A novel herbal formula induces cell cycle arrest and apoptosis in association with suppressing the PI3K/AKT pathway in human lung cancer A549 cells

Synergistic and Additive Effects of Herbal Medicines in Combination with Chemotherapeutics: A Scoping Review

BACKGROUND

Natural products are increasingly gaining interest as potential new drug candidates for cancer treatment. Herbal formula, which are combinations of several herbs, are primarily used in East Asia and have a long history of use that continues today. Recently, research exploring the combination of herbal formulas and chemotherapy for cancer treatment has been on the rise.

METHODS

This study reviewed research on the co-administration of herbal formulas and chemotherapy for cancer treatment. The databases PubMed, Embase, and Cochrane Library were used for article searches. The following keywords were employed: "Antineoplastic agents," "Chemotherapy," "Phytotherapy," "Herbal medicine," "Drug synergism," and "Synergistic effect." The selection process focused on studies that investigated the synergistic interaction between herbal formulas and chemotherapeutic agents.

RESULTS

Among the 30 studies included, 25 herbal formulas and 7 chemotherapies were used. The chemotherapy agents co-administered included cisplatin, 5-fluorouracil, docetaxel, doxorubicin, oxaliplatin, irinotecan, and gemcitabine. The types of cancer most frequently studied were lung, breast, and colon cancers. Most studies evaluating the anticancer efficacy of combined herbal formula and chemotherapy treatment were conducted in vitro or in vivo.

DISCUSSION

Most studies reported synergistic effects on cytotoxicity, apoptosis, and tumor growth inhibition. These effects were found to be associated with cell cycle arrest, anti-angiogenesis, and gene expression regulation. Further studies leading to clinical trials are required. Clinical experiences in East Asian countries could provide insights for future research.

Traditional Chinese medicine and lung cancer--From theory to practice

With the continuous breakthroughs in molecular biology and biochemistry, we have constantly made great progress in the treatment of lung cancer. There is no doubt that standard treatment (such as surgery, radiotherapy, chemotherapy, targeted therapy, and immunotherapy) has greatly improved the prognosis of lung cancer populations. In particular, the immunotherapy has brought more and more good news to countless lung cancer patients. In contrast to these standard treatments, traditional Chinese medicine (TCM) rarely has a profound and comprehensive overview in the field of lung cancer. This article will summarize the latest progress of TCM in lung cancer which is mainly non-small cell lung cancer (NSCLC) from theory to clinical practice, which would carry forward the sophisticated TCM and promote the development of modern medicine.

Study on metastasis inhibition of Kejinyan decoction on lung cancer by affecting tumor microenvironment

Background

Kejinyan decoction, as an experienced formula of Zhou Zhongying (the Master of Traditional Chinese Medicine) has been widely used in clinic for lung cancer treatment in China, while the anti-lung cancer mechanism of it is still remained to be elucidated. Herein, our basic study found that the survival of lung cancer xenograft mice was significantly prolonged after intragastrically administered high dose of Kejinyan decoction (3.8 g per kg BW) for 15 days. More importantly, we found that Kejinyan decoction inhibited the metastasis of lung cancer cells in vivo. Thus in this study, we aim to elucidate the anti-metastasis effects of Kejinyan decoction.

Methods

RNA-Seq was used to find out the gene regulation of Kejinyan decoction on the mice, flow cytometry assay was used to detect the immunocytes in the spleen, ELISA assay was used to detect the inflammatory factors in the serum and spleen, and immunofluorescence assay was used to detect the level of immune cells and the expression of glycol-metabolism related enzymes in situ. Also, we established a lung cancer orthotopic xenograft tumor model to assess the influence of Kejinyan decoction on the metastatic ability of lung cancer cells in vivo.

Results

GO analysis of gene sequencing of tumor tissue samples showed that Kejinyan decoction regulated immune response. Further flow cytometry analysis of splenic lymphocyte showed that Kejinyan decoction upregulated M1 macrophages and downregulated M2 macrophages, while the total level of macrophages changed little, which was verified by detection of CD68, F4/80, CD206, and CD86 in tumor tissue section. Moreover, detection of inflammatory cytokines showed that Kejinyan decoction downregulated TNF-α, IFN-γ, IL-6, as well as IL-4, IL-13 in tumor microenvironment. Further studies also showed that Kejinyan decoction had little effect on tumor hypoxia, but downregulated glycolysis in tumor tissues. More importantly, we found that Kejinyan decoction inhibited the metastasis of lung cancer cells in vivo.

