Paeoniae radix overcomes resistance to EGFR-TKIs via aurora B pathway suppression in lung adenocarcinoma.

Targeted therapies using epidermal growth factor receptor (EGFR) inhibitors have markedly improved survival rates and quality of life for patients with EGFR-mutant lung adenocarcinoma (LUAD). Despite these advancements, resistance to EGFR inhibitors remains a significant challenge, limiting the overall effectiveness of the treatment. This study explored the synergistic effects of combining Paeoniae Radix (PR) with first-generation EGFR-tyrosine kinase inhibitors (TKIs), erlotinib and gefitinib, to overcome this resistance. Transcriptomic analysis of EGFR-mutant LUAD cell lines revealed that PR treatment could potentially reverse the gene signatures associated with resistance to EGFR-TKIs, primarily through the suppression of the Aurora B pathway. Experimental validation demonstrated that combining PR with erlotinib and gefitinib enhanced drug responsiveness by inhibiting Aurora kinase activity and inducing apoptosis in LUAD cells. Additionally, gene expression changes confirmed these combined effects, with the suppression of the Aurora B pathway and upregulation of the apoptotic pathway, which was accompanied by increased expression of multiple pro-apoptotic genes. Our findings contribute to the development of natural product-based therapeutic strategies to mitigate drug resistance in LUAD.

Piperlongumine in combination with EGFR tyrosine kinase inhibitors for the treatment of lung cancer cells.

Objectives: EGFR tyrosine kinase inhibitor (EGFR-TKI) therapies such as erlotinib and gefitinib are approved for the treatment of non-small cell lung cancer (NSCLC). However, the high incidence of acquired resistance to these EGFR-TKIs may preclude their effectiveness. Piperlongumine (PPL), an extract from the long pepper fruit (Piper longum), has been shown to possess anticancer properties. The purpose of the study was to investigate piperlongumine as an anticancer agent and to study a combination treatment approach with EGFR-TKIs against lung cancer cells. Methods: Anticancer efficacy of PPL, erlotinib (ERL), gefitinib (GEF), and cisplatin (CIS) were investigated in H1299 and H1975 cell lines. Cells were treated with PPL, ERL, GEF, and CIS alone, and in combination, cell viability was determined after 72 h. The mechanism of PPL-induced cytotoxicity was investigated via reactive oxygen species (ROS) induction, and apoptosis induction using acridine orange/ethidium bromide staining and flow cytometry. The effect of treatment on EGFR-mediated oncogenic signaling was investigated by immunoblotting for mitogenic and apoptotic markers. Results: PPL exhibited a potent cytotoxic effect in H1299 and H1975 cells compared to ERL, GEF, and CIS. Combination treatments of PPL with GEF and ERL showed significant reductions in cancer cells compared to control in both cell lines, which were associated with apoptotic induction, but without significant ROS induction. Compared to control, PPL with GEF significantly increased apoptotic cell death in H1975as confirmed with flow cytometry. Treatment with PPL alone and in combination induced anti-mitogenic and apoptotic responses at the molecular level. Conclusion: PPL sensitized lung cancer cells to EGFR-TKI and induced potent cytotoxic effects at low concentrations.

Precision-cut liver slices as an ex vivo model to evaluate antifibrotic therapies for liver fibrosis and cirrhosis.

