Epidermal growth factor receptor tyrosine kinase inhibitors for the treatment of non-small cell lung cancer

Clinical features and prognostic nomogram development for cancer-specific death in patients with dual primary lung cancer: a population-based study from SEER database

OBJECTIVE

This study aimed to develop a concise and valid clinical prediction model to assess the survival prognostic risk of cancer-specific death in patients with dual primary lung cancer (DPLC).

DATA SOURCE

Surveillance, epidemiology, and end results (SEER) database.

DESIGN

A retrospective population-based study.

METHODS

Data of DPLC patients from the database from 1992 to 2020 were collected. The number of DPLC patients was determined based on the first primary LC (FPLC) and second primary LC (SPLC), and patients were randomly assigned to a training set and a testing set in a 7:3 ratio. The primary endpoint was cancer-specific survival (CSS). Kaplan-Meier survival analysis was performed to construct survival curves. Cox analysis and bilateral stepwise regression were used to analyze prognostic factors for cancer-specific death in patients and establish the nomogram. The discriminative ability of the nomogram was assayed by C-index and calibration curves, decision-making ability was assessed by decision curve analysis (DCA), and nomogram performance was measured by receiver operating characteristic (ROC) curves.

RESULTS

This study included 997 DPLC patients, divided into a training set (n = 698) and a testing set (n = 299) in a 7:3 ratio. Age, gender, histological type, surgery, chemotherapy, T stage, N stage, and tumor size were identified as risk factors affecting CSS in DPLC patients (P < 0.05) and were utilized to establish a nomogram. The C-index of the nomogram in the training set was 0.671, and the AUC values of ROC curves for 1-year, 3-year, and 5-year survival rates were 0.84, 0.78, and 0.74, respectively. The C-index of the testing set was 0.644, and the AUC values were 0.72, 0.74, and 0.75, respectively. Calibration curves for both sets were close to the diagonal line, indicating good predictive ability of the nomogram. DCA curves demonstrated the good decision-making ability of the nomogram.

CONCLUSION

This study revealed the clinical features of DPLC patients and developed an effective nomogram for predicting CSS, which can assist clinicians in making accurate and personalized clinical decisions regarding patient treatment.

Design and evaluation of sulfadiazine derivatives as potent dual inhibitors of EGFRWT and EGFRT790M: integrating biological, molecular docking, and ADMET analysis

A series of derivatives (5-14) were synthesized through the diazotization of sulfadiazine with active methylene compounds. The chemical structures of these newly designed compounds were validated through spectral and elemental analysis techniques. The antiproliferative potential of derivatives 5-14 was assessed against three distinct cancer cell lines (A431, A549, and H1975) using the MTT assay. The results revealed that compounds 8, 12, and 14 exhibited the most potent antiproliferative activity, with IC50 values ranging from 2.31 to 7.56 μM. Notably, these values were significantly lower than those of known EGFR inhibitors, including erlotinib, gefitinib, and osimertinib, suggesting the potential of these derivatives as novel antiproliferative agents. Furthermore, compound 12 was identified as the most potent inhibitor of both EGFRWT and EGFRT790M protein kinases, with IC50 values of 14.5 and 35.4 nM, respectively. These results outperformed those of gefitinib and osimertinib, which exhibited IC50 values of 18.2 and 368.2 nM, and 57.8 and 8.5 nM, respectively. Molecular docking studies of compounds 8, 12, and 14 within the ATP-binding sites of both EGFRWT and EGFRT790M corroborated the in vitro results when compared to erlotinib, gefitinib, and osimertinib. The docking results indicated that compound 8 exhibited a favorable binding affinity for both EGFRWT and EGFRT790M, with binding scores of -6.40 kcal mol-1 and -7.53 kcal mol-1, respectively, which were comparable to those of gefitinib and osimertinib, with binding scores of -8.01 and -8.72 kcal mol-1, respectively. Furthermore, an assessment of the most promising EGFR inhibitors (8, 12, and 14) using the egg-boiled method for their in silico ADME properties revealed significant lipophilicity, blood-brain barrier (BBB) penetration, and gastrointestinal (GIT) absorption. Collectively, our designed analogs, particularly compounds 8, 12, and 14, exhibit promising dual antiproliferative and EGFRWT and EGFRT790M kinase inhibitory properties, positioning them as efficient candidates for further therapeutic development.