Conclusion

Our findings conclude that Kejinyan decoction inhibited lung cancer cell metastasis through affecting macrophage polarization and energy reprogramming.

Discussion on Relevance and Studies of Prescription Compatibility in Chinese Medicine

With Chinese medicine (CM) gaining popularity in recent years, researchers and clinicians have put in much interest and effort into the makings and effects of it, especially after the recent announcement of World Health Orgnitation's incorporation of CM into mainstream medical compendium. Individual herb has complex properties, coming from its pharmacological properties and the Chinese medical principles of organ-directed, taste and dynamic orientational behaviours. The use of individual herb in CM is rare, where various herbs/ingredients are mostly found in a prescribed formula. To fully reveal the effects of CM is a great challenge. The complexity of various herbs in combined effect, the absorption and utility rate by the body, uniqueness of individual physique, sub-types of pathological behaviors and time-line progression of the healing process add on to the complication of understanding the full effect of CM. Various theories such as pathophysiology guidance, pharmacokinetic-pharmacodynamic compatibility method, and Global Systems Biology for Integrative Genomics, Proteomics and Metabolomics, which interactively provide a wider scope, more details, with the consideration of development timeline, may shed more light to revealing the full picture of the effects of compatibility prescription.

Modulation of Calretinin Expression in Human Mesothelioma Cells Reveals the Implication of the FAK and Wnt Signaling Pathways in Conferring Chemoresistance towards Cisplatin

Malignant mesothelioma (MM) is an aggressive asbestos-linked neoplasm, characterized by dysregulation of signaling pathways. Due to intrinsic or acquired chemoresistance, MM treatment options remain limited. Calretinin is a Ca²⁺-binding protein expressed during MM tumorigenesis that activates the FAK signaling pathway, promoting invasion and epithelial-to-mesenchymal transition. Constitutive calretinin downregulation decreases MM cells’ growth and survival, and impairs tumor formation in vivo. In order to evaluate early molecular events occurring during calretinin downregulation, we generated a tightly controlled IPTG-inducible expression system to modulate calretinin levels in vitro. Calretinin downregulation significantly reduced viability and proliferation of MM cells, attenuated FAK signaling and reduced the invasive phenotype of surviving cells. Importantly, surviving cells showed a higher resistance to cisplatin due to increased Wnt signaling. This resistance was abrogated by the Wnt signaling pathway inhibitor 3289-8625. In various MM cell lines and regardless of calretinin expression levels, blocking of FAK signaling activated the Wnt signaling pathway and vice versa. Thus, blocking both pathways had the strongest impact on MM cell proliferation and survival. Chemoresistance mechanisms in MM cells have resulted in a failure of single-agent therapies. Targeting of multiple components of key signaling pathways, including Wnt signaling, might be the future method-of-choice to treat MM.

Anti-Cancer and Ototoxicity Characteristics of the Curcuminoids, CLEFMA and EF24, in Combination with Cisplatin

In this study, we investigated whether the curcuminoids, CLEFMA and EF24, improved cisplatin efficacy and reduced cisplatin ototoxicity. We used the lung cancer cell line, A549, to determine the effects of the curcuminoids and cisplatin on cell viability and several apoptotic signaling mechanisms. Cellular viability was measured using the MTT assay. A scratch assay was used to measure cell migration and fluorescent spectrophotometry to measure reactive oxygen species (ROS) production. Western blots and luminescence assays were used to measure the expression and activity of apoptosis-inducing factor (AIF), caspases-3/7, -8, -9, and -12, c-Jun N-terminal kinases (JNK), mitogen-activated protein kinase (MAPK), and proto-oncogene tyrosine-protein kinase (Src). A zebrafish model was used to evaluate auditory effects. Cisplatin, the curcuminoids, and their combinations had similar effects on cell viability (IC₅₀ values: 2-16 μM) and AIF, caspase-12, JNK, MAPK, and Src expression, while caspase-3/7, -8, and -9 activity was unchanged or decreased. Cisplatin increased ROS yield (1.2-fold), and curcuminoid and combination treatments reduced ROS (0.75-0.85-fold). Combination treatments reduced A549 migration (0.51-0.53-fold). Both curcuminoids reduced auditory threshold shifts induced by cisplatin. In summary, cisplatin and the curcuminoids might cause cell death through AIF and caspase-12. The curcuminoids may potentiate cisplatin's effect against A549 migration, but may counteract cisplatin's effect to increase ROS production. The curcuminoids might also prevent cisplatin ototoxicity.