BACKGROUND: Considering the lack of successful treatment options and poor prognosis for cirrhosis and cirrhosis-induced HCC, new platforms to investigate antifibrotic therapies are urgently needed. Precision-cut liver slice (PCLS) is a powerful ex vivo culture model that can supplement and potentially replace the traditional models. METHODS: PCLS were prepared from 4 different murine cirrhotic models (choline-deficient, l-amino acid-defined, high-fat diet, thioacetamide, diethylnitrosamine, and carbon tetrachloride) and compared with in vivo murine experiments, in vitro hepatic stellate cells, and human cirrhotic PCLS. RESULTS: PCLS viability in culture was stable for 72 hours. Treatment of erlotinib, an EGF receptor inhibitor, significantly inhibited profibrogenic gene expressions in PCLS from choline-deficient, l-amino acid-defined, high-fat diet or thioacetamide-induced cirrhotic rats. Erlotinib treatment of PCLS from diethylnitrosamine or carbon tetrachloride-induced cirrhotic rats inhibited the expression of profibrogenic genes, which was consistent with the impact of erlotinib on these genes in in vivo diethylnitrosamine or carbon tetrachloride-induced cirrhosis. In addition, in hepatic stellate cells at PCLS from normal mice, erlotinib treatment inhibited TGF-ß1-upregulated expression of Acta2. Similar expression results were observed in in vitro hepatic stellate cells. Expression of key regulators of fibrosis progression and regression were also significantly altered. Changes in profibrogenic gene expression under erlotinib treatment were also corroborated with human cirrhotic PCLS. CONCLUSIONS: Responses to antifibrotic interventions can be detected and quantified with PCLS at the gene expression level. The antifibrotic effects of erlotinib are consistent between PCLS models of murine cirrhosis and those observed in vivo and in vitro. These results were verified in human cirrhotic PCLS. PCLS is an excellent model for assessing antifibrotic therapies that are aligned with the principles of replacement, reduction, and refinement (3Rs), and it will benefit preclinical and clinical research for human fibrosis and cirrhosis.

Erlotinib regulates short-term memory, tau/Aß pathology, and astrogliosis in mouse models of AD.

Introduction: Erlotinib is an epidermal growth factor receptor (EGFR) inhibitor that is approved by the FDA to treat non-small cell lung cancer (NSCLC). Several membrane receptors, including EGFR, interact with amyloid ß (Aß), raising the possibility that erlotinib could have therapeutic effects on Alzheimer's disease (AD). However, the effects of erlotinib on Aß/tau-related pathology and cognitive function in mouse models of AD and its mechanisms of action have not been examined in detail. Methods: To investigate the effects of erlotinib on cognitive function and AD pathology, 3 to 6-month-old PS19 mice and 3 to 3.5-month-old 5xFAD mice and WT mice were injected with vehicle (5% DMSO + 10% PEG + 20% Tween80 + 65% D.W.) or erlotinib (20 mg/kg, i.p.) daily for 14 or 21 days. Then, behavioral tests, Golgi staining, immunofluorescence staining, western blotting ELISA, and real-time PCR were conducted. Results and discussion: We found that erlotinib significantly enhanced short-term spatial memory and dendritic spine formation in 6-month-old P301S tau transgenic (PS19) mice. Importantly, erlotinib administration reduced tau phosphorylation at Ser202/Thr205 (AT8) and Thr231 (AT180) and further aggregation of tau into paired helical fragments (PHFs) and neurofibrillary tangles (NFTs) in 3-month-old and/or 6-month-old PS19 mice by suppressing the expression of the tau kinase DYRK1A. Moreover, erlotinib treatment decreased astrogliosis in 6-month-old PS19 mice and reduced proinflammatory responses in primary astrocytes (PACs) from PS19 mice. In 3- to 3.5-month-old 5xFAD mice, erlotinib treatment improved short-term spatial memory and hippocampal dendritic spine number and diminished Aß plaque deposition and tau hyperphosphorylation. Furthermore, erlotinib-treated 5xFAD mice exhibited significant downregulation of astrocyte activation, and treating PACs from 5xFAD mice with erlotinib markedly reduced cxcl10 (reactive astrocyte marker) and gbp2 (A1 astrocyte marker) mRNA levels and proinflammatory cytokine mRNA and protein levels. Taken together, our results suggest that erlotinib regulates tau/Aß-induced AD pathology, cognitive function, and Aß/tau-evoked astrogliosis and therefore could be a potent therapeutic drug for ameliorating AD symptoms.

Efficacy on symptoms and mortality day vs. night administration of EGFR-TKIs for advanced non-small cell lung cancer.

