New insights into 4-amino-2-tri-fluoromethyl-phenyl ester inhibition of cell growth and migration in the A549 lung adenocarcinoma cell line

4-amino-2-trifluoromethyl-phenyl retinate alleviates lipopolysaccharide-induced acute myocardial injury through activation of the KLF4/p62 axis

Ferroptosis plays a pivotal role in the pathological process of sepsis-induced cardiomyopathy (SIC). All-trans retinoic acid (ATRA) enhances the host immune response to lipopolysaccharides (LPS). This study investigated the role of 4-amino-2-trifluoromethyl-phenyl retinate (ATPR), a derivative of ATRA, in myocardial injury caused by sepsis. Male C57BL/6 mice were intraperitoneally injected with LPS to establish a sepsis model. H9c2 cells were stimulated by LPS to establish an injury model. We observed that ATPR improved myocardial injury in mice, which was presented in terms of an increased glutathione (GSH) level and reduced production of malondialdehyde (MDA), as well as an increased number of mitochondrial cristae and maintenance of the mitochondrial membrane integrity. ATPR improved cardiac function in the LPS-injured mice. It inhibited the inflammatory response as evidenced by the decreasing mRNA levels of TNF-α and IL-6. The elevated protein expression levels of Nrf2, SLC7A11, GPX4, and FTH1 in mice and H9c2 cells showed that ATPR inhibited ferroptosis. Immunoprecipitation of LPS-stimulated H9c2 cells demonstrated that ATPR increased the interaction between p62 and Keap1. ATPR upregulated the KLF4 and p62 protein expression. However, the inhibition of Nrf2 by ML385 reduced the protective effect of ATPR in LPS-treated H9c2 cells. Furthermore, we used siRNA to knock down KLF4 in H9c2 cells and found that the KLF4 knockdown eliminated the inhibition of ferroptosis by ATPR in H9c2 cells. Therefore, ATPR alleviates LPS-induced myocardial injury by inhibiting ferroptosis via the KLF4/p62 axis.

Myosin light chain kinase is a potential target for hypopharyngeal cancer treatment

Hypopharyngeal cancer is squamous cell carcinoma (SCC) with the worst prognosis among the head and neck cancers. Overall, the 5-year survival rate remains poor although diagnostic imaging, radiation, chemotherapy, and surgical techniques have been improved. The mortality of patients with hypopharyngeal cancer is partly due to an increased likelihood of developing a second primary malignancy and metastasis. In this study, we found that MLCK expression, compared to healthy tissue, was up-regulated in hypopharyngeal tumor tissue. Of particular interest, a low 5-year survival rate was positively correlated with MLCK expression. We hypothesized that MLCK might be a target for hypopharyngeal cancer prognosis and treatment. In order to explore the function of MLCK in the development of cancer, we knockdown MLCK in hypopharyngeal cancer FaDu cells. The results showed that MLCK knockdown reduced the migration and invasion of FaDu cells. 4-amino-2-trifluoromethyl-phenyl retinate (ATPR) is the derivative of all-trans retinoic acid (ATRA), which was able to reduce both MLCK expression and activity in FaDu cells. ATPR induced FaDu cells apoptosis in a dose-dependent manner and also inhibited cell growth both in vivo and in vitro. Further experiments showed that overexpression of MLCK reduced ATPR induced-migration inhibition while increase of ATPR induced apoptosis, which suggested that MLCK was involved in ATPR's anti-cancer function. In conclusion, MLCK is a novel prognostic marker and therapeutic target for hypopharyngeal cancer. By targeting MLCK, ATPR exhibits its potential application in the treatment of this type of cancer.

