SLC7A11, a potential immunotherapeutic target in lung adenocarcinoma.

SLC7A11 has significant translational value in cancer treatment. However, there are few studies on whether SLC7A11 affects the immune status of lung adenocarcinoma (LUAD). Information on SLC7A11 expression and its impact on prognosis was obtained from the cancer genome atlas and gene expression omnibus databases. The differentially expressed genes (DEGs) were analysed by GO and KEGG. GSEA enrichment analysis was performed in the SLC7A11-high and SLC7A11-low groups. The relationship between SLC7A11 and tumour immunity, immune checkpoints, and immune cell infiltration was studied using R language. We analysed the correlation between SLC7A11 and chemotactic factors (CFs) and chemokine receptors using the TISIDB database. SLC7A11 is overexpressed in many tumours, including LUAD. The 5-year overall survival of patients in the SLC7A11-high group was lower than in the SLC7A11-low group. KEGG analysis found that the DEGs were enriched in ferroptosis signaling pathways. GSEA analysis found that the survival-related signaling pathways were enriched in the SLC7A11-low group. The SLC7A11-low group had higher immune scores and immune checkpoint expression. SLC7A11 was negatively correlated with many immune cells (CD8+ T cells, immature dendritic cells), CFs, chemokine receptors (such as CCL17/19/22/23, CXCL9/10/11/14, CCR4/6, CX3CR1, CXCR3) and MHCs (major histocompatibility complex). SLC7A11 may regulate tumour immunity and could be a potential therapeutic target for LUAD.

Clustering analysis and prognostic signature of lung adenocarcinoma based on the tumor microenvironment.

Because of immunotherapy failure in lung adenocarcinoma, we have tried to find new potential biomarkers for differentiating different tumor subtypes and predicting prognosis. We identified two subtypes based on tumor microenvironment-related genes in this study. We used seven methods to analyze the immune cell infiltration between subgroups. Further analysis of tumor mutation load and immune checkpoint expression among different subgroups was performed. The least absolute shrinkage and selection operator Cox regression was applied for further selection. The selected genes were used to construct a prognostic 14-gene signature for LUAD. Next, a survival analysis and time-dependent receiver operating characteristics were performed to verify and evaluate the model. Gene set enrichment analyses and immune analysis in risk groups was also performed. According to the expression of genes related to the tumor microenvironment, lung adenocarcinoma can be divided into cold tumors and hot tumors. The signature we built was able to predict prognosis more accurately than previously known models. The signature-based tumor microenvironment provides further insight into the prediction of lung adenocarcinoma prognosis and may guide individualized treatment.

[Anti-Leukemia Effect and Mechanism of Oridonin on Imatinib-Sensitive and Imatinib-Resistant K562 Cells].

OBJECTIVE: To explore the molecular mechanism of resistance to imatinib in K562 cells(K562-R) and the anti-proliferative effect of oridonin (OR), as well as its mechanism in imatinib-sensitive and imatinib-resistant K562 cells (K562-S and K562-R cells). METHODS: The expression of p-Lyn in K562-S and K562-R cells were detected by Western blot. The anti-proliferative effect of OR in K562-S and K562-R cells was assayed by MTT, the morphological changes were examined with microscope, the cell apoptosis was detected by flow cytometry, the expressions of BCL-2 and Akt/mTOR signaling pathway were detected by Western blot. RESULTS: The over-expression of p-Lyn was detcected in K562-R cells, OR inhibited the proliferation of K562-S and K562-R cells and the value of IC50 was 4.23±1.30, 4.97±2.23 µmol/L, respectively. The apoptotic rate was obviously enhanced after OR treatment for 24 h, compared with control group. OR down-regulated the expression of p-Lyn, mTOR signaling pathway and BCL-2 protein. CONCLUSION: Over-expression of p-Lyn may be involved in the mechanism of resistance to imatinib. OR can inhibit the proliferation of K562-S and K562-R cells through down-regulating p-Lyn, inhibiting mTOR signaling pathway and down-regulating expression of BCL-2 protein.

Curcumin potentiates the anti-leukemia effects of imatinib by downregulation of the AKT/mTOR pathway and BCR/ABL gene expression in Ph+ acute lymphoblastic leukemia.

Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) is triggered by BCR/ABL and SRC family tyrosine kinases. They interact with each other and subsequently activate downstream growth-signaling pathways, including Raf/MEK/ERK, Akt/mTOR, and STAT5 pathways. Although imatinib is the standard treatment for Ph+ leukemia, response rate of Ph+ ALL to imatinib is low, relapse is frequent and quick. Studies have documented the potential anti-tumor activities of curcumin. However, whether curcumin can be used in the therapy for Ph+ ALL remains obscure. Here, we reported that curcumin induced apoptosis by inhibition of AKT/mTOR and ABL/STAT5 signaling, down-regulation of BCR/ABL expression, and induction of the BCL2/BAX imbalance. Curcumin exerted synergetic anti-leukemia effects with imatinib by inhibition of the imatinib-mediated overactivation of AKT/mTOR signaling and down-regulation of BCR/ABL gene expression. In primary samples from Ph+ ALL patients, curcumin inhibited cellular proliferation and down-regulated constitutive activation of growth-signaling pathways not only in newly diagnosed patients but also in imatinib-resistant patients. In Ph+ ALL mouse models, curcumin exhibited synergetic anti-leukemia effects with imatinib. These results demonstrated that curcumin might be a promising agent for Ph+ ALL patients.

[Effect of tanshinone II A on leukemia cell line K562].

OBJECTIVE: To determine the anti-proliferative effect of Tanshinone II A (TAT) on leukemia K562 cell line and its mechanism. METHODS: The proliferation of K562 cell line was detected by MTT assay. The morphological changes of the cells were examined with light microscope. The cell apoptosis was detected by flow cytometry. The expressions of BCL-2, BAX and m-TOR signaling pathway were examined by Western blot assay. RESULTS: TAT inhibited the proliferation of K562 cell line, with a value of IC50 (7.75 +/- 2.47) micromol/L after treatment for 96 h. Significant morphological changes were found after incubation of the cells for 24 h. The apoptotic rate accelerated after TAT treatment for 24 h compared with the controls. TAT down-regulated the expression of mTOR signaling pathway and BCL-2 protein, and up-regulated proapoptotic protein BAX. CONCLUSION: TAT can inhibit the proliferation of K562 cells through down-regulating mTOR signaling pathway, inducing apoptosis.

Curcumin induces apoptosis via simultaneously targeting AKT/mTOR and RAF/MEK/ERK survival signaling pathways in human leukemia THP-1 cells.

BACKGROUND: Curcumin is a multi-targeted anti-cancer agent. However, there are few studies on its anti-leukemia activity in human acute monocytic leukemia. Here, we study the effect and mechanisms of curcumin on acute monocytic leukemia. METHODS: The acute monocytic leukemia cell line THP-1 was used as in vitro cell model to explore the anti-leukemia effects and mechanisms of curcumin. Cell proliferation was measured by MTT assay, cell apoptosis bodies were observed using a light microscope, cell apoptosis rate was evaluated by flow cytometry, and the expression alterations of growth-sinaling proteins were detected by Western blotting. RESULTS: Curcumin inhibited cell proliferation and induced cell apoptosis in time- and dose- dependent manner in THP-1 cells. Curcumin significantly inhibited the activations of AKT/mTOR and RAF/MEK/ERK signaling pathways simultaneously. CONCLUSION: This study demonstrates that curcumin inhibits proliferation and induces apoptosis in THP-1 cells via inhibiting the activations of AKT/mTOR and RAF/MEK/ERK signaling pathways simultaneously. Our data suggest that curcumin is a promising anti-tumor agent in acute monocytic leukemia.

[Anti-leukemia effect of oridonin on T-cell acute lymphoblastic leukemia].