In vitro evidence for the potential of EGFR inhibitors to decrease the TGF-β1-induced dispersal of circulating tumour cell clusters mediated by EGFR overexpression

Most cancer-related deaths are due to the spread of tumour cells throughout the body-a process known as metastasis. While in the vasculature, these cells are referred to as circulating tumour cells (CTCs) and can be found as either single cells or clusters of cells (often including platelets), with the latter having the highest metastatic potential. However, the biology of CTC clusters is poorly understood, and there are no therapies that specifically target them. We previously developed an in vitro model system for CTC clusters and proposed a new extravasation model that involves cluster dissociation, adherence, and single-cell invasion in response to TGF-β1 released by platelets. Here, we investigated TGF-β1-induced gene expression changes in this model, focusing on genes for which targeted drugs are available. In addition to the upregulation of the TGF-β1 signalling pathway, we found that (i) genes in the EGF/EGFR pathway, including those coding for EGFR and several EGFR ligands, were also induced, and (ii) Erlotinib and Osimertinib, two therapeutic EGFR/tyrosine kinase inhibitors, decreased the TGF-β1-induced adherence and invasion of the CTC cluster-like line despite the line expressing wild-type EGFR. Overall, we suggest that EGFR inhibitors have the potential to decrease the dispersal of CTC clusters that respond to TGF-β1 and overexpress EGFR (irrespective of its status) and thus could improve patient survival.

Synthesis of novel pyrimido[4,5-b]quinoline derivatives as dual EGFR/HER2 inhibitors as anticancer agents

A series of novel N-aryl-5-aryl-6,7,8,9-tetrahydropyrimido[4,5-b]quinolin-4-amines 4a-4l was synthesized as potential anticancer agents through Dimroth rearrangement reaction of intermediates 3a-3c. Pyrimido[4,5-b]quinolines 4a-4l showed promising activity against the Michigan Cancer Foundation-7 (MCF-7) cell line, compared with lapatinib as the reference drug. Compounds 4d, 4h, 4i, and 4l demonstrated higher cytotoxic activity than lapatinib, with IC50 values of 2.67, 6.82, 4.31, and 1.62 µM, respectively. Compounds 4d, 4i, and 4l showed promising epidermal growth factor receptor (EGFR) inhibition with IC50 values of 0.065, 0.116, and 0.052 µM, respectively. These compounds were subjected to human epidermal growth factor receptor 2 (HER2) inhibition and showed IC50 values of 0.09, 0.164, and 0.055 µM, respectively. Compounds 4d, 4i, and 4l are good candidates as dual EGFR/HER2 inhibitors. The most active compound, 4l, was subjected to cell-cycle analysis and induced cell-cycle arrest at the S phase. Compound 4l induced apoptosis 60-fold compared with control untreated MCF-7 cells. 4l can inhibit cancer metastasis. It reduced MCF-7 cell infiltration and metastasis by 45% compared with control untreated cells.

Pyrrolo[2,3-D]Pyrimidines as EGFR and VEGFR Kinase Inhibitors: A Comprehensive SAR Review

Tyrosine kinases are implicated in a wide array of cellular physiological processes, including cell signaling. The discovery of the BCR-ABL tyrosine kinase inhibitor imatinib and its FDA approval in 2001 paved the way for the development of small molecule chemical entities of diverse structural backgrounds as tyrosine kinase inhibitors for the treatment of various ailments. Two of the most prominent tyrosine kinases as drug targets are the epidermal growth factor receptor (EGFR) and the vascular endothelial growth factor receptor (VEGFR), as evidenced by the clinical success of their many inhibitors in the drug market. Among several other physiological roles, EGFR regulates epithelial tissue development and homeostasis, while VEGFR regulates tumor-induced angiogenesis. The pyrrolo[2,3-d]pyrimidine nucleus represents a deaza-isostere of adenine, the nitrogenous base of ATP. The recent introduction of many pyrrolo[2,3-d]pyrimidines to the drug market as tyrosine kinase inhibitors makes them a hot topic in the medicinal chemistry research area at the present time. This review article comprehensively sheds light on the structure-activity relationship (SAR) of pyrrolo[2,3-d]pyrimidines as EGFR and VEGFR tyrosine kinase inhibitors, aiming to provide help medicinal chemists in the design of future pyrrolopyrimidine kinase inhibitors.

Emerging Nanotechnology-based Therapeutics: A New Insight into Promising Drug Delivery System for Lung Cancer Therapy

BACKGROUND

Lung cancer is a foremost global health issue due to its poor diagnosis. The advancement of novel drug delivery systems and medical devices will aid its therapy.