PURPOSE: This study has a purpose to investigate the side effects of three EGFR-TKIs targeted therapeutic agents (gefitinib, erlotinib, and afatinib) and all-cause mortality in patients with metastatic lung cancer. METHODS: We performed a prospective cohort study. We selected all patients with newly diagnosed metastatic lung cancer between January and November 2019. Main exposure was daytime versus nighttime use of targeted EGFR TKIs. The study outcome was a symptom change using the mobile application, and all-cause mortality between January 2019 and March 2023. RESULTS: Among the 87 study participants, 35 (40%) took their medication at night. Among the 87 study participants, 35 (40%) took their medication at night. At 6 weeks of treatment, acne (1.36; 95% confidence interval [CI] 1.09, 1.64; p for interaction = 0.04) and dry skin (1.35; 95% CI 1.09, 1.61, p for interaction = 0.01) in the day group showed a much increase from baseline compared to the night group. In contrast, the night group reported greater reductions in lung cancer-related symptoms from baseline compared to the day. During follow-up (median 43 months), the night group had a lower risk of all-cause death than the day group, especially in younger patients (adjusted hazard ratio = 0.34; 95% CI 0.13, 0.87). CONCLUSIONS: The group taking EGFR-TKIs at night experienced fewer side effects and had longer overall survival compared to the day group. Clinicians should consider recommending that lung cancer patients take their once-daily oral anticancer drugs in the evening rather than the morning to improve treatment outcomes.

In vitro evidence for the potential of EGFR inhibitors to decrease the TGF-ß1-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-ß1 released by platelets. Here, we investigated TGF-ß1-induced gene expression changes in this model, focusing on genes for which targeted drugs are available. In addition to the upregulation of the TGF-ß1 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-ß1-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-ß1 and overexpress EGFR (irrespective of its status) and thus could improve patient survival.

Macrophage-induced Expression of TonEBP/NFAT5 Is Associated With Gefitinib Resistance and Migration in PC-9 Cells.

BACKGROUND/AIM: Macrophages prevail in the microenvironment of several tumors, including non-small-cell lung cancer (NSCLC), where they secrete pro-tumorigenic factors that contribute to cancer progression. This study investigated the role of macrophages on the resistance of epidermal growth factor receptor (EGFR)-mutated NSCLC cells to tyrosine kinase inhibitors (TKIs). MATERIALS AND METHODS: EGFR-mutated cell lines PC-9 and HCC827 were cocultured with macrophages and treated with TKIs (erlotinib and gefitinib). The effects of the macrophage-conditioned medium (macrophage CM) on gefitinib resistance and cell migration were also evaluated. RESULTS: Co-culture with macrophages significantly enhanced the resistance to erlotinib and gefitinib in PC-9 and HCC827 cells compared to that in cells cultured independently. Macrophage CM markedly induced gefitinib resistance in PC-9 cells, with maximum resistance observed at 50% CM concentration. This resistance persisted for up to 48 h post-CM removal. Macrophage CM inhibited gefitinib-induced apoptosis, as evidenced by the decreased expression of cleaved caspase-3, PARP, and BIM. Additionally, macrophage CM increased the migration ability of PC-9 cells, as shown by the wound healing and transwell migration assays. Studies have shown that TonEBP is crucial in cancer metastasis and drug resistance; we found that inhibition of TonEBP/NFAT5 expression reduced gefitinib resistance and migration in macrophage CM-induced PC-9 cells, indicating its role as mediator of these effects. CONCLUSION: Macrophages contribute to TKI resistance and enhance the migration of EGFR-mutated NSCLC cells through mechanisms involving TonEBP/NFAT5. Therefore, targeting TonEBP/NFAT5 represents a potential therapeutic strategy for overcoming macrophage-induced TKI resistance in NSCLC cells.

Combination of monensin and erlotinib synergistically inhibited the growth and cancer stem cell properties of triple-negative breast cancer by simultaneously inhibiting EGFR and PI3K signaling pathways.