LncRNA NR-104098 Inhibits AML Proliferation and Induces Differentiation Through Repressing EZH2 Transcription by Interacting With E2F1

Abundant evidence has illustrated that long non-coding RNA (lncRNA) plays a vital role in the regulation of tumor development and progression. Most lncRNAs have been proven to have biological and clinical significance in acute myeloid leukemia (AML), but further investigation remains necessary. In this study, we investigated lncRNA NR-104098 in AML and its specific mechanism. The microarray analysis was performed on NB4 cells. Based on the related analysis results, we identified that lncRNA NR-104098 is a suppressor gene that is significantly upregulated in AML cells. LncRNA NR-104098 could inhibit proliferation and induce differentiation in AML cells in vitro and also play main role in the mouse xenografts. Mechanically, it was confirmed that lncRNA NR-104098 may effectively inhibit EZH2 transcription by directly binding to E2F1 and recruiting E2F1 to the EZH2 promoter. In addition, ATPR can significantly increase the expression of lncRNA NR-104098, whereas knocking down NR104098 can inhibit the inhibitory effect of ATPR on the proliferation and induction differentiation of AML cells. Taken together, these results lead to deeper insight into the mechanism of ATPR-induced AML differentiation and prevent proliferation by inhibiting EZH2 on the transcriptional level.

ATPR-induced differentiation and G0/G1 phase arrest in acute promyelocytic leukemia by repressing EBP50/NCF1 complex to promote the production of ROS

Our previous study has demonstrated that 4-amino-2-trifluoromethyl-phenyl Retinate (ATPR) can induce human leukemia NB4 cells differentiation and G0/G1 phase arrest, but the underlying mechanism is still unclear. In this study, we used proteomics to screen differentially expressed protein profiles in NB4 cells before and after ATPR treatment in vitro. We analyzed the peptides digested from total cellular proteins by reverse phase LC-MS/MS and then performed label-free quantitative analysis. We found 27 significantly up-regulated proteins in the ATPR group compared to the control group. NCF1 was the most significantly changed protein. Immunoprecipitation and double immunofluorescent staining showed that EBP50 bind to NCF1. We further explored the potential molecular mechanism of EBP50/NCF1 complex in ATPR-induced differentiation and G0/G1 phase arrest. The results showed that ATPR remarkably reduced the expression of EBP50 in vivo and in vitro. Interestingly, the reduction of EBP50 contributed to ROS release by modulating the subcellular localization of NCF1. The reduction of EBP50 also contributed to G0/G1 phase arrest by inhibiting CyclinD1, CyclinA2 and CDK4, as well as promoting the differentiation of NB4 cells by increasing the expression of CD11b. Furthermore, we found that the overexpression of EBP50 restrained the effects of ATPR on differentiation and G0/G1 phase arrest in NB4 cells. These results suggest that ATPR-induced differentiation and G0/G1 phase arrest in acute promyelocytic leukemia (APL) by repressing EBP50/NCF1 complex to promote the production of ROS, and the results from in vivo experiments were consistent with those from in vitro studies. Therefore, our finding results suggest that EBP50 may be a new target for ATPR in the treatment of APL.

Efficiency of All-Trans Retinoic Acid on Gastric Cancer: A Narrative Literature Review

Gastric cancer (GC) is the third leading cause of cancer-related death worldwide with a five-year survival rate of around 25%, and 4% when diagnosed at a metastatic stage. Cancer stem cells (CSC) have recently been characterized as being responsible for resistance to radio/chemotherapies and metastasis formation, opening up perspectives for new targeted therapies. Those CSCs express biomarkers such as cluster of differentiation 44 (CD44) and display high aldehyde dehydrogenase activity that converts vitamin A-derived retinal into retinoic acids. All-trans retinoic acid (ATRA), which has pro-differentiating properties, has revolutionized the prognosis of acute promyelotic leukemia by increasing its remission rate from 15% to 85%. Recent studies have started to show that ATRA also has an anti-tumoral role on solid cancers such as GC. The purpose of this review is therefore to summarize the work that evaluated the effects of ATRA in GC and to evaluate whether its anti-cancerous action involves gastric CSCs targeting. It has been demonstrated that ATRA can block the cell cycle, enhance apoptosis, and decrease gastric CSCs properties in GC cell lines, tumorspheres, and patient-derived xenograft mice models. Therefore, retinoids and new synthetic retinoids seem to be a promising step forward in targeted therapy of gastric CSC in combination with existing chemotherapies. Future studies should probably focus on these points.