OBJECTIVE

In this review, the authors thoroughly introduce the ideas and methods for improving nanomedicine- based approaches for lung cancer therapy. This article provides mechanistic insight into various novel drug delivery systems (DDSs) including nanoparticles, solid lipid nanoparticles, liposomes, dendrimers, niosomes, and nanoemulsions for lung cancer therapy with recent research work. This review provides insights into various patents published for lung cancer therapy based on nanomedicine. This review also highlights the current status of approved and clinically tested nanoformulations for their treatment.

METHODOLOGY

For finding scholarly related data for the literature search, many search engines were employed including PubMed, Science Direct, Google, Scihub, Google Scholar, Research Gate, Web of Sciences, and several others. Various keywords and phrases were used for the search such as "nanoparticles", "solid lipid nanoparticles", "liposomes", "dendrimers", "niosomes", "nanoemulsions", "lung cancer", "nanomedicine", "nanomaterial", "nanotechnology", "in vivo" and "in vitro". The most innovative and cutting-edge nanotechnology-based approaches that are employed in pre-clinical and clinical studies to address problems associated with lung cancer therapies are also mentioned in future prospects. A variety of problems encountered with current lung cancer therapy techniques that frequently led to inadequate therapeutic success are also discussed in the end.

CONCLUSION

The development of nanoformulations at the pilot scale still faces some difficulties, but their prospects for treating lung cancer appear to be promising in the future. Future developments and trends are anticipated as the evaluation comes to a close.

Role of exosomes in non-small cell lung cancer and EGFR-mutated lung cancer

As an important mediator of information transfer between cells, exosomes play a unique role in regulating tumor growth, supporting vascular proliferation, tumor invasion, and metastasis. Exosomes are widely present in various body fluids, and therefore they can be used as a potential tool for non-invasive liquid biopsy. The present study reviews the role of exosomes in liquid biopsy, tumor microenvironment formation, and epithelial-mesenchymal transition in non-small cell lung cancer (NSCLC). By targeting epidermal growth factor receptor (EGFR) therapy as a first-line treatment for patients with NSCLC, this study also briefly describes the occurrence of EGRF+ exosomes and the role of exosomes and their contents in non-invasive detection and potential therapeutic targets in EGFR-mutated lung cancer.

Thieno[2,3-b]thiophene Derivatives as Potential EGFRWT and EGFRT790M Inhibitors with Antioxidant Activities: Microwave-Assisted Synthesis and Quantitative In Vitro and In Silico Studies

Microwave-assisted synthesis and spectral analysis of certain novel derivatives of 3,4-diaminothieno[2,3-b]thiophene-2,5-dicarbonitrile 1-7 were carried out. Compounds 1-7 were examined for cytotoxicity against MCF-7 and A549 cell lines using the quantitative MTT method, and gefitinib and erlotinib were used as reference standards. Compounds 1-7 were shown to be more active than erlotinib against the two cell lines tested. Compound 2 outperformed regular erlotinib by 4.42- and 4.12-fold in MCF-7 and A549 cells, respectively. The most cytotoxic compounds were subsequently studied for their suppression of kinase activity using the homogeneous time-resolved fluorescence assay versus epidermal growth factor receptor (EGFR^WT) and EGFR^790M. With IC₅₀ values of 0.28 ± 0.03 and 5.02 ± 0.19, compound 2 was demonstrated to be the most effective against both forms of EGFR. Furthermore, compound 2 also had the best antioxidant property, decreasing the radical scavenging activity by 78%. Molecular docking research, on the other hand, was carried out for the analyzed candidates (1-7) to study their mechanism of action as EGFR inhibitors. In silico absorption, distribution, metabolism, excretion, and toxicity tests were also performed to explain the physicochemical features of the examined derivatives.

Advanced diagnostic and therapeutic strategies in nanotechnology for lung cancer

As a highly invasive thoracic malignancy with increasing prevalence, lung cancer is also the most lethal cancer worldwide due to the failure of effective early detection and the limitations of conventional therapeutic strategies for advanced-stage patients. Over the past few decades, nanotechnology has emerged as an important technique to obtain desired features by modifying and manipulating different objects on a molecular level and gained a lot of attention in many fields of medical applications. Studies have shown that in lung cancer, nanotechnology may be more effective and specific than traditional methods for detecting extracellular cancer biomarkers and cancer cells in vitro, as well as imaging cancer in vivo; Nanoscale drug delivery systems have developed rapidly to overcome various forms of multi-drug resistance and reduce detrimental side effects to normal tissues by targeting cancerous tissue precisely. There is no doubt that nanotechnology has the potential to enhance healthcare systems by simplifying and improving cancer diagnostics and treatment. Throughout this review, we summarize and highlight recent developments in nanotechnology applications for lung cancer in diagnosis and therapy. Moreover, the prospects and challenges in the translation of nanotechnology-based diagnostic and therapeutic methods into clinical applications are also discussed.