Sichong formula inhibits the proliferation and migration of human gastric cancer cells

Purpose

Traditional Chinese medicine (TCM) has gained increasing attention for the treatment of multiple chronic diseases, such as cancer. Here we aim to identify the antitumor activity of Sichong formula, a novel TCM, in human gastric cancer cells and investigate the underlying mechanisms.

Methods

The AGS and MKN45 gastric cancer cells were treated with Sichong formula at different concentrations. The proliferation rates were tested by CCK-8 and colony formation assays. Cell migration and invasion were tested by scratch and transwell assays. Gelatin zymography was used to detect the matrix metalloproteinase 9 (MMP9) activity in cell suspendents. Cell apoptosis was analyzed by Annexin V/PI staining and flow cytometry. The expression of interest proteins was tested by Western blot.

Results

Cell proliferation analysis indicated that Sichong formula inhibited cell viability of AGS and MKN45 cells in a dose- and time-dependent manner. The IC50 values were 240 μg/mL and 200 μg/mL for AGS and MKN45 cells, respectively. Furthermore, we found that Sichong formula could inhibit the invasion and migration of gastric cancer cells, which might be mediated by the downregulation of MMP9 activity. Flow cytometry results indicated that Sichong formula induced apoptosis in gastric cancer cells through upregulation of Bax/Bcl2 ratio and activation of caspase cascade. The results from Western blot indicated that Sichong formula resulted in cell autophagy and inactivation of AKT signaling pathway.

Conclusion

Our data suggest that Sichong formula inhibits the proliferation and migration and induces apoptosis in human gastric cancer cells. The inhibitory effect of Sichong formula was, at least partly, mediated by cell autophagy and AKT pathway.

Antitumor Effects of Ruyiping on Cell Growth and Metastasis in Breast Cancer

Background: Ruyiping is an effective traditional Chinese herbal medicine formula for preventing postoperative recurrence and metastasis of breast cancer. However, the exact function and underlying mechanism of Ruyiping in breast cancer remain unclear. Materials and Methods: After breast cancer cell lines MDA-MB-231 and MDA-MB-468 were treated with Ruyiping, the CCK8, colony formation, wound-healing, and transwell invasion assays were used to examine cell proliferation, migration, and invasion, respectively. Flow cytometry was performed to examine the effect of Ruyiping on cell cycle distribution. Western blot was performed to examine the expression of related proteins, and the activity of MMP9 was detected using Gelatin zymography assay. Results: Ruyiping treatment significantly inhibited cell proliferation and viability of MDA-MB-231 and MDA-MB-468 cells. Ruyiping was also revealed to trigger cell cycle arrest at the G2 phase in MDA-MB-231 and MDA-MB-468 cells. Moreover, Ruyiping suppressed the migration and invasion abilities of MDA-MB-231 and MDA-MB-468 cells in vitro. Furthermore, Ruyiping blocked the activity of MMP9 in MDA-MB-231 and MDA-MB-468 cells. Additionally, western blotting showed that Ruyiping attenuated epithelial-to-mesenchymal transition (EMT) of breast cancer through downregulation of N-cadherin, Vimentin, Snail1, and Snail2 and upregulation of E-cadherin. The authors observed that the components of Ruyiping Pseudobulbus Cremastra seu pleiones polysaccharide and curcumol showed significant suppression in the growth and invasion of breast cancer cell. Conclusions: The observations of this study suggest the antitumor properties of Ruyiping in cell growth and invasion of breast cancer, which are modulated by induction of cell cycle arrest and reduction of MMP9 and EMT.

Traditional Chinese Medicine Integrated with Chemotherapy for Stage II-IIIA Patients with Non-Small-Cell Lung Cancer after Radical Surgery: A Retrospective Clinical Analysis with Small Sample Size

Objective

This study was designed to evaluate the clinical efficacy of combined traditional Chinese medicine (TCM) and conventional chemotherapy versus conventional chemotherapy in patients with stage II-IIIA non-small-cell lung cancer (NSCLC) after radical surgery.

Methods

A retrospective cohort study was conducted in patients with stage II-IIIA NSCLC from Subei People's Hospital and Yangzhou Traditional Chinese Medicine Hospital in Yangzhou City of Jiangsu Province from 2012 to 2016. Patients were divided into two groups: the TCM user group (patients receiving treatment with integrated TCM and conventional chemotherapy) and the non-TCM user group (patients receiving conventional chemotherapy only). The two groups were compared for their median disease-free survival (DFS) and median overall survival (OS).