BACKGROUND: Cancer stem cells (CSCs) in triple-negative breast cancer (TNBC) are recognized as a highly challenging subset of cells, renowned for their heightened propensity for relapse and unfavorable prognosis. Monensin, an ionophoric antibiotic, has been reported to exhibit significant therapeutic efficacy against various cancers, especially CSCs. Erlotinib is classified as one of the EGFR-TKIs and has been previously identified as a promising therapeutic target for TNBC. Our research aims to assess the effectiveness of combination of monensin and erlotinib as a potential treatment strategy for TNBC. METHODS: The combination of monensin and erlotinib was assessed for its potential anticancer activity through various in vitro assays, including cytotoxicity assay, colony formation assay, wound healing assay, transwell assay, mammosphere formation assay, and proportion of CSCs assay. Additionally, an in vivo study using tumor-bearing nude mice was conducted to evaluate the inhibitory effect of the monensin and erlotinib combination on tumor growth. RESULTS: The results indicated that combination of monensin with erlotinib synergistically inhibited cell proliferation, the migration rate, the invasion ability and decreased the CSCs proportion, and CSC markers SOX2 and CD133 in vivo and in vitro. Furthermore, the primary proteins involved in the signaling pathways of the EGFR/ERK and PI3K/AKT are simultaneously inhibited by the combination treatment of monensin and erlotinib in vivo and in vitro. CONCLUSIONS: The simultaneous inhibition of the EGFR/ERK and PI3K/AKT/mTOR signaling pathways by the combination of monensin and erlotinib exhibited a synergistic effect on suppressing tumor proliferation and cancer cell stemness in TNBC.

Functional genomics reveals an off-target dependency of drug synergy in gastric cancer therapy.

BACKGROUND: Integrating molecular-targeted agents into combination chemotherapy is transformative for enhancing treatment outcomes in cancer. However, realizing the full potential of this approach requires a clear comprehension of the genetic dependencies underlying drug synergy. While the interactions between conventional chemotherapeutics are well-explored, the interplay of molecular-targeted agents with conventional chemotherapeutics remains a frontier in cancer treatment. Hence, we leveraged a powerful functional genomics approach to decode genomic dependencies that drive synergy in molecular-targeted agent/chemotherapeutic combinations in gastric adenocarcinoma, addressing a critical need in gastric cancer therapy. METHODS: We screened pharmacological interactions between fifteen molecular-targeted agent/conventional chemotherapeutic pairs in gastric adenocarcinoma cells, and examined the genome-scale genetic dependencies of synergy integrating genome-wide CRISPR screening with the shRNA-based signature assay. We validated the synergy in cell death using fluorescence-based and lysis-dependent inference of cell death kinetics assay, and validated the genetic dependencies by single-gene knockout experiments. RESULTS: Our combination screen identified SN-38/erlotinib as the drug pair with the strongest synergism. Functional genomics assays unveiled a genetic dependency signature of SN-38/erlotinib identical to SN-38. Remarkably, the enhanced cell death with improved kinetics induced by SN-38/erlotinib was attributed to erlotinib's off-target effect, inhibiting ABCG2, rather than its on-target effect on EGFR. CONCLUSION: In the era of precision medicine, where emphasis on primary drug targets prevails, our research challenges this paradigm by showcasing a robust synergy underpinned by an off-target dependency. Further dissection of the intricate genetic dependencies that underlie synergy can pave the way to developing more effective combination strategies in gastric cancer therapy.

Impact of CD151 overexpression on prognosis and therapy in non-small cell lung cancer patients lacking EGFR mutations.

This study investigates CD151, a protein linked to cancer progression, in non-small cell lung cancer (NSCLC) patients without epidermal growth factor receptor (EGFR) mutations. These patients often have limited treatment options. The study used retrospective analysis to examine 157 adenocarcinoma biopsy specimens and 199 patient cases from The Cancer Genome Atlas, correlating CD151 expression with patient survival. Cellular studies revealed that CD151 interacts with EGFR, influencing epidermal growth factor (EGF)-induced cell proliferation and the effectiveness of the EGFR inhibitor, erlotinib. A strong association was found between CD151 expression and EGFR mutation status. High CD151 expression in the absence of EGFR mutations is correlated with poorer survival outcomes. Biological assays showed that CD151 colocalizes and associates with EGFR, playing a crucial role in regulating EGF-induced cell proliferation via the AKT and ERK1/2 pathways. Importantly, CD151 expression was found to influence the anti-proliferative effects of the EGFR tyrosine kinase inhibitor, erlotinib. High CD151 expression, in the absence of EGFR mutations, was associated with poorer survival outcomes. It could serve as a potential prognostic marker and influence cellular responses to EGFR-targeted treatments. This study highlights CD151 as a potential novel target for therapeutic intervention in NSCLC, especially in populations lacking EGFR mutations.