The emerging role of circular RNAs in drug resistance of non-small cell lung cancer

Due to the characteristics of aggressiveness and high risk of postoperative recurrence, non-small cell lung cancer (NSCLC) is a serious hazard to human health, accounting for 85% of all lung cancer cases. Drug therapies, including chemotherapy, targeted therapy and immunotherapy, are effective treatments for NSCLC in clinics. However, most patients ultimately develop drug resistance, which is also the leading cause of treatment failure in cancer. To date, the mechanisms of drug resistance have yet to be fully elucidated, thus original strategies are developed to overcome this issue. Emerging studies have illustrated that circular RNAs (circRNAs) participate in the generation of therapeutic resistance in NSCLC. CircRNAs mediate the modulations of immune cells, cytokines, autophagy, ferroptosis and metabolism in the tumor microenvironment (TME), which play essential roles in the generation of drug resistance of NSCLC. More importantly, circRNAs function as miRNAs sponges to affect specific signaling pathways, directly leading to the generation of drug resistance. Consequently, this review highlights the mechanisms underlying the relationship between circRNAs and drug resistance in NSCLC. Additionally, several therapeutic drugs associated with circRNAs are summarized, aiming to provide references for circRNAs serving as potential therapeutic targets in overcoming drug resistance in NSCLC.

Microwave-assisted synthesis, spectroscopic characterization, and biological evaluation of fused thieno[2,3-d]pyrimidines as potential anti-cancer agents targeting EGFRWT and EGFRT790M

Epidermal growth factor receptor (EGFR) is a transmembrane protein tyrosine kinase that is usually overexpressed in many types of cancers. In the present study, an effort was done in synthesis of new 3,4-diaminothieno[2,3-b] thiophene-2,5-dicarbonitrile derivatives 2-8, assisted by a microwave device. Different spectroscopic instruments were used for their analysis and confirmed their chemical structures. The antimicrobial properties of the produced compounds were investigated and found to be promising. Next, they were tested for cytotoxicity against MCF-7, HepG-2, HCT-116, and A549 cell lines. Moreover, in vitro cytotoxicity evaluation against well-known standards, namely, gefitinib and erlotinib was achieved using MTT method. The obtained compounds (2-8) were found to be more effective against the two tested cancer cell lines than erlotinib. In MCF-7 and A549 cells, compound 3 was found to be 4.42 and 4.12 times more active than erlotinib, respectively. The activity of radical scavenging was inhibited by 78%. The most cytotoxic compounds were subsequently studied for their kinase inhibitory effect against EGFR^WT and EGFR^T790M using the HTRF assay. Compound 3 was shown to be the most powerful against both kinds of EGFR, with IC₅₀ values of 0.28 and 5.02. Furthermore, compound 2 demonstrated the highest antioxidant activity as it has a radical scavenging activity of 78%. Compounds 2,6,7 and 8 revealed to be the most safe compounds, none hepatotoxic, none carcinogenic, none immunotoxic, none mutagenic and none cytotoxic.

Dual target inhibitors based on EGFR: Promising anticancer agents for the treatment of cancers (2017-)

The EGFR family play a significant role in cell signal transduction and their overexpression is implicated in the pathogenesis of numerous human solid cancers. Inhibition of the EGFR-mediated signaling pathways by EGFR inhibitors is a widely used strategy for the treatment of cancers. In most cases, the EGFR inhibitors used in clinic were only effective when the cancer cells harbored specific activating EGFR mutations which appeared to preserve the ligand-dependency of receptor activation but altered the pattern of downstream signaling pathways. Moreover, cancer is a kind of multifactorial disease, and therefore manipulating a single target may result in treatment failure. Although drug combinations for the treatment of cancers proved to be successful, the use of two or more drugs concurrently still was a challenge in clinical therapy owing to various dose-limiting toxicities and drug-drug interactions caused by pharmacokinetic profiles changed. Therefore, a single drug targeting two or multiple targets could serve as an effective strategy for the treatment of cancers. In recent, drugs with diverse pharmacological effects have been shown to be more advantageous than combination therapies due to their lower incidences of side effects and more resilient therapies. Accordingly, dual target-single-agent strategy has become a popular field for cancer treatment, and researchers became more and more interest in the development of novel dual-target drugs in recent years. In this review, we briefly introduce the EGFR family proteins and synergisms between EGFR and other anticancer targets, and summarizes the development of potential dual target inhibitors based on wild-type and/or mutant EGFR for the treatment of solid cancers in the past five years. Additionally, the rational design and SARs of these dual target agents are also presented in detailed, which will lay a significant foundation for the further development of novel EGFR-based dual inhibitors with excellent druggability.