Results

A total of 67 patients with stage II-IIIA NSCLC were enrolled between January 2012 and December 2016. The median DFS for the non-TCM user group was 601 days (95% confidence interval [CI], 375.7-826.3). The median DFS for TCM user group could not be calculated. However, log-rank analysis showed that the median survival time in the TCM user group was significantly longer than that of the non-TCM user group (P < 0.05). In addition, several significant risk factors were detected for predicting disease prognosis in patients with NSCLC, such as age, ECOG, lymphatic metastasis, and body mass index (BMI). For patients harboring these independent risk factors, the DFS of TCM user group was much longer than that of non-TCM user group (P < 0.05).

Conclusion

Adjuvant therapy with TCM may reduce the rate of tumor recurrence and metastasis and prolong DFS of patients with stage II-IIIA NSCLC.

miRNA-125b regulates apoptosis of human non-small cell lung cancer via the PI3K/Akt/GSK3β signaling pathway

The present investigation demonstrated that regulation of microRNA (miR)-125b affected the apoptosis of human non-small cell lung cancer (NSCLC) through targeting of the PI3K/Akt and Wnt/β-catenin signaling pathways. The expression of miR-125b was assessed in patients with NSCLC, which demonstrated that miR-125b expression in NSCLC tissue was higher than that in para-carcinoma tissue. Furthermore, survival analysis of patients with NSCLC over 3 years indicated that the overall survival (OS) and disease-free survival (DFS) rates of patients with low miR-125b expression were higher than those of patients with high miR-125b expression. Proliferation and apoptosis assays were subsequently conducted in the human NSCLC cell line A549 using MTT assay and Annexin V-FITC/PI kits, respectively. Caspase-3 activity ELISA and western blot analysis were also used to assess caspase-3 activity and the protein expression of Bax, Akt, phosphorylated (p)-Akt, p-GSK3β, Wnt and β-catenin. It was observed that downregulation of miR-125b inhibited the proliferation and induced the apoptosis of A549 cells. Downregulation of miR-125b also suppressed the protein expression of p-Akt, Wnt and β-catenin, and increased caspase-3 activity and Bax protein expression in A549 cells. In addition, downregulation of miR-125b combined with the PI3K inhibitor LY294002 enhanced cell growth inhibition, suppression of p-GSK3β, Wnt and β-catenin protein expression and promotion of caspase-3 activity in A549 cells. These results revealed that the downregulation of miR-125b regulates apoptosis in human NSCLC through the suppression of the PI3K/Akt/GSK3β and Wnt/β-catenin signaling pathways.

Herbal formula YYJD inhibits tumor growth by inducing cell cycle arrest and senescence in lung cancer

Lung cancer represents a major cause of cancer-related death worldwide. Although various tactics and anti-tumor drugs have been used to improve curative effects, five-year survival rate of lung cancer patients remains poor. In this study, we investigated the action and underlying mechanisms of our recently optimized Chinese herbal formula Yangyinjiedu (YYJD) against lung cancer. YYJD significantly inhibits the proliferation of lung cancer cell lines (95-D, A549, H460 and H1975) by inducing cell cycle arrest and senescence in a dose-dependent manner. In particular, YYJD induces significant G2/M phase arrest and inhibits the colony formation of lung cancer cells. Moreover, we found that administration of YYJD could inhibit the growth of xenografted lung cancer cells in nude mice without loss in body weight. Our findings suggest that the herbal formula YYJD is a potential anti-tumor agent against lung cancer.

Gubenyiliu II Inhibits Breast Tumor Growth and Metastasis Associated with Decreased Heparanase Expression and Phosphorylation of ERK and AKT Pathways

Gubenyiliu II (GYII), a Traditional Chinese Medicine (TCM) formula used in our hospital, has shown beneficial effects in cancer patients. In this study, we investigated the molecular mechanisms underlying the beneficial effects of GYII on murine breast cancer models. GYII showed significant inhibitory effects on tumor growth and metastasis in the murine breast cancer model. Additionally, GYII suppressed the proliferation of 4T1 and MCF-7 cells in a dose-dependent manner. A better inhibitory effect on 4T1 cell proliferation and migration was found in the decomposed recipes (DR) of GYII. Moreover, heparanase expression and the degree of angiogenesis were reduced in tumor tissues. Western blot analysis showed decreased expression of heparanase and growth factors in the cells treated with GYII and its decomposed recipes (DR2 and DR3), and thereby a reduction in the phosphorylation of extracellular signal-regulated kinase (ERK) and serine-threonine kinase (AKT). These results suggest that GYII exerts anti-tumor growth and anti-metastatic effects in the murine breast cancer model. The anti-tumor activity of GYII and its decomposed recipes is, at least partly, associated with decreased heparanase and growth factor expression, which subsequently suppressed the activation of the ERK and AKT pathways.