Functionalized solid lipid nanoparticles combining docetaxel and erlotinib synergize the anticancer efficacy against triple-negative breast cancer.

The goal of the study was to fabricate folic acid functionalized docetaxel (DOC)/erlotinib (ERL)-loaded solid lipid nanoparticles (SLNs) to synergistically increase the anticancer activity against triple-negative breast cancer. DOC/ERL-SLNs were prepared by the high shear homogenization - ultrasound dispersion method (0.1 % w/v for DOC, and 0.3 %w/v for ERL) and optimized using Plackett Burman Design (PBD) followed by Box Behnken Design (BBD). The optimized SLNs demonstrated particle size < 200 nm, PDI < 0.35, and negative zeta potential with entrapment and loading efficiency of ∼80 and ∼4 %, respectively. The SLNs and folic acid functionalized SLNs (FA-SLNs) showed sustained release for both drugs, followed by Higuchi and Korsemeyer-Peppas drug release models, respectively. Further, the in vitro pH-stat lipolysis model demonstrated an approximately 3-fold increase in the bioaccessibility of drugs from SLNs compared to suspension. The TEM images revealed the spherical morphology of the SLNs. DOC/ERL loaded SLNs showed dose- and time-dependent cytotoxicity and exhibited a synergism at a molar ratio of 1:3 in TNBC with a combination index of 0.35 and 0.37, respectively. FA-DOC/ERL-SLNs showed enhanced anticancer activity as evidenced by MMP and ROS assay and further inhibited the colony-forming ability and the migration capacity of TNBC cells. Conclusively, the study has shown that SLNs are encouraging systems to improve the pharmaceutical attributes of poorly bioavailable drugs.

Novel 1,3,4-oxadiazole derivatives of naproxen targeting EGFR: Synthesis, molecular docking studies, and cytotoxic evaluation.

The close association between inflammation and cancer inspired the synthesis of a series of 1,3,4-oxadiazole derivatives (compounds H4-A-F) of 6-methoxynaphtalene. The chemical structures of the new compounds were validated utilizing Fourier-transform infrared, proton nuclear magnetic resonance, and carbon-13 nuclear magnetic resonance spectroscopic techniques and CHN analysis. Computer-aided drug design methods were used to predict the compounds biological target, ADMET properties, toxicity, and to evaluate the molecular similarities between the design compounds and erlotinib, a standard epidermal growth factor receptor (EGFR) inhibitor. The antiproliferative effects of the new compounds were evaluated by the 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay, cell cycle analysis, apoptosis detection by microscopy, quantitative reverse transcription-polymerase chain reaction, and immunoblotting, and EGFR enzyme inhibition assay. In silico analysis of the new oxadiazole derivatives indicated that these compounds target EGFR, and that compounds H4-A, H4-B, H4-C, and H4-E show similar molecular properties to erlotinib. Additionally, the results indicated that none of the synthesized compounds are carcinogenic, and that compounds H4-A, H4-C, and H4-F are nontoxic. Compound H4-A showed the best-fit score against EGFR pharmacophore model, however, the in vitro studies indicated that compound H4-C was the most cytotoxic. Compound H4-C caused cytotoxicity in HCT-116 colorectal cancer cells by inducing both apoptosis and necrosis. Furthermore, compounds H4-D, H4-C, and H4-B had potent inhibitory effect on EGFR tyrosine kinase that was comparable to erlotinib. The findings of this inquiry offer a basis for further investigation into the differences between the synthesized compounds and erlotinib. However, additional testing will be needed to assess all of these differences and to identify the most promising compound for further research.

Preincubation-dependent inhibition of organic anion transporting polypeptide 2B1.