Role of eIF3a in 4-amino-2-trifluoromethyl-phenyl retinate-induced cell differentiation in human chronic myeloid leukemia K562 cells

4-amino-2-trifluoromethyl-phenyl retinate (ATPR), a novel all-trans retinoic acid (ATRA) derivative designed and synthesized by our team, has been demonstrated its anti-tumor effect through inducing differentiation and inhibiting proliferation. Eukaryotic initiation factor 3a (eIF3a) plays a critical role in affecting tumor cell proliferation and differentiation. However, whether eIF3a is implicated in chronic myeloid leukemia cells differentiation remains unclear. Our results demonstrated that eIF3a could be suppressed by ATPR in K562 cells. The results also confirmed that ATPR could arrest cell cycle in G0/G1 phase and induced differentiation. Moreover, over-expression of eIF3a promoted not only protein expression of c-myc and cyclin D1, but also prevented the expression of p-Raf-1, p-ERK and the myeloid differentiation markers CD11b and CD14 and had an influence on inducing the morphologic mature. However, silencing eIF3a expression by small interfering RNA could have an adverse effect on K562 cells. In addition, PD98059 (a MEK inhibitor) could block cell differentiation of CML cells and contributed to the expression of c-myc and cyclin D1. In conclusion, these results indicated that eIF3a played an important role in ATPR-induced cell differentiation in K562 cells, its mechanism might be related to its ability in regulating the activation of ERK1/2 signaling pathway in vitro.

ATPR-induced G0 /G1 phase arrest in gastric cancer cells by regulating the binding of 14-3-3ε and filamin A

4‐amino‐2‐trifluoromethyl‐phenyl retinate (ATPR) was able to induce the G₀/G₁ phase arrest in gastric cancer SGC‐7901 cells by downregulating 14‐3‐3ε. However, the mechanisms underlying this effect have not been fully elucidated. Because 14‐3‐3ε functions as a molecular chaperone on cell cycle regulation, the interaction between 14‐3‐3ε and the target proteins is worth an in‐depth study. In this study, the use of targeting proteomics identified 352 14‐3‐3ε‐binding proteins in SGC‐7901 cells. Analysis of gene ontology (GO) was performed using PANTHER to annotate the biological processes, protein classes, and pathways of these proteins. In 25 cell cycle‐related proteins, filamin A was reduced following ATPR treatment, and this change was validated by immunoprecipitation. The cell cycle was arrested at the G₀/G₁ phase following ATPR treatment or filamin A silencing in SGC‐7901 cells. Furthermore, subcellular expression analysis showed that 14‐3‐3ε and filamin A were transferred from the cytoplasm to the nucleus after ATPR treatment. On the other hand, overexpression of 14‐3‐3ε, in SGC‐7901 cells, resulted in an increase in the total cellular level of filamin A and an increase in the subcellular localization of filamin A in the cytoplasm. ATPR treatment of the 14‐3‐3ε overexpression cells decreased the total level of filamin A and redistributed filamin A protein from the cytoplasm to the nucleus. Immunohistochemical analysis showed that the expression levels of 14‐3‐3ε and filamin A in gastric cancer tissues were significantly higher, with a predominant localization in the cytoplasm, compared to the levels in matched tissues. Taken together, our results suggest that ATPR can induce nuclear localization of filamin A by reducing the binding of 14‐3‐3ε and filamin A, which may be the mechanism of ATPR‐induced G₀/G₁ phase arrest.

