Molecular targeted therapy for early-stage non-small-cell lung cancer: Will it increase the cure rate?

MicroRNA-185-5p targets tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta to regulate non-small cell lung cancer progression

BACKGROUND

Lung cancer (LC) is one of the most frequent cancers worldwide, as well as the leading cause of cancer-related death. Non-small cell lung cancer (NSCLC, which accounts for 85% of occurrences) is the main type of LC. MiRNAs appear to play a role in the occurrence and progression of many malignancies, according to mounting data. The underlying mechanism of miRNAs in regulating NSCLC cell biological activity and progression, on the other hand, is still being investigated.

METHODS

QRT-PCR were used to detect miR-185-5p expression and YWHAZ mRNA in NSCLC. The CCK-8 assay was used to determine the tumor cells' ability to proliferate. Transwall assay was used to test the migratory and invasive properties of cells. Cell apoptosis was detected using flow cytometry. Tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein zeta (YWHAZ), E-Cadherin, N-Cadherin and cleaved-caspase3 protein expression were assessed using Western Blot. The bioinformatics analysis software StarBase2.0 predicted miR-185-5p downstream targets. To confirm the target association between miR-185-5p and YWHAZ, a luciferase experiment was used. In addition, an NCl-H1299 xenograft model was created to assess the anti-tumor impact of miR-185-5p in vivo. The expression level of YWHAZ in tumor tissues of small xenograft tumor model was detected by immunohistochemistry assay.

RESULTS

Decreased miR-185-5p expression levels were observed in NSCLC. In vitro, over-expressed miR-185-5p decreased cell viability, proliferation, invasion/migration, and induced cell apoptosis, while inhibiting tumor growth in vivo. Dual-luciferase gene experiments confirmed that YWHAZ binds to miR-185-5p. Overexpression of YWHAZ partially restored the inhibitory effects of miR-185-5p on cell behaviors.

CONCLUSION

MiR-185-5p was down-regulated in NSCLC, and that overexpressed miR-185-5p inhibited malignant behaviors of cells and tumor growth by negatively regulating YWHAZ.

TP63 Functions as a Tumor Suppressor Regulated by GAS5/miR-221-3p Signaling Axis in Human Non-Small Cell Lung Cancer Cells

Background

Tumor protein p63 (TP63) has been proven to play a role as a tumor suppressor in some human cancers, including non-small cell lung cancer (NSCLC). This study aimed to investigate the mechanism of TP63 and analyze the underlying pathway dysregulating TP63 in NSCLC.

Methods

RT-qPCR and Western blotting assays were used to determine gene expression in NSCLC cells. The luciferase reporter assay was performed to explore the transcriptional regulation. Flow cytometry was used to analyze the cell cycle and cell apoptosis. Transwell and CCK-8 assays were performed to test cell invasion and cell proliferation, respectively.

Results

GAS5 interacted with miR-221-3p, and its expression was significantly reduced in NSCLC. GAS5, as a molecular sponge, upregulated the mRNA and protein levels of TP63 by inhibiting miR-221-3p in NSCLC cells. The upregulation of GAS5 inhibited cell proliferation, apoptosis, and invasion, which was partially reversed by the knockdown of TP63. Interestingly, we found that GAS5-induced TP63 upregulation promoted tumor chemotherapeutic sensitivity to cisplatin therapy in vivo and in vitro.

Conclusion

Our results revealed the mechanism by which GAS5 interacts with miR-221-3p to regulate TP63, and targeting GAS5/miR-221-3p/TP63 may be a potential therapeutic strategy for NSCLC cells.

