[Reversion Mechanism Study of PESV to Multidrug Resistance at Leukemia Stem Cell Level].

OBJECTIVE: To explore the effect of peptide extract from scorpion venom (PESV) to multidrug resistance (MDR) of leukemic stem cell (LSC) in vivo. METHODS: K562/A02 cells were cultured and collected in the logarithmic phase. K562/A02 stem cells were screened using immunomagnetic beads for reserve. K562/A02 LSC was injected to 5 of 40 BABL/c nude mice for preparing subcutaneous tumor. The rest 35 nude mice were then randomly divided into 7 groups, i.e., the normal control group, the model group, the Adriamycin (ADM) group, the PESV group, the ADM +high dose PESV group, the ADM + middle dose PESV group, the ADM +low dose PESV group, 5 in each group. Tumor tissue was embedded in all groups except the normal control group. One milliliter normal saline was peritoneally injected to mice in the model group after modeling, once per day. ADM 0. 05 mg was peritoneally injected to mice in the ADM group, once per other day. PESV 2 µg was peritoneally injected to mice in the PESV group, once per day. Mice in 3 ADM + PESV groups were peritoneally injected with ADM 0. 05 mg (once per other day) plus PESV (5, 2, and 1 µg respectively, once per day). All medication lasted for 14 days. P-glycoprotein (P-gp) was detected using flow cytometry. Breast cancer resistance protein (BCRP) and mRNA expression of multidrug resistance 1 (MDR1) were measured using RT-PCR. Aldehyde dehydrogenase 1 (ALDH1) was detected using immunohistochemistry. Phosphoinositide 3-kinase (PI3K) was detected using Western blot. NF-κB content was detected using ELISA. RESULTS: CD34 + CD38-ratio was 31.5% and IC50 was (60.33 ± 10. 68) µg/mL before K562/A02 cells were screened with immunomagnetic beads, while they were 92. 8% and (58. 33 ±9. 72) µg/mL after screen. The tumor formation rate was 100% in modeling mice. Compared with the model group, no statistical difference of each index occurred in the ADM group (P <0. 05). There was statistical difference in BCRP, MDR1 mRNA, or NF-κB factor between the model group and the PESV group (P <0. 05). The expression level of P-gp obviously decreased and the protein expression of P13K was down-regulated in 3 ADM + PESV groups (P <0. 05); mRNA expression of BCRP decreased and mRNA ex- pression of MDR1 obviously increased in the ADM + high dose PESV group and the ADM + middle dose PESV group, with statistical difference (P <0. 05). Protein expression of P13K was down-regulated in the ADM+ high dose PESV group, with statistical difference (P <0. 05). P-gp value, BCRP mRNA expression, MDR1 mRNA expression, PI3K, and NF-κB factor were all obviously down-regulated in the ADM +high dose PESV group, as compared with the ADM group and the PESV group respectively (P <0. 05). There was no statistical difference in ALDH1 positive rate among all groups (P >0. 05). Conclusion PESV combined ADM could down-regulate expression levels of P-gp, BCRP, MDR1, P13K, and NF-κB, strengthen the sensitivity of K562/A02 LSC to ADM in vivo, and reverse MDR of LSC.

Yi-qi-yang-yin-tang increases the sensitivity of KG1a leukemia stem cells to daunorubicin by promoting cell cycle progression and regulating the expression of PTEN, TOPOII and mTOR.

The present study aimed to investigate the effects of serum containing a combination of yi-qi-yang-yin-tang (YQYYT) and daunorubicin (DNR) on multidrug resistance in KG1a leukemia stem cells (LSCs). The effects of YQYYT and DNR on proliferation, cell cycle progression and the expression of phosphatase and tensin homolog (PTEN), topoisomerase II (Topo II) and mechanistic target of rapamycin (mTOR) in KG1a cells were investigated in vitro using cell counting kit-8 assay, flow cytometry, reverse transcription-quantitative polymerase chain reaction and western blotting, respectively. It was revealed that YQYYT-containing serum did not affect proliferation of KG1a cells compared with the blank group. Furthermore, there were no significant differences on the inhibition of proliferation among different groups at various concentrations of YQYYT. Treatment with YQYYT-containing serum (volume, 20 and 40 µl) and DNR was able to significantly inhibit the proliferation of KG1a cells compared with the blank group. The inhibition rate in the treatment group with YQYYT-containing serum (40 µl) and DNR for 48 h (72.5%) was higher compared with treatment for 24 h (60.4%, P<0.01). Treatment with YQYYT-containing serum was able to promote G0 phase of KG1a cells into cell cycle in a dose- and time-dependent manner, and significantly upregulated the mRNA expression of PTEN and Topo II, but did not affect mTOR expression compared with the blank group. Treatment with serum containing YQYYT alone did not directly affect the proliferation of KG1a cells, but when the cells were treated with a combination of YQYYT-containing serum and DNR, the proliferation of KG1a cells was significantly inhibited in a dose- and time-dependent manner. Furthermore, treatment with YQYYT-containing serum was able to promote cell cycle progression of KG1a cells in the G0 phase and upregulate the expression of the negative regulatory genes PTEN and Topo II. These results indicated the potential of YQYYT to reverse multidrug resistance in LSCs.

Prevalence and genotype distribution of human papillomavirus among Hakka women in China.

BACKGROUND: Human papillomavirus (HPV) infection is the primary risk factor for cervical cancer. HPV genotypes are associated with varying degrees of pathogenicity. To better formulate strategies for cervical cancer prevention, we investigated the population-specific distribution of HPV genotypes, including those with high carcinogenicity. METHODS: From January to December 2012, a cervical cancer-screening program for HPV infection in Hakka women of Heyuan City Guangdong province was conducted. Of 736,000 women residents, 8,284 volunteers were recruited. The cytology specimens of 107 women were not adequate and excluded. Thus, 8,177 women submitted to polymerase chain reaction (PCR) sequencing of 16 HPV genotypes via MassARRAY spectrometry. RESULTS: Risk stratification based on genotypes indicated that the prevalence of overall, high-risk, and low-risk HPV infections was 12.27%, 14.20%, and 0.79%, respectively. Of the 1,003 women positively infected, 82.75% were infected with a single HPV type; 17.25% were infected with ≥2 types. Analysis revealed a U-shaped curve in HPV prevalence that correlated with age group, with peaks at ages 18-24 y (22.03%) and 60-65 y (25%). The most frequently detected HPV genotype was HPV-52 (26.81%), and then HPV-16 (17.54%), HPV-58 (14.25%), HPV-18 (10.16%), HPV-68 (8.27%), HPV-39 (5.68%), and HPV-51 (5.38%). CONCLUSIONS: HPV-52 is the most prevalent genotype infecting Hakka women. Therefore, vaccination against HPV-52 is imperative. The prevalence of HPV infection is highest in the younger (18-24 y) and older (60-65 y) age groups, indicating that screening for HPV in Hakka women should be performed early and maintained in the elderly.