Establishment of Cas9 stably expressed human hepatocellular carcinoma and cholangiocarcinoma cell lines / 中华肿瘤杂志

Objective@#To facilitate using the CRISPR/Cas9 gene editing system in human liver and gallbladder cancer cells, we established Cas9 stably expressed human liver and gallbladder cancer cell lines, and validated the gene editing activity of Cas9.@*Methods@#Human liver cancer cell lines (Huh7, PLC/PRF/5, HepG2, Hep3b, SK-HEP-1 and Li-7), human cholangiocarcinoma cells (RBE) and human gallbladder cancer cells (GBC-SD) were infected with 3 Cas9-expressing lentivirus vectors (pLv-EF1α-Cas9-Flag-Neo, pLv-EF1α-Cas9-Flag-Puro, Cas9m1.1), respectively, and Cas9 stably expressed colonies were screened and selected. We extracted the genomic DNA and protein, validated the stable expression of Cas9 by using genomic polymerase chain reaction (PCR) and western blot. Three of cell lines were further infected with Lv-EF1α-mCherry. Then mCherry positive cells were sorted by flow cytometry and infected with designed guide RNA (gRNA) vectors which targeted mCherry gene. Subsequently the gene editing activity of Cas9 was detected by genomic PCR, fluorescence microscopic observation and flow cytometry analysis.@*Results@#One hundred Cas9-expressing human liver and gallbladder cancer cell lines were selected. Among them, 35 cell lines expressed Cas9-Neo, 25 expressed Cas9-puro, and 40 expressed mutant Cas9 (mCas9). We also established 3 cell lines with stable expression of mCherry (Huh7-mCas9-M, PLC/PRF/5-Cas9-M and SK-HEP-1-Cas9-M). The results of genomic PCR and sequencing showed that by lentiviral infection with 2 types of designed gRNA, the long fragment deletion of mCherry gene was found in these 3 cell lines. Moreover, mCherry-EGFP+ cells infected with 2 types of gRNA were observed by fluorescence microscope. The results of flow cytometry showed that mCherry-EGFP+ cells accounted from 0.3% to 93.6%.@*Conclusion@#We successfully establish 100 human liver and gallbladder cancer cell lines with stable expression of Cas9 protein and validate their activities of gene editing.

Faciliated primary culture and amplification of breast cancer cells and their biological properties / 基础医学与临床

Objective To efficiently builds up and expand breast cancer cells from cancer tissue and to identify their biological properties , provide abundant materials for research and personalized medicine .Methods Feeder cell layer and ROCK inhibitor Y-27632 were employed to faciliate the breast cancer cells;CCK-8 was used to determine the proliferation of the breast cancer cells; Cell cycle distribution was analyzed by flow cytometry; Histochemistry ( FH) assay to show the expression level of CK .The mRNA expression of HER-2, ER, PR and the breast cancer stem cell associated molecules (such as CD44, CD24, etc.) were detected by RT-PCR;STR assay was used for identifying verification of the cells .Results The use of feeder cells and Y-27632 facilitates rapid expand of the original breast cancer cells , and the cells have kept the original features of the tumor .Conclusions To use the method could obtain a large number of cells within a short time , which can promptly be used for the research of per-sonalized medicine .