[Advances in the Research of the Regulation of Chinese Traditional Medicine Monomer and Its Derivatives on Autophagy in Non-small Cell Lung Cancer]

The high morbidity and mortality of non-small cell lung cancer (NSCLC) did influence the quality of life of tumor patients world-wide. There is an urgent need to develop new therapies that have high anti-tumor activity and low toxicity side effects. It is widely accepted that autophagy can play diverse roles in carcinogenesis, such as induces pro-death of lung cancer cells or helps the escape from cell death, making it become a proper anticancer target. It's believed that various monomers of Chinese traditional medicine closely correlates to anti-NSCLC activities, and that even could affect the acquired multiple drug resistance (MDR). Furthermore, autophagy might be the underling mechanisms which could play a role as the candidate targets of natural active compounds. Recent studies of terpenoids, alkaloid, dietary polyphenols, saponins and other active ingredients that extracted from a large variety of herbs suggest that different monomer compounds could either regulate the activity of pro-death autophagy or influence the level of protective autophagy of NSCLC cells, thus changing their drug sensitivity and cell viability. This paper aims to give a systemic description of the latest advances about natural compounds and their derivatives that involved in tumorigenesis of NSCLC via inducing the autophagy.

Designing a broad-spectrum integrative approach for cancer prevention and treatment

Targeted therapies and the consequent adoption of "personalized" oncology have achieved notable successes in some cancers; however, significant problems remain with this approach. Many targeted therapies are highly toxic, costs are extremely high, and most patients experience relapse after a few disease-free months. Relapses arise from genetic heterogeneity in tumors, which harbor therapy-resistant immortalized cells that have adopted alternate and compensatory pathways (i.e., pathways that are not reliant upon the same mechanisms as those which have been targeted). To address these limitations, an international task force of 180 scientists was assembled to explore the concept of a low-toxicity "broad-spectrum" therapeutic approach that could simultaneously target many key pathways and mechanisms. Using cancer hallmark phenotypes and the tumor microenvironment to account for the various aspects of relevant cancer biology, interdisciplinary teams reviewed each hallmark area and nominated a wide range of high-priority targets (74 in total) that could be modified to improve patient outcomes. For these targets, corresponding low-toxicity therapeutic approaches were then suggested, many of which were phytochemicals. Proposed actions on each target and all of the approaches were further reviewed for known effects on other hallmark areas and the tumor microenvironment. Potential contrary or procarcinogenic effects were found for 3.9% of the relationships between targets and hallmarks, and mixed evidence of complementary and contrary relationships was found for 7.1%. Approximately 67% of the relationships revealed potentially complementary effects, and the remainder had no known relationship. Among the approaches, 1.1% had contrary, 2.8% had mixed and 62.1% had complementary relationships. These results suggest that a broad-spectrum approach should be feasible from a safety standpoint. This novel approach has potential to be relatively inexpensive, it should help us address stages and types of cancer that lack conventional treatment, and it may reduce relapse risks. A proposed agenda for future research is offered.

Potential Combinational Anti-Cancer Therapy in Non-Small Cell Lung Cancer with Traditional Chinese Medicine Sun-Bai-Pi Extract and Cisplatin

Traditional lung cancer treatments involve chemical or radiation therapies after surgical tumor removal; however, these procedures often kill normal cells as well. Recent studies indicate that chemotherapies, when combined with Traditional Chinese Medicines, may offer a new way to treat cancer. In vitro tests measuring the induction of autophagy and/or apoptosis were used to examine the cytotoxicity of SBPE, commonly used for lung inflammation on A549 cell line. The results indicated that intercellular levels of p62 and Atg12 were increased, LC3-I was cleaved into LC3-II, and autophagy was induced with SBPE only. After 24 hours, the apoptotic mechanism was induced. If the Cisplatin was added after cells reached the autophagy state, we observed synergistic effects of the two could achieve sufficient death of lung cancer cells. Therefore, the Cisplatin dosage used to induce apoptosis could be reduced by half, and the amount of time needed to achieve the inhibitory concentration of 50% was also half that of the original. In addition to inducing autophagy within a shortened period of time, the SBPE and chemotherapy drug combination therapy was able to achieve the objective of rapid low-dosage cancer cell elimination. Besides, SBPE was applied with Gemcitabine or Paclitaxel, and found that the combination treatment indeed achieve improved lung cancer cell killing effects. However, SBPE may also be less toxic to normal cells.