Targeted Therapies in Lung Cancers: Current Landscape and Future Prospects

BACKGROUND

Lung cancer is the most common and malignant cancer worldwide. Targeted therapies have emerged as a promising treatment strategy for lung cancers.

OBJECTIVE

The objective of this study is to evaluate the current landscape of targets and finding promising targets for future new drug discovery for lung cancers by identifying the science-technology-clinical development pattern and mapping the interaction network of targets.

METHODS

Targets for cancers were classified into 3 groups based on a paper published in Nature. We search for scientific literature, patent documents and clinical trials of targets in Group 1 and Group 2 for lung cancers. Then, a target-target interaction network of Group 1 was constructed, and the science-technology-clinical(S-T-C) development patterns of targets in Group 1 were identified. Finally, based on the cluster distribution and the development pattern of targets in Group 1, interactions between the targets were employed to predict potential targets in Group 2 on drug development.

RESULTS

The target-target interaction(TTI)network of group 1 resulted in 3 clusters with different developmental stages. The potential targets in Group 2 are divided into 3 ranks. Level-1 is the first priority and level-3 is the last. Level-1 includes 16 targets, such as STAT3, CRKL, and PTPN11, that are mostly involved in signaling transduction pathways. Level-2 and level-3 contain 8 and 6 targets related to various biological functions.

CONCLUSION

This study will provide references for drug development in lung cancers, emphasizing that priorities should be given to targets in Level-1, whose mechanisms are worth further exploration.

Tumor-derived exosomal circRNA_102481 contributes to EGFR-TKIs resistance via the miR-30a-5p/ROR1 axis in non-small cell lung cancer

Exosomes are messengers for intercellular communication and signal transduction. Circular RNA (circRNA) abnormal expression and regulation are involved in the occurrence and development of a variety of tumors. In the present study, exosomes in the serum of five patients with non-small cell lung cancer (NSCLC) were isolated before and after EGFR-TKIs resistance, and the circRNA expression profile was screened using a circRNA microarray. The effects of the exosome circRNA_102481 on cell proliferation and apoptosis were analyzed. The interaction between miR-30a-5p and circRNA_102481 or ROR1 was predicted by starBase software, and was confirmed by RNA pull-down and dual-luciferase reporter assays. The results showed that exosomes containing circRNA_102481 were significantly up-regulated in NSCLC with EGFR-TKIs resistance (p<0.05), and that circRNA_102481 was mainly secreted by EGFR-TKIs resistance cell via exosomes (p<0.05). Both circRNA_102481 silencing and si-circRNA_102481 transported by exosomes could inhibit EGFR-TKIs resistance cell proliferation and promote cell apoptosis and circRNA_102481 overexpression could promote EGFR-TKIs sensitive cell proliferation and inhibit cell apoptosis in vitro (p<0.05). CircRNA_102481 served as a miR-30a-5p sponge to regulate ROR1 expression (p<0.05). Furthermore, the expression of circRNA_102481 in exosomes was associated with TNM stage, tumor differentiation status, brain metastasis, and PFS and OS duration. Therefore, it was concluded that tumor-derived exosomal circRNA_ 102481 could contribute to EGFR-TKIs resistance via the microRNA-30a-5p/ROR1 axis in NSCLC. Exosomal circRNA_102481 may serve as a novel diagnostic biomarker and a therapeutic target for EGFR-TKIs resistance in NSCLC.

Phase I results of S49076 plus gefitinib in patients with EGFR TKI-resistant non-small cell lung cancer harbouring MET/AXL dysregulation

BACKGROUND

MET and AXL dysregulation is reported as a bypass mechanism driving tumour progression in non-small cell lung cancer (NSCLC) with acquired resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI). This non-comparative phase I study investigated the combination of gefitinib with S49076, a MET/AXL inhibitor, in advanced EGFR TKI-resistant NSCLC patients with MET and/or AXL dysregulation.