Preincubation with inhibitor in organic anion transporting polypeptide (OATP) in vitro assays may increase the inhibition potency of inhibitors compared to conventional inhibition assays with only short inhibitor coincubation with substrate. The decrease in IC50 may affect prediction of drug-drug interactions (DDI) involving these transporters and inhibitors. Only few drugs, however, have been assessed for the preincubation-dependent inhibition of the OATP2B1 transporter. Therefore, we studied the effect of preincubation on OATP2B1 inhibition with five known OATP2B1 inhibitors (atorvastatin, erlotinib, ezetimibe, ticagrelor and simeprevir) in HEK293 cells transiently overexpressing OATP2B1. IC50 values were determined with and without inhibitor preincubation for 20 min with three different OATP2B1 substrates (dibromofluorescein, DBF; 5-carboxyfluorescein, 5-CF; estrone sulfate). Atorvastatin, ezetimibe, and simeprevir displayed more than 2-fold lower IC50 values after preincubation with at least one of the tested substrates. Altogether, 4 out of 15 inhibitor/substrate combinations exhibited more than 2-fold potentiation of IC50 after inhibitor preincubation. In addition, preincubation by itself, without inhibitor present with the substrate, resulted in more than 50% inhibition of OATP2B1-mediated uptake of DBF and/or 5-CF by atorvastatin, ticagrelor and simeprevir. Thus, erlotinib was the only inhibitor with no indication of potentiation of inhibition by preincubation with any of the tested substrates. In conclusion, preincubation resulted in inhibitor- and substrate-dependent inhibition of OATP2B1. These results support the conclusion that to reduce the risk of false negative DDI prediction, preincubation should be considered also in OATP2B1 inhibition assays.

Influence of Tyrosine Kinase Inhibitors and Everolimus on TGFß1 and TGF-ß Receptor 2 in Squamous Cell Carcinoma Cells.

BACKGROUND/AIM: Transforming growth factor-ß (TGF-ß) plays a significant role in the formation of different cancer subtypes. There is evidence that TGF-ß pathways promote cancerogenic cell characteristics but also have tumor-suppressor capabilities. The tyrosine kinase inhibitors nilotinib, dasatinib, erlotinib, gefitinib, and everolimus are approved as targeted therapies for several tumor entities, including head and neck squamous cell carcinoma (HNSCC). This study aimed to investigate the effects of these substances on the expression levels of TGFß1 and TGF-ß receptor type 2 (TGFßR2) in HPV-negative and HPV-positive SCC cell cultures. MATERIALS AND METHODS: Expression patterns of TGFß1 and TGFßR2 were determined using enzyme-linked immunosorbent assay (ELISA) in three HNSCC cell lines (i.e., HNSCC-11A, HNSCC-14C, and CERV196). These cells were incubated with nilotinib, dasatinib, erlotinib, gefitinib, and everolimus (20 µmol/l) and compared to a chemonaive control. An assessment of concentration levels was conducted after 24, 48, 72, and 96 h of treatment. RESULTS: Statistically significant changes in the expression levels of TGFß1 and TGFßR2 were found in all tested cell cultures (p<0.05) compared to the negative control. An increase in TGFß-R2 expression was detected after treatment with most of the tested tyrosine kinase inhibitors, whereas a reduction in TGFß1 was observed. The addition of everolimus had the opposite effect on both TGFßR2 and TGF-B1- expression. CONCLUSION: Expression of TGFß1 and TGFßR2 was detected in all cultured HNSCC cell lines. Nilotinib, dasatinib, erlotinib, gefitinib, and everolimus had an impact on the expression levels of TGFß1 and TGFßR2 in vitro.

The Drug-Drug Interaction between Erlotinib and OSI-930 Is Mediated through Aldehyde Oxidase Inhibition.

