyllin VII inhibited proliferation, increased production of intracellular reactive oxygen species, and decreased mitochondrial membrane potential in breast cancer cells. Notably, polyphyllin VII also induced apoptosis via the mitochondrial pathway. Transcriptome sequencing was used to analyze the targets of PPVII in regulating breast cancer cells. Mechanistic studies showed that polyphyllin VII downregulated Son of Sevenless1 (SOS1) and inhibited the MAPK/ERK pathway. Furthermore, PPVII exerted strong antitumor effects in vivo in nude mice injected with breast cancer cells. Our results suggest that PPVII may promote apoptosis through regulating the SOS1/MAPK/ERK pathway, making it a possible candidate target for the treatment of breast cancer.

Pimozide inhibits the growth of breast cancer cells by alleviating the Warburg effect through the P53 signaling pathway.

The Warburg effect is a promising target for the diagnosis and treatment of cancer, referring to the ability of cancer cells to generate energy through high levels of glycolysis even in the presence of oxygen, allowing them to grow and proliferate rapidly. The antipsychotic Pimozide has strong anti-breast cancer effects both in vivo and in vitro, whether Pimozide has an inhibitory effect on aerobic glycolysis has not been elucidated. In this study, Pimozide inhibited the Warburg effect of breast cancer cells by hindering glucose uptake, ATP level and lactate production; reducing the extracellular acidification rate (ECAR); suppressing the expression of PKM2, a rate-limiting enzyme in glycolysis. Intriguingly, Pimozide was significantly involved in reprogramming glucose metabolism in breast cancer cells through a p53-dependent manner. Mechanistic studies demonstrated Pimozide increased the expression of p53 through inhibition of the PI3K/Akt/MDM2 signaling pathway, which in turn downregulated the expression of PKM2. In sum, our results suggest that Pimozide mediates the p53 signaling pathway through PI3K/AKT/MDM2 to inhibit the Warburg effect and breast cancer growth, and it may be a potential aerobic glycolysis inhibitor for the treatment of breast cancer.

High CCR5 density on central memory CD4+ T cells in acute HIV-1 infection is mostly associated with rapid disease progression.

CD4+ central memory T cells play a critical role in the pathogenesis of simian immunodeficiency virus disease, and the CCR5 density on the surface of CD4 T cells is an important factor in human immunodeficiency virus (HIV)-1 disease progression. We hypothesized that quantifying central memory cells and CCR5 expression in the early stages of HIV-infection could provide useful prognostic information. We enrolled two different groups of acute HIV-infected subjects. One group progressed to CD4 T cell numbers below 250 cells/µl within 2 years (CD4 Low group), while the other group maintained CD4 cell counts above 450 cells/µl over 2 years (CD4 High group). We compared the CCR5 levels and percentage of CD4 subsets between the two groups during the 1st year of HIV infection. We found no differences between the two groups regarding the percentage of naïve, central memory and effector memory subsets of CD4 cells during the 1st year of HIV-1 infection. CCR5 levels on CD4+ CM subset was higher in the CD4 Low group compared with the CD4 High group during the 1st year of HIV-1 infection. High CCR5 levels on CD4 central memory cells in acute HIV infection are mostly associated with rapid disease progression. Our data suggest that low CCR5 expression on CD4 central memory cells protects CD4 cells from direct virus infection and favors the preservation of CD4(+) T cell homeostasis.

[Influence of HLA-A, B loci carrying Bw4 motif on HIV CD4 T cell count and viral load].