METHODS

Patients received S49076 at escalating doses of 500 or 600 mg with a fixed dose of 250 mg gefitinib orally once daily in continuous 28day cycles. MET and AXL dysregulation and EGFR/T790M mutation status were centrally assessed in tumour biopsies at screening. Tumour response was evaluated using Response Evaluation Criteria in Solid Tumors (RECIST). EGFR TKI resistance mechanisms were analysed by next-generation sequencing. The clonal evolution of tumours was monitored with the analysis of circulating tumour DNA.

RESULTS

Of 92 pre-screened patients, 22 met the molecular inclusion criteria and 14 were included. The recommended dose was 600 mg daily S49076. Best overall responses were 2 partial responses (1 patient with MET dysregulation only, 1 MET and AXL co-dysregulation) and 8 patients with stable disease. Other potential concomitant mechanisms of resistance to EGFR TKI were identified in more than half of the included patients.

CONCLUSIONS

S49076 plus gefitinib demonstrated a good tolerability with limited anti-tumour activity. Due to the low number of eligible patients, no tendency in term of activity appeared in any specific molecular subset and the data did not allow for identification of AXL overexpression as an oncogenic driver.

Serum exosomal microRNAs as predictive markers for EGFR mutations in non-small-cell lung cancer

Background

Current therapeutic drugs show positive effects on non–small‐cell lung cancer (NSCLC) patients with mutant epidermal growth factor receptor (EGFR) expression, whereas a lesser beneficial effect is generally noted on NSCLC patients with wild‐type EGFR. Therefore, identification of new detection methods for the accurate clinical diagnosis of NSCLC is essential.

Methods

In this study, tumor‐derived exosomes from the plasma of EGFR mutation and wild‐type NSCLC patients were isolated. Extensive exosomal miRNA profiling of EGFR mutation and wild‐type NSCLC patients, in comparison with healthy individuals, was performed using miRNA‐sequencing analysis.

Results

The variation of exosomal miRNA expression between control group (NR) and NCSLC samples (AM and AW) was identified. 96 significantly different expressed miRNAs were identified. Of these, 39 miRNAs were upregulated and 57 were downregulated. 11 miRNAs were downregulated, and 31 miRNAs were upregulated in the miRNA expression between NR and AM. Compared with healthy donors, 54 upregulated miRNAs and 36 downregulated miRNAs were observed in samples from AW patients. 40 different expressed miRNAs were identified in AM samples, compared with AW. Ten of upregulated miRNAs are miR‐260, miR‐1169, miR‐117, miR‐15b‐5p, miRNA‐731, miR‐342‐5p, miR‐ 898, miR‐1384, miR‐56, and miR‐1214. Ten of downregulated miRNAs are miR‐99b‐5p, miR‐1116, miR‐689, miR‐818, miR‐604, miR‐72, miR‐955, miR‐403, miR‐1228, and miR‐836.

Conclusion

The exosomal miR‐1169 and miR‐260 as potential candidates, which contain specific characteristics that can distinguish between wild‐type EGFR and mutant EGFR NSCLC patients in early‐stage cancers.

Formation of an RNA Quadruplex-Duplex Hybrid in Living Cells between mRNA of the Epidermal Growth Factor Receptor (EGFR) and a G-Rich Antisense Oligoribonucleotide

Antisense DNA oligonucleotides, short interfering RNAs (siRNAs), and CRISPR/Cas9 genetic tools are the most useful therapeutic nucleic acids regulating gene expression based on the antisense specificity towards messenger RNA. Here, we present an effective novel strategy for inhibiting translation based on the antisense-controlled formation of an RNA quadruplex-duplex hybrid (QDH) between a G-rich RNA antisense oligoribonucleotide (Q-ASO) and specific mRNA, comprising two distant G-tracts. We selected epidermal growth factor receptor (EGFR) as a well-established target protein in anticancer therapy. The chemically modified, bi-functional anti-EGFR Q-ASO and a 56-nt long EGFR mRNA fragment, in the presence of potassium ions, were shown to form in vitro very stable parallel G-quadruplex containing a 28-nt long external loop folding to two duplex-stem structure. Besides, the Q-ASOs effectively reduced EGFR mRNA levels compared to the non-modified RNA and DNA antisense oligonucleotides (rASO, dASO). In addition, the hybridization specificity of Q-ASO comprising a covalently attached fluorescent tag was confirmed in living cells by visualization of the G4 green fluorescent species in the presence of other antisense inhibitors under competitive conditions. The results presented here offer novel insights into the potential application of Q-ASOs for the detection and/or alteration of (patho)biological processes through RNA:RNA quadruplex-duplex formation in cellular systems.