OBJECTIVE: To investigate the antileukemia effect of oridonin on T-cell acute lymphoblastic leukemia cell line CEM. METHODS: Human T-cell acute lymphoblastic leukemia cell line CEM was cultured in vitro. The 50% inhibition concentration (IC50) of oridonin against CEM cells was examined using modified MTT assay. The cellular morphologic changes were observed using a light microscope. The percent of apoptosis of CEM cells after drug treatment was evaluated by flow cytometric analysis. The active levels of AKT/mTOR, RAF/MEK/ ERK, STAT5 signaling pathways and the expression levels of Bcl-2 and BAX were examined by Western blot. RESULTS: Oridonin inhibited the growth of CEM cells in time- and dose dependent manner and the ICs0 of oridonin was (7. 37± 1. 99) µmol/L after 72 h treatment. The cellular membrane of CEM cells treated with oridonin became unsharp, some of them disintegrated. Oridonin induced apoptosis in CEM cells and the percent of apoptosis rate after 0, 5, 7.5, 10 µmol/L oridonin treatment for 24 h were (4. 8±2. 11)%, (19.03±12.54)% ,(40.27± 3.31) / and (57. 23 ± 6. 69)% respectively. Oridonin inhibited activation of mTOR, P70S6, 4EBP1, RAF. ERK and STAT5 signaling protein, which were constitutively activated in CEM cells, however, oridonin had no inhibitory effect on AKT kinase. Oridonin down-regulated the level of anti apoptotic protein Bcl-2 and up-regulated the expression of pro-apoptotic protein Bax. CONCLUSION: Oridonin exerted antileukemia effect in CEM cells by inhibiting the activation of mTOR/P70/4EBP1, RAF/ERK and STATS signaling pathways, down-regulating the expression of Bel-2 and up-regulating the expression of BAX.

[Multidrug resistant gene MDR1 contributes to development of imatinib-resistance in Ph (+) acute lymphoblastic leukemia cell line SUP-BS15RI].

OBJECTIVE: To investigate the contribution of multidrug-resistant gene MDR1 to development of imatinib-resistance in Ph(+) acute lymphoblastic leukemia cell line SUP-B15/RI. METHODS: RT-PCR was used to examine MDR1 mRNA levels, cytotoxic effects of imatinib (IM), daunorubicin (DNR), vincristine (VCR), etoposide (VP-16) and the synergetic antiproliferation with P-gp inhibitor verapamil on sensitive SUP-B15 and SUP-B15/RI cell lines were detected by the MTT assay. The P-gp function was measured by flow cytometry. RESULTS: Increased expression of MDR1 gene in SUP-B15/RI than that of SUP-B15 cell line (P < 0.05) was observed when detected with RT-PCR. The IC50 values of SUP-B15/RI cell line inhibited by IM, DNR, VCR, VP-16 for 72 hours was higher than that of SUP-B15 (P < 0.05) and the resistant factor (RF) was (20.52 +/- 2.34), (10.33 +/- 1.88), (9.78 +/- 1.27), (3.84 +/- 0.69) respectively. The IC50 values of IM, DNR, VCR, VP-16 combined with P-gp inhibitor verapamil were decreased in SUP-B15/RI cells (P < 0.05), reversal of drug resistance was (1.44 +/- 0.43), (3.20 +/- 0.17), (1.44 +/- 0.12), (1.33 +/- 0.14) respectively. The activity of P-gp in SUP-B15/RI measured by flow cytometry was higher than that of P-gp in SUP-B15/RI cell line. CONCLUSION: The overexpression of MDR1 mRNA and higher activity of P-gp is partially responsible for acquiring of imatinib resistance in SUP-B15/RI cell line. P-gp inhibitor verapamail can partially restored the sensitivity of the SUP-B15/RI cell line to anticancer agents.

[Anti-leukemia effect of oridonin on Ph(+) acute lymphoblastic leukemia cell SUP-B15].