The propensity for aldehyde oxidase (AO) substrates to be implicated in drug-drug interactions (DDIs) is not well understood due to the dearth of potent inhibitors that elicit in vivo inhibition of AO. Although there is only one reported instance of DDI that has been ascribed to the inhibition of AO to date, the supporting evidence for this clinical interaction is rather tenuous, and its veracity has been called into question. Our group recently reported that the epidermal growth factor receptor inhibitor erlotinib engendered potent time-dependent inhibition of AO with inactivation kinetic constants in the same order of magnitude as its free circulating plasma concentrations. At the same time, it was previously reported that the concomitant administration of erlotinib with the investigational drug OSI-930 culminated in a an approximately twofold increase in its systemic exposure. Although the basis underpinning this interaction remains unclear, the structure of OSI-930 contains a quinoline motif that is amenable to oxidation at the electrophilic carbon adjacent to the nitrogen atom by molybdenum-containing hydroxylases like AO. In this study, we conducted metabolite identification that revealed that OSI-930 undergoes AO metabolism to a mono-oxygenated 2-oxo metabolite and assessed its formation kinetics in human liver cytosol. Additionally, reaction phenotyping in human hepatocytes revealed that AO contributes nearly 50% to the overall metabolism of OSI-930. Finally, modeling the interaction between erlotinib and OSI-930 using a mechanistic static model projected an ∼1.85-fold increase in the systemic exposure of OSI-930, which accurately recapitulated clinical observations. SIGNIFICANCE STATEMENT: This study delineates an aldehyde oxidase (AO) metabolic pathway in the investigational drug OSI-930 for the first time and confirmed that it represented a major route of metabolism through reaction phenotyping in human hepatocytes. Our study provided compelling mechanistic and modeling evidence for the first instance of an AO-mediated clinical drug-drug interaction stemming from the in vivo inhibition of the AO-mediated quinoline 2-oxidation pathway in OSI-930 by erlotinib.

Epidermal growth factor receptor/mitogen-activated kinase inhibitor treatment induces a distinct inflammatory hair follicle response that includes collapse of immune privilege.

BACKGROUND: Inhibitors of epidermal growth factor receptor (EGFRi) or mitogen-activated kinase (MEKi) induce a folliculitis in 75-90% of patients, the pathobiology of which remains insufficiently understood. OBJECTIVES: To characterize changes in the skin immune status and global transcriptional profile of patients treated with EGFRi; to investigate whether EGFRi affects the hair follicle's (HF) immune privilege (IP); and to identify early proinflammatory signals induced by EGFRi/MEKi in human scalp HFs ex vivo. METHODS: Scalp biopsies were taken from patients exhibiting folliculitis treated long term with EGFRi ('chronic EGFRi' group, n = 9) vs. healthy scalp skin (n = 9) and patients prior to commencing EGFRi treatment and after 2 weeks of EGFRi therapy ('acute EGFRi' group, n = 5). Healthy organ-cultured scalp HFs were exposed to an EGFRi (erlotinib, n = 5) or a MEKi (cobimetinib, n = 5). Samples were assessed by quantitative immunohistomorphometry, RNA sequencing (RNAseq) and in situ hybridization. RESULTS: The 'chronic EGFRi' group showed CD8+ T-cell infiltration of the bulge alongside a partial collapse of the HF's IP, evidenced by upregulated major histocompatibility complex (MHC) class I, ß2-microglobulin (B2 M) and MHC class II, and decreased transforming growth factor-ß1 protein expression. Healthy HFs treated with EGFRi/MEKi ex vivo also showed partial HF IP collapse and increased transcription of human leucocyte antigen (HLA)-A, HLA-DR and B2 M transcripts. RNAseq analysis showed increased transcription of chemokines (CXCL1, CXCL13, CCL18, CCL3, CCL7) and interleukin (IL)-26 in biopsies from the 'chronic EGFRi' cohort, as well as increased IL-33 and decreased IL-37 expression in HF biopsies from the 'acute EGFRi' group and in organ-cultured HFs. CONCLUSIONS: The data show that EGFRi/MEKi compromise the physiological IP of human scalp HFs and suggest that future clinical management of EGFRi/MEKi-induced folliculitis requires HF IP protection and inhibition of IL-33.