Saikosaponin D inhibits proliferation and induces apoptosis of non-small cell lung cancer cells by inhibiting the STAT3 pathway

OBJECTIVE

To study the effects of saikosaponin D (SSD) on proliferation and apoptosis in human non-small cell lung cancer cell lines, and to explore underlying mechanisms.

METHODS

Following treatment with saikosaponin D, A549 and H1299 cells were assessed for anti-proliferation effects using cell cycle kit-8 assays, changes in nuclear morphology using 4',6-diamidino-2-phenylindole (DAPI) staining, and cell apoptosis using annexin V/propidium iodide double staining. Proliferation- and apoptosis-related proteins were detected by immunoblotting.

RESULTS

Saikosaponin D had dose-dependent inhibitory effects on A549 cells (IC₅₀, 3.57 µM) and H1299 cells (IC₅₀, 8.46 µM). DAPI staining revealed decreased cell numbers, and most H1299 cells became round after treatment with 20 µM saikosaponin D. As saikosaponin D concentration increased, the proportions of cells in G0/G1 phase, and cells undergoing apoptosis, increased. Levels of phosphorylated p44/42 and signal transducer and activator of transcription (STAT)3 were significantly downregulated in both cell lines, while total STAT3 levels were not significantly affected. The cleaved form of caspase 3 was significantly upregulated.

CONCLUSIONS

Saikosaponin D inhibits proliferation, inducing cell cycle arrest and apoptosis, in lung cancer cells in a dose-dependent manner, possibly through inhibition of STAT3 phosphorylation and activation of caspase 3.

[Advances of Exosomes Extraction and Its Mechanism in Early Diagnosis of Lung Cancer]

肺癌是世界范围内发病率和死亡率较高的恶性肿瘤之一，严重威胁着国民的生命安全与健康。肺癌的早期诊断是肺癌预防和治疗过程中的关键环节，对肺癌进行早期诊断有利于提高患者的生存率。外泌体(exosomes)与肿瘤的侵袭与转移过程密切相关，在肺癌的发生发展过程中，外泌体发挥着重要的调控作用。近年来，以外泌体为载体的生物标记物成为肺癌强有力的诊断工具。外泌体是一种由细胞分泌的由膜包裹的大小均一、直径约为30 nm-200 nm的脂质双分子层结构小囊泡。外泌体的内容物包含不同类型的核酸和蛋白质，这些核酸和蛋白质来源于其亲本细胞(包括亲本癌细胞)，具有广泛的生理功能，包括参与免疫调节、细胞间联络等。外泌体中的生物大分子物质，如单链RNA、长非编码RNA、微小RNA(microRNA, miRNA)、蛋白质以及脂类，可以为肺癌的早期临床诊断提供有价值的信息。因此，本文就外泌体的来源、结构特点、提取方法、生物学特性和在肺癌早期诊断中的作用研究进展做简要阐述。

In Vitro Inhibition of Human Aldehyde Oxidase Activity by Clinically Relevant Concentrations of Gefitinib and Erlotinib: Comparison with Select Metabolites, Molecular Docking Analysis, and Impact on Hepatic Metabolism of Zaleplon and Methotrexate