FGFC1 Exhibits Anti-Cancer Activity via Inhibiting NF-κB Signaling Pathway in EGFR-Mutant NSCLC Cells

FGFC1, an active compound isolated from the culture of marine fungi Stachybotrys longispora FG216, elicits fibrinolytic, anti-oxidative, and anti-inflammatory activity. We have previously reported that FGFC1 inhibited the proliferation, migration, and invasion of the non-small cell lung cancer (NSCLC) cells in vitro. However, the precise mechanisms of FGFC1 on NSCLC and its anti-cancer activity in vivo remains unclear. Hence, this study was focused to investigate the effects and regulatory mechanisms of FGFC1 on two NSCLC cell lines, EGFR-mutant PC9 (ex19del) and EGFR wild-type H1299. Results suggested that FGFC1 significantly inhibited proliferation, colony formation, as well as triggered G0/G1 arrest and apoptosis of PC9 cells in a dose- and time-dependent manner, but no obvious inhibitory effects were observed in H1299 cells. Subsequently, transcriptome analysis revealed that FGFC1 significantly down-regulated 28 genes related to the NF-κB pathway, including IL-6, TNF-α, and ICAM-1 in the PC9 cells. We further confirmed that FGFC1 decreased the expression of protein p-IKKα/β, p-p65, p-IκB, IL-6, and TNF-α. Moreover, NF-κB inhibitor PDTC could strengthen the effects of FGFC1 on the expression of CDK4, Cyclin D1, cleaved-PARP-1, and cleaved-caspase-3 proteins, suggesting that the NF-κB pathway plays a major role in FGFC1-induced cell cycle arrest and apoptosis. Correspondingly, the nuclear translocation of p-p65 was also suppressed by FGFC1 in PC9 cells. Finally, the intraperitoneal injection of FGFC1 remarkably inhibited PC9 xenograft growth and decreased the expression of Ki-67, p-p65, IL-6, and TNF-α in tumors. Our results indicated that FGFC1 exerted anti-cancer activity in PC9 cells via inhibiting the NF-κB signaling pathway, providing a possibility for FGFC1 to be used as a lead compound for the treatment of NSCLC in the future.

Bufalin inhibits the malignant development of non-small cell lung cancer by mediating the circ_0046264/miR-522-3p axis

BACKGROUND

Bufalin is an active component of the traditional Chinese medicine "Chan Su" and is reported to play anti-tumor roles in cancer development, but its functional mechanism is largely unclear. This study intends to explore a potential action mode of bufalin in NSCLC.

MATERIALS AND METHODS

The malignant properties of NSCLC, including cell viability, proliferation, adhesion capacity, migration and invasion, were monitored by cell counting kit-8 (CCK-8), adhesion assay and transwell assay, respectively. The expression of circ_0046264 and miR-522-3p was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The expression of proliferation- and migration-related markers was examined by western blot. The putative relationship between circ_0046264 and miR-522-3p was verified by dual-luciferase reporter assay, RIP assay and RNA pull-down assay. Animal experiments in nude mice were performed to investigate the role of bufalin in vivo.

RESULTS

Bufalin treatment inhibited cell viability, colony formation, cell adhesion capacity, migration and invasion in NSCLC cells. Bufalin facilitated the expression of circ_0046264, and circ_0046264 overexpression also inhibited NSCLC cell viability, colony formation, cell adhesion capacity, migration and invasion. Besides, circ_0046264 knockdown partially counteracted the effects of bufalin. Further, miR-522-3p was identified as a target of circ_0046264, and its deficiency reversed the effects of circ_0046264 knockdown to suppress malignant activities of NSCLC cells. In addition, bufalin restrained the tumor growth and development in vivo via enhancing the expression of circ_0046264.

CONCLUSION

Bufalin played an anti-tumor role in NSCLC by modulating the circ_0046264/miR-522-3p pathway, which might be a potential functional mechanism of bufalin in NSCLC.

Effect and mechanism of miR-146a on malignant biological behaviors of lung adenocarcinoma cell line