OBJECTIVE: To investigate the anti-leukemia effect of oridonin on Ph(+) acute lymphoblastic leukemia (ALL) cell line SUP-B15. METHODS: Human Ph(+) ALL cell line was cultured in vitro. The 50% inhibition concentration (IC(50)) of oridonin against SUP-B15 cell line was examined using modified MTT assay. The cellular morphologic changes were observed using a light microscope. The percent of apoptosis of SUP-B15 cell line after drug treatment was evaluated by flow cytometric analysis. The active levels of ABL kinase and its downstream Akt/mTOR, Raf/MEK/ERK, STAT5 signaling pathways and the expression levels of Bcl-2 and BAX were examined by Western blot. RESULTS: Oridonin inhibited the growth of SUP-B15 cell line in both time- and dose-dependent manner with the IC(50) of oridonin as (7.08 ± 1.21) µmol/L after 72 h treatment. The cellular membrane of SUP-B15 cell line treated with oridonin became unsharp, some of them disintegrated. Oridonin induced apoptosis in SUP-B15 cell line with the apoptosis rates following 0, 5, 10 µmol/L oridonin treatment for 24 h were (6.67 ± 0.83)%, (18.30 ± 1.79)% and (37.63 ± 7.12)%, respectively. Oridonin inhibited activation of ABL kinase and its downstream Akt/mTOR, Raf/MEK/ERK and STAT5 signaling pathways, which were constitutively activated in SUP-B15 cell line, down-regulated the level of anti- apoptotic protein Bcl-2 and up-regulated the expression of pro-apoptotic protein Bax. CONCLUSION: Oridonin exerted anti-leukemia effect in Ph(+)ALL cell line SUP-B15 by inhibiting the activation of ABL kinase and its downstream Akt/mTOR, Raf/MEK/ERK and STAT5 signaling pathways, down-regulating the expression of Bcl-2 and up-regulating the expression of BAX.

[The effect of knockdown of transcription factor SCL/TAL-1 gene on the erythroid differentiation in EPO-induced K562 cell line].

OBJECTIVE: To investigate the role of transcript factor SCL/TAL-1 gene in the erythroid differentiation through the knockdown of SCL/TAL-1 mRNA by RNA interference. METHODS: The plasmid of pTRIP-dU3-RNAiTALh-EF1a-GFP with SCL/TAL1 shRNA was transfected into EPO-induced K562 cell line with erythroid differentiation via lentiviral vector system and the expression of SCL/TAL-1 mRNA decreased. The plasmid pTRIP-dU3- RNAiluc-EF1-GFP expressing EGFP gene was as control. The mRNA levels of SCL/TAL-1 and erythroid related RhD, GPA, CD47 in the cell lines were detected by RT-PCR, and erythroid antigen CD71, CD235a were examined by flow cytometry. RESULTS: (1) After 48 h of transfect, more than 95% of K562 cells were GFP positive, indicating the infection rate of the plasmids in the K562 cells more than 95%. (2) The results of RT-PCR showed SCL/TAL-1 mRNA expression in the K562 cell line of knockdown of SCL/TAL-1 was significantly lower than that in the control (P < 0.05). The mRNA levels of CD47 and RhD were also significantly lower, however, GPA decreased slightly in comparison with the control. (3) The expressions of CD71 and CD235a markedly reduced in the K562 cell line of knockdown of SCL/TAL-1 with positive rates as 10.4% and 76.5%, while the positive rates in the control as 94.3% and 83.6%. CONCLUSION: Our findings suggested that transcription factor SCL/TAL-1 might play an positive role in erythroid differentiation.

Oridonin in combination with imatinib exerts synergetic anti-leukemia effect in Ph+ acute lymphoblastic leukemia cells in vitro by inhibiting activation of LYN/mTOR signaling pathway.

Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) is triggered by constitutively activated BCR-ABL and SRC family tyrosine kinases.They account for the activations of multiple growth-signaling pathways, including Raf/MEK/ERK, Akt/mTOR and STAT5 pathways. The BCR-ABL tyrosine kinase inhibitor imatinib is the standard treatment for Ph+ leukemia and plays efficacious role in CML. However, imatinib has few inhibitory effects on SRC tyrosine kinase with response rate of Ph+ ALL lower and relapse more frequent and quicker compared with CML. Previous studies showed that oridonin inhibits proliferation and induces apoptosis in many tumor cells. However, the anticancer activity and mechanism of oridonin in Ph+ ALL is unknown. To investigate the anticancer activity of oridonin, we examined its role in constitutively activated Akt/mTOR, Raf/MEK/ERK, STAT5 and SRC pathway, mRNA level of bcr/abl gene, cell viability and apoptosis in Ph+ ALL SUP-B15 cells. Furthermore, we detected synergetic effect of oridonin plus imatinib. Our results showed that oridonin inhibiting activations of LYN (one of SRC family kinases) and ABL and their downstream Akt/mTOR, Raf/MEK/ERK and STAT5 pathways, downregulated Bcl-2 but upregulated Bax protein and then induced apoptosis in Ph+ ALL cells. Oridonin plus imatinib exerted synergetic effects by overcoming imatinib defect of upregulating Akt/mTOR and LYN signaling. Additionally, we examined the effect of oridonin on the signaling pathways in the primary specimens from Ph+ ALL patients. Our data showed that oridonin remarkably suppressed activations of Akt/mTOR, Raf/MEK and STAT5 pathway in these primary specimens and oridonin with imatinib exerted synergetic suppressive effects on mTOR, STAT5 and LYN signaling in one imatinib resistant patient specimen. Additional evaluation of oridonin as a potential therapeutic agent for Ph+ ALL seems warranted.

[Anti-tumor effect of tanshinone II A, tetrandrine, honokiol, curcumin, oridonin and paeonol on leukemia cell lines].

OBJECTIVE: To study the anti-tumor effect of tanshinon II A, tetrandrine, honokiol, curcumin, oridonin and paeonol on leukemia cell lines SUP-B15, K562, CEM, HL-60 and NB4. METHODS: To study the anti-tumor effect of tanshinone II A, tetrandrine, honokiol, curcumin, The leukemia cell lines were exposed to the six Chinese herbal components for 96 hours. The proliferative inhibitory effects were detected with MTT and described by IC50 value. RESULTS: Tanshinone II A inhibited the proliferations of SUP-B15, K562, CEM, HL-60 and NB4 cell lines, with HL-60 showing the least impact. Tetrandrine, honokiol, curcumin and oridonin inhibited the proliferations of SUP-B15, K562, CEM, HL-60 and NB4 cell lines and there was no significant difference between the cell lines. Paeonol did not have significant inhibitory effect on leukemia cell lines. CONCLUSION: Tetrandrine, honokiol, curcumin and oridonin inhibit the proliferation of five cell lines SUP-B15, K562, CEM, HL-60, NB4, and the effects are similar, which means that their anticancer effects are quite broad. Tanshinone II A has better anti-leukemia effects on SUP-B15, K562, CEM, NB4 than on HL-60. The effect of paeonol against leukemia cell lines is poor.

Antileukaemia effect of rapamycin alone or in combination with daunorubicin on Ph+ acute lymphoblastic leukaemia cell line.

The translocation (9;22) (q34;q11), known as the Philadelphia (Ph) chromosome and bcr-abl fusion gene, is the common cytogenetic abnormality and an unfavourable prognosis in adult acute lymphoblastic leukaemia (ALL). Although chemotherapeutic treatment produced high rates of complete response in approximately 70%-80% of newly diagnosed Ph+ ALL, the onset of resistance and clinical relapse is rapid. Therefore, the efficacy of treatment in Ph+ ALL is still to be determined. In this study, we aimed to assess the antileukemic activity of rapamycin (RAPA) (Sigma-Aldrich Corporation, MO, USA), a mammalian target of rapamycin inhibitor, alone and in combination with daunorubicin (DNR) (Pharmacia & Upjohn Company, Germany) in a Ph+ acute lymphoblastic cell line SUP-B15 and a primary Ph+ ALL sample in vitro. Here, we demonstrated that 50 nmol/L of RAPA significantly intensified the inhibition induced by DNR on both Ph+ ALL cell line and a primary Ph+ ALL sample. Notably, we reported that the consequence of DNR treatment induced the over expression of the components of mammalian target of rapamycin signalling pathway, whereas RAPA effectively eliminated this deleterious side effect of DNR, which might enhance DNR's ability to kill drug-resistant cancer. The synergistic effect was also associated with the increase in autophagy, blockage of cell cycle progression in the G1 phase. Altogether, our results suggest that DNR in combination with RAPA is more effective in the treatment of Ph+ ALL compared with DNR alone.