4-Amino-2-trifluoromethyl-phenyl retinate inhibits proliferation, invasion, and migration of breast cancer cells by independently regulating CRABP2 and FABP5

BACKGROUND

4-Amino-2-trifluoromethyl-phenyl retinate (ATPR), a novel retinoid derivative, inhibits proliferation and induces differentiation in many cancer cells. In this study, the inhibitory effects of ATPR on the proliferation, invasion, and migration of breast cancer (BC) cells, and the relationship between ATPR and the expression of the intracellular lipid-binding proteins CRABP2 and FABP5 were investigated.

METHODS

CRABP2 and FABP5 expression was evaluated in infiltrating breast-infiltrating ductal carcinoma(BIDC) and benign breast fibroma (BBF) by immunohistochemistry and in MCF-7, MDA-MB-231, MDA-MB-435, and MDA-MB-453 cells by immunofluorescence. The inhibition of proliferation by ATPR in these cells was detected by MTT. After downregulation and upregulation of CRABP2 and FABP5 in MCF-7 or MDA-MB-231 cells using siRNA and plasmids, the effect of ATPR on proliferation was detected by MTT and real-time cell analysis, and the effects of ATPR on the invasion and migration of MDA-MB-231 cells were detected using a Boyden chamber assay and a wound healing assay.

RESULTS

CRABP2 expression was moderately or strongly positive in BIDC and BBF. FABP5 expression was also moderately or strongly positive in BIDC, but weakly positive or negative in BBF. CRABP2 and FABP5 were highly expressed in MCF-7 cells, moderately expressed in MDA-MB-453 cells, and weakly expressed in MDA-MB-435 and MDA-MB-231 cells. ATPR inhibited proliferation more strongly in MCF-7 cells than in other cells. The inhibition of proliferation by ATPR depended on an increase in CRABP2, but not FABP5 expression. A decrease in FABP5 could inhibit the invasion and migration of BC cells.

CONCLUSION

These findings indicate that ATPR might inhibit proliferation by upregulating CRABP2, and inhibit invasion and migration by downregulating FABP5 in BC cells. These findings may facilitate the use of differentiation therapy in BC.

A novel all-trans retinoic acid derivative 4-amino‑2‑trifluoromethyl-phenyl retinate inhibits the proliferation of human hepatocellular carcinoma HepG2 cells by inducing G0/G1 cell cycle arrest and apoptosis via upregulation of p53 and ASPP1 and downregulation of iASPP

4-Amino-2-trifluoromethyl-phenyl retinate (ATPR), a novel all-trans retinoic acid (ATRA) derivative, was reported to function as a tumor inhibitor in various types of cancer cells in vitro. However, little is known concerning its antitumor effect on human hepatocellular carcinoma (HCC) HepG2 cells. The aims of the present study were to investigate the effects of ATPR on the proliferation of HepG2 cells and to explore the probable mechanisms. A series of experiments were performed following the treatment of HepG2 cells with ATRA and ATPR. MTT and plate colony formation assays were used to measure the cell viability. To confirm the influence on proliferation, flow cytometry was used to detect the distribution of the cell cycle. Apoptosis was observed by Hoechst staining and flow cytometry. In addition, to characterize the underlying molecular mechanisms, immunofluorescence was applied to observe the distribution of p53. The transcription and translation levels of p53 were analyzed by real-time quantitative RT-PCR (qRT-PCR) and western blotting. The expression levels of murine double minute 2 (MDM2), apoptosis stimulating proteins of p53 (ASPP), cell cycle- and apoptosis-associated proteins were detected by western blotting. After HepG2 cells were incubated with ATRA and ATPR, the viability of the HepG2 cells was inhibited in a dose- and time-dependent manner. As well, ATPR significantly suppressed HepG2 cell colony formation and arrested cells at the G0/G1 phase, while ATRA had no obvious effects. Both Hoechst staining and flow cytometry unveiled the apoptosis of HepG2 cells. Moreover, the fluorescent density of p53 was higher in the nuclei after exposure to ATPR than that in the ATRA group. HepG2 cells treated with ATPR showed elevated mRNA and protein levels of p53 when compared with these levels in the ATRA-treated cells. Western blotting showed that ATPR increased ASPP1, p21 and Bax expression and decreased MDM2, iASPP, cyclin D and E, cyclin-dependent kinase 6 (CDK6) and Bcl-2 expression, while CDK4 and ASPP2 expression were scarcely altered. Consequently, ATPR exerted a better inhibitory effect on the proliferation of HepG2 cells than ATRA through increased expression of p53 and ASPP1 and downregulation of iASPP, thereby resulting in G0/G1 cell cycle arrest and apoptosis.