The aim of the present study was to assess the expression of microRNA-146a (miR-146a) in human lung adenocarcinoma cells, its effect on cellular behaviors, and the underlying molecular mechanisms. Reverse transcription-quantitative PCR (RT-qPCR) was used to measure miR-146a expression in the human normal lung epithelial cell line, BEAS-2B, and human lung adenocarcinoma cell lines, A549, PC-9 and H1299, to determine whether miR-146a acts as an oncogene or anti-oncogene. miR-146a mimics were transfected into target cells to observe the proliferation, apoptosis, invasion and migration of human lung adenocarcinoma cells. The target genes of miR-146a were predicted using bioinformatics analysis, and binding sites were validated by dual-luciferase reporter assay. Target gene expression at the mRNA and protein levels was measured by RT-qPCR and western blot analysis, respectively. The expression levels of miR-146a in human lung adenocarcinoma cell lines were lower than its expression in BEAS-2B (P<0.01). A549 cell line is a EGFR wild-type lung adenocarcinoma cell line, which is also the most widely studied in NSCLC, and therefore this was chosen as the target cell line for further investigation. Overexpression of miR-146a in A549 cells can inhibit cell proliferation (P<0.05), promote apoptosis (P<0.05), and reduce the cells' migratory ability (P<0.01). Bioinformatics prediction indicated that interleukin-1 receptor-associated kinase 1 (IRAK1) and TNF receptor associated factor 6 (TRAF6) are the target genes of miR-146a. Dual-luciferase reporter assay showed that miR-146a could specifically bind to 3′-untranslated regions of IRAK1 and TRAF6. The protein and mRNA levels of IRAK1 and TRAF6 were significantly downregulated after miR-146a overexpression in A549 cells (P<0.01). The results of this study demonstrated that the expression of miR-146a in human lung adenocarcinoma cells was significantly lower than in normal lung epithelial cells, indicating that miR-146a acts as an anti-oncogene. miR-146a suppresses the proliferation and migration of human lung adenocarcinoma cells by downregulating the expression of IRAK1 and TRAF6.

Identification and Analysis of Dysfunctional Genes and Pathways in CD8+ T Cells of Non-Small Cell Lung Cancer Based on RNA Sequencing

Lung cancer, the most common of malignant tumors, is typically of the non-small cell (NSCLC) type. T-cell-based immunotherapies are a promising and powerful approach to treating NSCLCs. To characterize the CD8⁺ T cells of non-small cell lung cancer, we re-analyzed the published RNA-Seq gene expression profiles of 36 CD8⁺ T cell isolated from tumor (TIL) samples and 32 adjacent uninvolved lung (NTIL) samples. With an advanced Monte Carlo method of feature selection, we identified the CD8⁺ TIL specific expression patterns. These patterns revealed the key dysfunctional genes and pathways in CD8⁺ TIL and shed light on the molecular mechanisms of immunity and use of immunotherapy.

MiR-206 may suppress non-small lung cancer metastasis by targeting CORO1C

Object

Non-small lung cancer (NSCLC), with a poor 5-year survival rate (16%), is the major type of lung cancer. Metastasis has been identified as the main factor that leads to NSCLC therapy failure. MiR-206 is a metastasis suppressor in many cancers, including colorectal cancer, renal cell carcinoma and breast cancer. However, the role of miR-206 in NSCLC metastasis and the underlying mechanism are still obscure.

Methods

Quantitative reverse-transcription PCR (q-RT-PCR) assay was used to detect miR-206 mRNA of NSCLC tissues and lung cancer lines. The MTT assay, scratch wound healing assay, transwell migration assay and transwell invasion assay were conducted to illuminate the effect of miR-206 on A549 cells’ proliferation, migration and invasion. Gaussia luciferase reporter assay, q-RT-PCR and western blotting assay were used to explore the underlying mechanism. Also, the A549 xenograft model was conducted to evaluate the anti-tumor effect of miR-206 in vivo.

Results

The results showed that miR-206 expression was decreased in NSCLC tissues and lung cancer cells. Further research demonstrated that miR-206 inhibited the proliferation, migration and invasion of A549 cells via negatively regulating Coronin-1C (CORO1C), and CORO1C deletion significantly rescues the miR-206 mediated inhibitory effect on A549 cells. Moreover, miR-206 exhibited a perfect anti-tumor effect in the A549 xenograft model.

Conclusion

Our study reveals that miR-206 functions as a tumor metastasis suppressor and sheds new light on the clinical significance of miR-206 in NSCLC therapy.

Fluzoparib increases radiation sensitivity of non-small cell lung cancer (NSCLC) cells without BRCA1/2 mutation, a novel PARP1 inhibitor undergoing clinical trials

PROPOSE

Poly (ADP-ribose) polymerase 1 inhibitors were originally investigated as anti-cancer therapeutics with BRCA1/2 genes mutation. Here, we investigate the effectiveness of a novel PARP1 inhibitor fluzoparib, for enhancing the radiation sensitivity of NSCLC cells lacking BRCA1/2 mutation.