Detection of six main species of viruses in human cell lines / 中华实验和临床病毒学杂志

Objective@#To clarify the virus hosting status of human cell lines.@*Methods@#The DNA of Epstein-Barr virus (EBV), Hepatitis B virus (HBV), Human pappilomavirus (HPV), Human immunodeficiency virus (HIV), Human T-cell leukemia virus (HTLV) in 135 human cell lines were checked using PCR, and HCV RNA sequences were checked by RT-PCR. The transmission electron microscopy (TEM) was used to examine the virus particles in cells. The high-risk genotypes of HPV were tested by PCR.@*Results@#By PCR assaying, among the 135 human cell lines, four cell lines(Daudi, Raji, EB-3, NCI-BL2009) harbored EBV DNA sequences; two(Hep3B, PLC/PRF/5) harbored HBV DNA sequences; seven (HeLa, HeLa 229, H1HeLa, HeLaS3, SiHa, Caski, CNE-2Z) harbored HPV DNA sequences, including two cell lines (SiHa, Caski) with HPV16, five cell lines(HeLa, HeLa 229, H1HeLa, HeLaS3, CNE-2Z) with HPV18; one cell line(HUT 102) harbored HTLV DNA sequences. No cell line harbored HCV RNA sequences and HIV DNA sequences. No viral particles were observed in the positive cell lines by TEM, but some viral inclusion bodies in certain cell lines.@*Conclusions@#The virus hosting status of human cell lines can be checked by PCR or RT-PCR. The viral DNA sequences were integrated in the cellular genome.

Establishment and validation of human cancer cell lines with stable Cas9 expression / 中华病理学杂志

Objective@#To establish human cancer cell strains with stable Cas9 expression, and to validate the gene editing activity of Cas9 for simple gene editing in future study.@*Methods@#Fifteen cancer cell lines of different tissue origins were infected with pLv-EF1α-Cas9-Flag-Neo or pLv-EF1α-Cas9-Flag-Puro by lentivirus and clone selection was employed to screen Cas9 stably expressed cancer cell lines. Afterward designed guide RNA vectors targeting TSC22 gene were transiently transfected into 3 of cell lines, and subsequently the gene editing activity of Cas9 was evaluated by genomic PCR, sequencing and Western blot.@*Results@#Sixty-nine human cancer cell strains with stable Cas9 expression from different cancers were established, and by transient transfection with designed guide RNA, long fragment deletion was detected in TSC22 gene.@*Conclusions@#Sixty-nine human cancer cell strains are successfully established with stable expression of Cas9 protein and gene editing activity. These cell strains may be employed in large-scale drug screening, screening of new drug targets and gene function investigation.

Enhanced growth inhibition by combined two pathway inhibitors on K-ras mutated non-small cell lung cancer cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To evaluate the effect of combined targeting of MEK and PI3K signaling pathways on K-ras mutated non-small cell lung cancer cell line A549 cells and the relevant mechanisms.</p><p><b>METHODS</b>A549 cells were treated with different concentrations of two inhibitors. Growth inhibition was determined by MTT assay. According to the results of MTT test, the cells were divided into four groups: the control group, PI3K inhibitor group (GDC-0941,0.5 and 5.0 µmol/L), combination group I (0.5 µmol/L AZD6244+0.5 µmol/L GDC-0941) and combination group II (5.0 µmol/L AZD6244+5.0 µmol/L GDC-0941). The cell cycle and apoptosis were analyzed by flow cytometry. The expression of proteins related to apoptosis was tested with Western blot.</p><p><b>RESULTS</b>Both GDC-0941 and AZD6244 inhibited the cell proliferation. The combination group II led to a stronger growth inhibition. The combination group I showed an antagonistic effect and combination group II showed an additive or synergistic effect. Compared with the control group, the combination group I led to reduced apoptotic rate [(20.70 ± 0.99)% vs. (18.65 ± 0.92 )%, P > 0.05]; Combination group II exhibited enhanced apoptotic rate [(37.85 ± 3.18)% vs. (52.27 ± 4.36)%, P < 0.01]. In addition, in the combination group II, more A549 cells were arrested in G0/G1 phase and decreased S phase (P < 0.01), due to the reduced expressions of CyclinD1 and Cyclin B1, the increased cleaved PARP and the diminished ratio of Bcl-2/Bax.</p><p><b>CONCLUSIONS</b>For single K-ras mutated NSCLC cell line A549 cells, combination of RAS/MEK/ERK and PI3K/AKT/mTOR inhibition showed synergistic effects depending on the drug doses. Double pathways targeted therapy may be beneficial for these patients.</p>