Ophiopogonin B induces apoptosis, mitotic catastrophe and autophagy in A549 cells

Ophiopogonin B (OP-B), a saponin compound isolated from Radix Ophiopogon japonicus, was verified to inhibit cell proliferation in numerous non-small cell lung cancer (NSCLC) cells in our previous study. However, the precise mechanisms of action have remained unclear. In the present study, we mainly investigated the effects of OP-B on adenocarcinoma A549 cells to further elaborate the underlying mechanisms of OP-B in different NSCLC cell lines. Detection by high content screening (HCS) and TUNEL assay verified that OP-B induced apoptosis in this cell line, while detection of Caspase-3, Bcl-2 and Bax showed that OP-B induced cell death was caspase and mitochondrial independent. Further experiments showed that OP-B induced cell cycle arrest in the S and G2/M phases by inhibiting the expression of Myt1 and phosphorylation of Histone H3 (Ser10), which resulted in mitotic catastrophe in the cells. Transmission electron microscopy (TEM) observation of cell micro-morphology combined with detection of Atgs by western blot analysis showed that OP-B induced autophagy in this cell line. Autophagy inhibition by the lysosome inhibitor CQ or Beclin1-siRNA knockdown both attenuated cell viability, demonstrated that autophagy also being the vital reason resulted in cell death. More importantly, the xenograft model using A549 cells provided further evidence of the inhibition of OP-B on tumor proliferation. Immunohistochemistry detection of LC3 and Tunel assay both verified that high dose of OP-B (75 mg/kg) induced autophagy and apoptosis in vivo, and western blot detection of p-Histone H3 (Ser10), Survivin and XIAP further indicated the molecular mechanism of OP-B in vivo. As our findings revealed, multiple types of cell death overlapped in OP-B treated A549 cells, it displayed multitarget characteristics of the compounds extracted from the Chinese herbal, which may be used as candidate anticancer medicine in clinic.

Japonicone A inhibits the growth of non-small cell lung cancer cells via mitochondria-mediated pathways

Japonicone A, which is a natural product isolated from the aerial part of Inula japonica Thunb., has a wide range of clinical applications, including anti-inflammation and anti-oxidation. This study investigated the effects of japonicone A on the growth of non-small cell lung cancer (NSCLC) cell lines. The results showed that japonicone A significantly inhibited the growth of NSCLC cell lines in a dose- and time-dependent manner. This product also blocked cell cycle progression at S phase and induced mitochondrial-related apoptosis by upregulating Bax, cleaved caspase-9, cleaved caspase-3, and cleaved poly(ADP-ribose) polymerase (PARP) protein levels and by downregulating Bcl-2, cyclin D1, CDC25A, and CDK2 protein levels. In vivo, japonicone A suppressed tumor growth via the same mechanism as that observed in vitro. In conclusion, our study is the first to report that japonicone A has an inhibitory effect on the growth of NSCLC cells, indicating that japonicone A administration is a potential therapeutic approach for future NSCLC treatments.

MicroRNA-33a inhibits lung cancer cell proliferation and invasion by regulating the expression of β-catenin

MicroRNAs (miRNAs) are short, non‑coding RNAs that are aberrantly expressed in tumors. miRNA‑33a (miR‑33a) is closely associated with cholesterol metabolism and is essential for cellular growth. The aim of the present study was to explore the role of miR‑33a and identify its clinical significance in lung cancer cells. miR‑33a was observed to be overexpressed in the lung cancer cell lines A549 and NCI‑H460. MTT assay results demonstrated that the overexpression of miR‑33a significantly inhibited the proliferation of A549 cells, and similar results were obtained from the colony formation assay. This suggests that transfection of miR‑33a may suppress the growth of lung cancer cells. Overexpression of miR‑33a was also observed to result in marked G1/S phase cell cycle arrest in A549 and NCI‑H460 cell lines using fluorescence‑activated cell sorting analysis. Western blot analysis revealed that overexpression of miR‑33a significantly reduced the expression of β‑catenin in A549 and NCI‑H460 cells, suggesting a direct or indirect regulation of β‑catenin by miR‑33a in lung cancer cells. In conclusion, the current study may provide strategies for the treatment of lung cancer and clarify the mechanism of its progression.