OBJECTIVE: To analyze the influence of Bw4 motif carried by HLA-A, B loci on CD4 T cell count and viral load of primary HIV infectors. METHODS: The technique of SSP-PCR was employed to detect the HLA-A, B allele typing in 95 HIV infectors. And the roles of Bw4 motif carried by HLA-A, B loci on CD4 T cell count and viral load were analyzed. RESULTS: (1) The population frequency of HLA-A, B loci carrying Bw4 motif was respectively 32.6% (31/95) and 60.0% (57/95). The population frequency of Bw4/4, Bw4/6, Bw6/6 located on HLA-B was 21.1% (20/95), 38.9% (37/95) and 40.0% (38/95) respectively. (2) Compared with those with CD4 T cell count less than 500/µl, more Bw4 motifs were expressed on HLA-A, B loci of patients with CD4 cell count more than 500/µl (mean rank, 56.7 vs 41.6, U = 749.5, P < 0.01). Moreover, the fewest infectors were those with HLA-A, B carrying 3 Bw4 motifs and CD4 T cell count fewer than 500/µl (1 case). And secondly were those with HLA-A, B carrying 0 or 3 Bw4 motif and CD4 cell count more than 500/µl (7 cases, χ(2) = 12.6, P < 0.01). (3) The infectors with HLA-A, B loci carrying 3 Bw4 motifs had more CD4 T cell count (median: 651/µl) and less viral load(lg median: 3.43)than those with HLA-A, B carrying 0 or 1 Bw4 motif (430 and 425/µl, 4.48 and 4.40). And the difference was significant (all P < 0.05). However, the CD4 cell count and viral load between the patients with HLA-A, B carrying 2 Bw4 motifs and 3 Bw4 motifs were insignificantly different (P > 0.05). (4) Irrespective of Bw4 motif on HLA-A locus, the infectors HLA-B carrying Bw4/4 homozygote had more CD4 cell count (median: 538/µl) and less viral load (lg median: 3.53) than those carrying Bw4/6 heterozygote or Bw6/6 homozygote (433/µl and 427/µl, 4.29 and 4.48, all P < 0.05). However, irrespective of Bw4 motif on HLA-B, the CD4 cell count and viral load were insignificantly different between the infectors HLA-A carrying Bw4 motif and non-Bw4 motif. CONCLUSION: Bw4 motifs can increase the CD4 cell count and decrease the viral load of patients with primary HIV infection. Maybe Bw4/4 homozygote on HLA-B plays a role of delaying the disease progression.

[Study on T cell subsets in HIV/AIDS patients].

OBJECTIVE: Analyze Naive and Mermory T cell subsets in HIV/AIDS patients and investigate their relationship with disease development. METHODS: T cell subsets from 15 normal control subjects, 79 HIV/ AIDS patients were detected by FCM. RESULTS: With diesase progression, CD4+ Naive cell counts and ratio was both decreased obviously (P < 0.001); CD4+ Tcm cell counts was significantly decreased (P < 0.001), CD4+ Tcm cell ratio was obviously higher (P = 0.002); CD4 TEM cell ratio was obviously increased( P < 0.001); CD8+ T Naive cell counts and ratio was also decreased obviously (P < 0.05); CD8+ T(CM), T(EM), T(EMRA) are not significantly different. CONCLUSIONS: The peripheral lymphocyte subsets in HIV/AIDS patients changed obviously. The counts of naive T cell decreased, while the proportion of memory T cell increased significantly. It will help to understand pathogenesis of HIV.

[Expression and purification of TAT-HBX-EGFP fusion protein and its transmembrane distribution in mouse].

OBJECTIVE: To highly express TAT-HBX-EGFP fusion protein and study its distribution in mouse liver. METHODS: TAT-HBX-EGFP recombinant vector was constructed and fusion protein was induced by IPTG and expression in BL21; fusion protein was purified by Ni-NTA argarose, then injected into the peritoneal cavity of the mice. Distribution of fusion protein was observed by immunofluorescence. RESULTS: TAT-HBX-EGFP was highly expression in E. coli; HBX could be induced into mouse liver by TAT. CONCLUSION: HBX protein could be induced into mouse liver by TAT induced peptide.

[E2F1 upregulates endogenous XRCC1 expression].

OBJECTIVE: To investigate the regulatory effect and significance of transcription factor E2F1 on X-ray repair cross2 complementing 1 (XRCC1). METHODS: Saos2 cells were transfected with the E2F1 expression vectors (tet-E2F1) and mutated E2F1 expression vectors (tet-132E). XRCC1 promotor luciferase reporter vector was constructed and transfected into Saos2 cells together with E2F1, E2F2, E2F3 and E2F4 expression vectors at different amount. The cells were collected 36 hours post-transfection for luciferase assays and absorbance was read at 570 nm. RESULTS: Cotransfection of increasing amounts of E2F1 expression vector with the XRCC1 promoter-luciferase reporter caused a dose-dependent increase in luciferase activation. In contrast, DNA binding incompetent E2F1 (132E) could not activate the XRCC1 promoter-luciferase reporter. CONCLUSION: E2F1 could upregulate endogenous XRCC1 expression and stimulate the XRCC1 promoter.