A novel all-trans retinoid acid derivative induces apoptosis in MDA-MB-231 breast cancer cells

AIMS

To explore the effect and probable mechanism of a synthetic retinoid 4-amino-2-tri-fluoromethyl- phenyl ester (ATPR) on apoptosis of MDA-MB-231 breast cancer cells.

MATERIALS AND METHODS

MTT assays were performed to measure the proliferation of MDA-MB-231 cells treated with different concentrations of all- trans retinoic acid (ATRA) and ATPR. Morphologic changes were observed by microscopy. The apoptosis rates and cell cycling of MDA-MB-231 cells treated with ATRA or ATPR were assessed using flow cytometry analysis. Expression of retinoic acid receptor and phosphorylation of ERK, JNK, p38 proteins were detected by Western blotting.

RESULTS

Treatment of the cells with the addition of 15 μmol/L ATPR for 48 h clearly demonstrated reduced cell numbers and deformed cells, whereas no changes in the number and morphology were observed after treatment with ATRA. The apoptosis rate was 33.2% after breast cancer MDA-MB-231 cells were treated by ATPR (15 μmol/L) whereas ATRA (15 μmol/L) had no apoptotic effect. ATPR inhibited the phosphorylation of ERK, JNK, and p38 while ATRA had no significant effect. ATPR inhibited the expression of BiP and increased the expression of Chop at the protein level compared with control groups, ATRA and ATPR both decreased the protein expression of RXR α, ATPR reduced the protein expression of RARβ and RXRβ while ATRA did not decrease RARβ or RXRβ.

CONCLUSIONS

ATPR could induce apoptosis of breast cancer MDA-MB-231 cells, possible mechanisms being binding to RARβ/RXRβ heterodimers, then activation of ER stress involving the MAPK pathway.

Bevacizumab concomitant with chemotherapy is effective in treating Chinese patients with advanced non-squamous non-small cell lung cancer

OBJECTIVES

To retrospectively review the safety and clinical efficacy of bevacizumab concomitant with chemotherapy in Chinese patients with advanced non-squamous non-small cell lung cancer (NSNSCLC).

METHODS

Clinical data for 79 patients with NSNSCLC who received bevacizumab concomitant with chemotherapy in Chinese PLA General Hospital from April 28th 2009 to May 5th 2013 were retrospectively reviewed to analyze the clinical efficacy including disease control rate (DCR), overall response rate (ORR), progression-free survival (PFS), overall survival (OS), the Eastern Cooperative Oncology Group (ECOG) score and the safety.

RESULTS

The Eastern Cooperative Oncology Group (ECOG) score was 0-2. By the final cutoff date (June 9, 2013), 54 (68.4%) patients had disease progression and 37 (46.8%) died. The ORR was 32.9% and the DCR was 83.5%. The ORR of the first-, second-, and third- or later-line treatments were 51.4%, 25.0% and 12.5%, while the DCR were 94.3%, 80.0% and 70.8%, respectively. The median OS (mOS) and PFS (mPFS) were 13.5 and 5.83 months, respectively. The mOS of patients with the first-, second-, and third- or later-line treatments were 16.2, 10.9 and 8.30 months, while the mPFS were 7.27, 5.90 and 5.17 months, respectively. Chemotherapy-related adverse events included myelosuppression, vomiting, hepatic dysfunction and renal dysfunction, while the common serious bevacizumab-related adverse events were thromboembolic problems, gastrointestinal perforation and reversible posterior leukoencephalopathy syndrome, which could be well managed.