METHODS

We used MTS assays, western blotting, colony formation assays, immunofluorescence staining, and flow cytometry to evaluate the radiosensitization of NSCLC cells to fluzoparib and explore the underlying mechanisms in vitro. Through BRCA1 and RAD50 genes knockdown, we established dysfunctional homologous recombination (HR) DNA repair pathway models in NSCLC cells. We next investigated the radiosensitization effect of fluzoparib in vivo using human NSCLC xenograft models in mice. The expression of PARP1 and BRCA1 in human NSCLC tumor samples was measured by immunohistochemistry. Furthermore, we sequenced HR-related gene mutations and analyzed their frequencies in advanced NSCLC.

RESULTS

In vitro experiments in NSCLC cell lines along with in vivo experiments using an NSCLC xenograft mouse model demonstrated the radiosensitization effect of fluzoparib. The underlying mechanisms involved increased apoptosis, cell-cycle arrest, enhanced irradiation-induced DNA damage, and delayed DNA-damage repair. Immunohistochemical staining showed no correlation between the expression of PARP1 and BRCA1. Moreover, our sequencing results revealed high mutation frequencies for the BRCA1/2, CHEK2, ATR, and RAD50 genes.

CONCLUSION

The potential therapeutic value of fluzoparib for increasing the radiation sensitivity of NSCLC is well confirmed. Moreover, our findings of high mutation frequencies among HR genes suggest that PARP1 inhibition may be an effective treatment strategy for advanced non-small cell lung cancer patients.

Effects of MALAT1 on proliferation and apo- ptosis of human non-small cell lung cancer A549 cells in vitro and tumor xenograft growth in vivo by modulating autophagy

OBJECTIVE

To explore the ability of MALAT1 to influence non-small cell lung cancer (NSCLC) A549 cells in vitro and tumor xenograft growth in vivo by modulating autophagy.

METHODS

LncRNA MALAT-1 in normal HBE cells and human NSCLC cells was measured. A549 cells were treated with si-MALAT-1, negative control and si-MALAT-1 + rapamycin. The mRNA levels of MALAT-1, P62 and LC3 was determined by the qRT-PCR and the protein levels of autophagy-related proteins by the western blotting. The CCK8 assay was performed for cell proliferation, the scratch test for cell migration, the Transwell assay for cell invasion, and the flow cytometry for cell cycle and apoptosis. Tumor xenograft in nude mice is performed to test tumorigenesis of the transfected A549 cells.

RESULTS

The expression level of MALAT-1 in A549, SPC-A-1 and NCI-H460 cells was increased compared to HBE cells. And A549 with a high expression level of MALAT-1 were selected for cell transfection. si-MALAT-1 decreased cell proliferation, migration, invasion, and LC3-II/LC3-I ratio, reduced cell cycle progression, and increased cell apoptosis and P62 protein expression. No significant difference was found between A549 cells and A549 cells transfected with si-MALAT-1 + RAPA, A549 cells transfected with NC and A549 cells transfected with si-MALAT-1 + RAPA. Nude mice injected with A549 cells transfected with si-MALAT-1 had smallest tumor on size and weight among other nude mice.

CONCLUSION

Downregulation of MALAT1 may promote apoptosis and suppress proliferation, migration and invasion of human NSCLC A549 cells by inhibiting autophagy, thereby suppressing the development of NSCLC.

Role of Immunotherapy for Oncogene-Driven Non-Small Cell Lung Cancer

The clinical application of immune checkpoint inhibitors (ICIs) has led to dramatic changes in the treatment strategy for patients with advanced non-small cell lung cancer (NSCLC). Despite the observation of improved overall survival in NSCLC patients treated with ICIs, their efficacy varies greatly among different immune and molecular profiles in tumors. Particularly, the clinical significance of ICIs for oncogene-driven NSCLC has been controversial. In this review, we provide recent clinical and preclinical data focused on the relationship between oncogenic drivers and immunological characteristics and discuss the future direction of immunotherapy in NSCLC patients harboring such genetic alterations.