Gefitinib and erlotinib are epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) with activity against metastatic non-small cell lung cancer. Aldehyde oxidase-1 (AOX1) is a cytosolic drug-metabolizing enzyme. We conducted an experimental and molecular docking study on the effect of gefitinib, erlotinib, and select metabolites on the in vitro catalytic activity of AOX1, as assessed by carbazeran 4-oxidation, and determined the impact of AOX1 inhibition on hepatic metabolism of zaleplon and methotrexate. Gefitinib, desmorpholinopropylgefitinib, erlotinib, desmethylerlotinib, and didesmethylerlotinib inhibited human hepatic cytosolic carbazeran 4-oxidation by a competitive mode, with inhibition constants in submicromolar or low micromolar concentrations. Desmethylgefitinib did not affect AOX1 catalytic activity. A similar pattern was obtained when investigated with human kidney cytosol or recombinant AOX1. The differential effect of gefitinib on human, rat, and mouse hepatic AOX1 catalytic activity suggests species-dependent chemical inhibition of AOX1. Erlotinib was considerably more potent than gefitinib in decreasing hepatic cytosolic zaleplon 5-oxidation and methotrexate 7-oxidation. Molecular docking analyses provided structural insights into the interaction between EGFR-TKIs and AOX1, with key residues and bonds identified, which provided favorable comparison and ranking of potential inhibitors. Based on the US Food and Drug Administration guidance to assess the risk of drug-drug interactions, the calculated R1 values indicate that further investigations are warranted to determine whether gefitinib and erlotinib impact AOX1-mediated drug metabolism in vivo. Overall, erlotinib desmethylerlotinib, didesmethylerlotinib, gefitinib, and desmorpholinopropylgefitinib are potent inhibitors of human AOX1 catalytic function and hepatic metabolism of zaleplon and methotrexate, potentially affecting drug efficacy or toxicity. SIGNIFICANCE STATEMENT: As epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs), gefitinib and erlotinib are first-line pharmacotherapy for metastatic non-small cell lung cancer. Our experimental findings indicate that clinically relevant concentrations of gefitinib, desmorpholinopropylgefitinib, erlotinib, desmethylerlotinib, and didesmethylerlotinib, but not desmethylgefitinib, inhibit human aldehyde oxidase (AOX1) catalytic activity and hepatic cytosolic metabolism of zaleplon and methotrexate. Molecular docking analysis provide structural insights into the key AOX1 interactions with these EGFR-TKIs. Our findings may trigger improved strategies for new EGFR-TKI design and development.

Design, synthesis, biological evaluation, QSAR analysis and molecular modelling of new thiazol-benzimidazoles as EGFR inhibitors

Heterocyclic rings such as thiazole and benzimidazole are considered as privileged structures, since they constitute several FDA-approved drugs for cancer treatment. In this work, a new set of 2-(2-(substituted) hydrazinyl)-4-(1-methyl-1H-benzo[d]imidazol-2-yl) thiazoles 4a-q were designed as epidermal growth factor receptor (EGFR) inhibitors and synthesized using concise synthetic methods. The new target compounds have been evaluated in vitro for their suppression activity against EGFR TK. Compounds 4n, 4h, 4i, 4a and 4d exhibited significant potency in comparison with erlotinib which served as a reference drug (IC50, 71.67-152.59 nM; IC50 erlotinib, 152.59 nM). Furthermore, MTT assay revealed that compounds 4j, 4a, 4f, 4h, 4n produced the most promising cytotoxic potency against the human breast cancer cell line (MCF-7) (IC50; 5.96-11.91 µM; IC50 erlotinib; 4.15 µM). Compound 4a showed promising activity as EGFR TK inhibitor as well as anti-breast cancer agent. In addition, 4a induced apoptotic effect and cell cycle arrest at G2/M phase preventing the mitotic cycle in MCF-7 cells. Moreover, 4a upregulated the oncogenic parameters; caspase-3, p53, Bax/Bcl-2 as well as it inhibited the level of PARP-1 enzyme. QSAR study was carried out for the new derivatives and it revealed the goodness of the models. Furthermore, molecular docking studies represented the binding modes of the promising compounds in the active pocket of EGFR.

EGFR mutation status in a series of Turkish non-small cell lung cancer patients

Epidermal growth factor receptor (EGFR) mutations are potential markers driving carcinogenesis, and may alter the response to EGFR tyrosine kinase inhibitors in patients with non-small cell lung cancer (NSCLC). The frequency of EGFR mutations in patients with NSCLC differs according to sex, smoking habits and regional-based ethnicity differences. The aim of the present study was to determine the frequency of EGFR mutations in Turkish patients with NSCLC to highlight the importance of regional differences, and their associations with patient characteristics. Genomic DNA was extracted from formalin-fixed and paraffin-embedded tumor tissue sections of 409 NSCLC patients. The most common EGFR mutations in exons 18, 19, 20 and 21 were detected using BioFilmChip-based microarray assay. The overall EGFR mutation frequency was 16.6%, and the highest mutation frequencies were observed in exon 19 (6.4%) and exon 21 (7.3%). There was a higher frequency of EGFR mutations in females compared with males and in never-smokers compared with smokers (both P≤0.05). These results were similar to other European population-based studies, but not consistent Middle-Eastern based studies. The present study may contribute to understanding the gradient frequency of EGFR mutation across different ethnicities, and in designing genome wide-based collaborations that may reveal novel decision making and susceptibility mutations in EGFR in patients with NSCLC.