CONCLUSIONS

Bevacizumab concomitant with chemotherapy is effective and the related toxicity can be well tolerated in Chinese patients with NSNSCLC.

A novel all-trans retinoid acid derivative N-(3-trifluoromethyl- phenyl)- retinamide inhibits lung adenocarcinoma A549 cell migration through down-regulating expression of myosin light chain kinase

AIM

To observe the effects of a novel all-trans retinoid acid (ATRA) derivative, N-(3-trifluoromethyl-phenyl)- retinamide (ATPR), on lung adenocarcinoma A549 cells and to explore the potential mechanism of ATPR inhibiting of A549 cell migration.

MATERIALS AND METHODS

The cytotoxicity of ATRA and ATPR on A549 cells was assessed using MTT assay. Wound healing assays were used to analyze the influences of ATRA, ATPR, ML-7 (a highly selective inhibitor of myosin light chain kinase (MLCK)), PMA (an activator of MAPKs) and PD98059 (a selective inhibitor of ERK1/2) on the migration of A549 cells. Expression of MLCK and phosphorylation of myosin light chain (MLC) were assessed by Western blotting.

RESULTS

ATRA and ATPR inhibited the proliferation of A549 cells in a dose- and time-dependent manner, and the effect of ATPR was much more remarkable compared with ATRA. Relative migration rate and migration distance of A549 cells both decreased significantly after treatment with ATPR or ML-7. The effect on cell migration of PD98059 combining ATPR treatment was more notable than that of ATPR alone. Moreover, compared with control groups, the expression levels of MLCK and phosphorylated MLC in A549 cells were both clearly reduced in ATRA and ATPR groups.

CONCLUSIONS

ATPR could suppress the migration and invasion of A549 cells, and the mechanism might be concerned with down- regulating the expression of MLCK in the ERK-MAPK signaling pathway, pointing to therapeutic prospects in lung cancer.

Regulatory mechanisms of annexin-induced chemotherapy resistance in cisplatin resistant lung adenocarcinoma

Adenocarcinoma of lung has high incidence and a poor prognosis, woith chemotherapy as the main therapeutic tool, most commonly with cisplatin. However, chemotherapy resistance develops in the majority of patients during clinic treatment. Mechanisms of resistance are complex and still unclear. Although annexin play important roles in various tumor resistance mechanisms, their actions in cisplatin-resistant lung adenocarcinoma remain unclear. Preliminary studies by our group found that in cisplatin-resistant lung cancer A549 cells and lung adenocarcinoma tissues, both mRNA and protein expression of annexins A1, A2 and A3 is increased. Using a library of annexin A1, A2 and A3 targeting combined molecules already established by ourselves we found that specific targeting decreased cisplatin-resistance. Taken together, the underlined effects of annexins A1, A2 and A3 on drug resistance and suggest molecular mechanisms in cisplatin-resistant A549 cells both in vivo and in vitro. Furthermore, the study points to improved research on occurrence and development of lung adenocarcinoma, with provision of effective targets and programmes for lung adenocarcinoma therapy in the clinic.

Preparation and antitumor activity of a tamibarotene-furoxan derivative

Multi-target drug design, in which drugs are designed as single molecules to simultaneously modulate multiple physiological targets, is an important strategy in the field of drug discovery. QT-011, a tamibarotene-furoxan derivative, was here prepared and proposed to exert synergistic effects on antileukemia by releasing nitric oxide and tamibarotene. Compared with tamibarotene itself, QT-011 displayed stronger antiproliferative effects on U937 and HL-60 cells and was more effective evaluated in a nude mice U937 xenograft model in vivo. In addition, QT-011 could release nitric oxide which might contribute to the antiproliferative activity. Autodocking assays showed that QT-011 fits well with the hydrophobic pocket of retinoic acid receptors. Taken together, these results suggest that QT-011 might be a highly effective derivative of tamibarotene and a potential candidate compound as antileukemia agent.