Post surgery circulating free tumor DNA is a predictive biomarker for relapse of lung cancer

Cancer cells release DNA fragments into plasma as circulating free DNA (cfDNA). However, quantitative measurement of tumor-derived DNA in cfDNA remains challenge. The purpose of this study was to quantitatively assess tumor-derived DNA in lung cancer patients. By optimizing competitive allele-specific TaqMan PCR (CAST-PCR), we assessed the copy number of mutated Kirsten rat sarcoma viral oncogene homolog (KRAS) and epidermal growth factor receptor (EGFR) alleles in the pre/post surgery plasma of 168 lung cancer patients. An absolute quantitative PCR method was developed to assess the number of total cfDNA. All mutations detected in tumors were also found in the plasma after surgery. At the time of 30 days after surgery, EGFR mutation of circulating cell-free DNA was detected only in two patients who recurred in 4 months after surgery. Compared to that of normal control at 30 days after surgery, five patients who recurred in 4 months had significantly higher circulating cell-free DNA (P < 0.001), whereas six patients who recurred after 4 months (P = 0.207) and five patients without recurrence (P = 0.901) demonstrated significantly lower circulating cell-free DNA. Our findings suggest that cfDNA analysis in plasma is an alternative and supplement to tissue analysis and hold promise for clinical application. Stratification of patients according to cfDNA levels at 30 days after surgery might be helpful in selecting lung cancer patients for adjuvant therapy after surgery.

Gefitinib induces lung cancer cell autophagy and apoptosis via blockade of the PI3K/AKT/mTOR pathway

Gefitinib is a selective inhibitor of the tyrosine kinase epidermal growth factor receptor, which inhibits tumor pathogenesis, metastasis and angiogenesis, as well as promoting apoptosis. Therefore, gefitinib presents an effective drug for the targeted therapy of lung cancer. However, the underlying mechanisms by which gefitinib induces lung cancer cell death remain unclear. To investigate the effects of gefitinib on lung cancer cells and the mechanism of such, the present study analyzed the effect of gefitinib on the autophagy, apoptosis and proliferation of the A549 and A549-gefitinib-resistant (GR) cell lines GR. The regulation of the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/ mammalian target of rapamycin (mTOR) pathway was also investigated. Acridine orange staining revealed that gefitinib induced autophagy of A549 cells but not A549-GR cells. In addition, gefitinib promoted apoptosis and inhibited proliferation of A549 cells but not A549-GR cells. Furthermore, western blot analysis demonstrated that gefitinib treatment led to the downregulation of PI3K, AKT, pAKT, mTOR and phosphorylated-mTOR protein expression in A549 cells but not A549-GR cells. LY294002 blocked the PI3K/AKT/mTOR pathway and induced autophagy and apoptosis of A549 cells, however, no synergistic effect was observed following combined treatment with gefitinib and LY294002. In conclusion, the results of the present study indicate that gefitinib promotes autophagy and apoptosis of lung cancer cells via blockade of the PI3K/AKT/mTOR pathway, which leads to lung cancer cell death.

Upregulation of PD-L1 by EGFR Activation Mediates the Immune Escape in EGFR-Driven NSCLC: Implication for Optional Immune Targeted Therapy for NSCLC Patients with EGFR Mutation

INTRODUCTION

Epidermal growth factor receptor (EGFR) mutation status was reported to be associated with programmed death-ligand 1 (PD-L1) expression. However, the molecular mechanism of PD-L1 regulation by EGFR activation and the potential clinical significance of blocking PD-1/PD-L1 in EGFR-mutant non-small-cell lung cancer (NSCLC) treated with EGFR tyrosine kinase inhibitors (TKIs) were largely unknown.

METHODS

Western blot, real-time polymerase chain reaction, immunofluorescence, and flow cytometry were employed to explore the association between PD-L1 and EGFR activation. Then, we used EGFR-TKIs and downstream pathways inhibitors to clarify the detailed signaling pathway involved in PD-L1 regulation. Cell apoptosis, viability, and enzyme-linked immunosorbent assay test were used to study the immune suppression by EGFR activation and immune reactivation by EGFR-TKIs and/or PD-1 blocking in tumor cells and human peripheral blood mononuclear cells coculture system.

RESULTS

We found that EGFR activation by EGF stimulation, exon-19 deletions, and L858R mutation could induce PD-L1 expression. EGFR activation upregulated PD-L1 through p-ERK1/2/p-c-Jun but not through p-AKT/p-S6 pathway. PD-L1 mediated by EGFR activation could induce the apoptosis of T cells through PD-L1/PD-1 axis in tumor cells and peripheral blood mononuclear cells coculture system. Inhibiting EGFR by EGFR-TKIs could free the inhibition of T cells and enhance the production of interferon-γ. Synergistic tumor cell killing effects were not observed with EGFR-TKIs and anti-PD-1 antibody combination treatment in coculture system.

CONCLUSIONS

Our results imply that EGFR-TKIs could not only directly inhibit tumor cell viability but also indirectly enhance antitumor immunity through the downregulation of PD-L1. Anti-PD-1/PD-L1 antibodies could be an optional therapy for EGFR-TKI sensitive patients, especially for EGFR-TKIs resistant NSCLC patients with EGFR mutation. Combination of EGFR-TKIs and anti-PD-1/PD-L1 antibodies treatment in NSCLC is not supported by the current study but warrant more studies to move into clinical practice.

Tyrosine Kinase Inhibitors for the Elderly

Until few years ago non-specific cytotoxic agents were considered the tip of the arrow as first line treatment for lung cancer. However; age > 75 was considered a major drawback for this kind of therapy. Few exceptions were made by doctors based on the performance status of the patient. The side effects of these agents are still severe for several patients. In the recent years further investigation of the cancer genome has led to targeted therapies. There have been numerous publications regarding novel agents such as; erlotinib, gefitinib and afatinib. In specific populations these agents have demonstrated higher efficiency and this observation is explained by the overexpression of the EGFR pathway in these populations. We suggest that TKIs should administered in the elderly, and with the word elderly we propose the age of 75. The treating medical doctor has to evaluate the performance status of a patient and decide the best treatment in several cases indifferent of the age. TKIs in most studies presented safety and efficiency and of course dose modification should be made when necessary. Comorbidities should be considered in any case especially in this group of patients and the treating physician should act accordingly.

Upregulation of PD-L1 by EML4-ALK fusion protein mediates the immune escape in ALK positive NSCLC: Implication for optional anti-PD-1/PD-L1 immune therapy for ALK-TKIs sensitive and resistant NSCLC patients

Driver mutations were reported to upregulate programmed death-ligand 1 (PD-L1) expression. However, how PD-L1 expression and immune function was affected by ALK-TKIs and anti-PD-1/PD-L1 treatment in ALK positive non-small-cell lung cancer (NSCLC) remains poorly understood. In the present study, western-blot, real-time PCR, flow cytometry and immunofluorescence were employed to explore how PD-L1 was regulated by ALK fusion protein. ALK-TKIs and relevant inhibitors were used to identify the downstream signaling pathways involved in PD-L1 regulation. Cell apoptosis, viability and Elisa test were used to study the immune suppression by ALK activation and immune reactivation by ALK-TKIs and/or PD-1 blocking in tumor cells and DC-CIK cells co-culture system. We found that PD-L1 expression was associated with EGFR mutations and ALK fusion genes in NSCLC cell lines. Over-expression of ALK fusion protein increased PD-L1 expression. PD-L1 mediated by ALK fusion protein increased the apoptosis of T cells in tumor cells and DC-CIK cells co-culture system. Inhibiting ALK by sensitive TKIs could enhance the production of IFNγ. Anti-PD-1 antibody was effective in both crizotinib sensitive and resistant NSCLC cells. Synergistic tumor killing effects were not observed with ALK-TKIs and anti-PD-1 antibody combination in co-culture system. ALK-TKIs not only directly inhibited tumor viability but also indirectly enhanced the antitumor immunity via the downregulation of PD-L1. Anti-PD-1/PD-L1 antibodies could be an optional therapy for crizotinib sensitive, especially crizotinib resistant NSCLC patients with ALK fusion gene. Combination of ALK-TKIs and anti-PD-1/PD-L1 antibodies treatment for ALK positive NSCLC warrants more data before moving into clinical practice.