About 75­90% of people with cancer who are treated with drugs called EGFR inhibitors (EGFRi) and MEK inhibitors (MEKi) will get a skin condition called folliculitis. This is where the hair follicles become inflamed. Despite this, the reasons why some patients develop this are not well understood. In this study, we had three goals. We wanted to understand how these medications alter the skin's immune response and genetic processes. We also wished to determine the impact of the medications on the immune protection of hair follicles. Finally, we wanted to find early signs of inflammation in hair follicles caused by the medications. We studied scalp samples from people who got folliculitis after long-term EGFRi treatment and compared them to samples of healthy scalp skin. We also examined patients before and after they began EGFRi treatment. In the lab, we exposed healthy hair follicles to an EGFRi called 'erlotinib' or a MEKi called 'cobimetinib'. We then carried out detailed imaging and genetic analyses. We found that long-term treatment with EGFRi increased certain immune cells (called CD8+ T cells) in the hair follicle area. This led to a breakdown in the immune protection around hair follicles. A similar breakdown was found in lab-treated healthy follicles. Genetic changes linked to inflammation were also found. Our findings suggest that EGFRi and MEKi treatments could affect the natural immune defence of hair follicles in the scalp and cause folliculitis. Protecting the immune system and controlling inflammation might be the key to treating people with these drug-related skin conditions.

Development of a Supermolecular Radionuclide-Drug Conjugate System for Integrated Radiotheranostics for Non-small Cell Lung Cancer.

Radionuclide-drug conjugates (RDCs) designed from small molecule or nanoplatform shows complementary characteristics. We constructed a new RDC system with integrated merits of small molecule and nanoplatform-based RDCs. Erlotinib was labeled with 131I to construct the bulk of RDC (131I-ER). Floxuridine was mixed with 131I-ER to develop a hydrogen bond-driving supermolecular RDC system (131I-ER-Fu NPs). The carrier-free 131I-ER-Fu NPs supermolecule not only demonstrated integrated merits of small molecule and nanoplatform-based RDC, including clear structure definition, stable quality control, prolonged circulation lifetime, enhanced tumor specificity and retention, and rapidly nontarget clearance, but also exhibited low biological toxicity and stronger antitumor effects. In vivo imaging also revealed its application for tumor localization of nonsmall cell lung cancer (NSCLC) and screening of patients suitable for epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) therapy. We considered that 131I-ER-Fu NPs showed potentials as an integrated platform for the radiotheranostics of NSCLC.

A Novel Boron Dipyrromethene-Erlotinib Conjugate for Precise Photodynamic Therapy against Liver Cancer.

Photodynamic Therapy (PDT) is recognized for its exceptional effectiveness as a promising cancer treatment method. However, it is noted that overexposure to the dosage and sunlight in traditional PDT can result in damage to healthy tissues, due to the low tumor selectivity of currently available photosensitizers (PSs). To address this challenge, we introduce herein a new strategy where the small molecule-targeted agent, erlotinib, is integrated into a boron dipyrromethene (BODIPY)-based PS to form conjugate 6 to enhance the precision of PDT. This conjugate demonstrates optical absorption, fluorescence emission, and singlet oxygen generation efficiency comparable to the reference compound 7, which lacks erlotinib. In vitro studies reveal that, after internalization, conjugate 6 predominantly accumulates in the lysosomes of HepG2 cells, exhibiting significant photocytotoxicity with an IC50 value of 3.01 µM. A distinct preference for HepG2 cells over HELF cells is observed with conjugate 6 but not with compound 7. In vivo experiments further confirm that conjugate 6 has a specific affinity for tumor tissues, and the combination treatment of conjugate 6 with laser illumination can effectively eradicate H22 tumors in mice with outstanding biosafety. This study presents a novel and potential PS for achieving precise PDT against cancer.

RP11-874 J12.4 promotes erlotinib resistance in non-small cell lung cancer via increasing AXL expression.

EGFR tyrosine kinase inhibitor (TKI) resistance is a major challenge for EGFR-mutant non-small cell lung cancer (NSCLC) treatment. Our previous work revealed that overexpression of AXL promoted EGFR-TKI resistance through epithelial-mesenchymal transition (EMT) in a subset of NSCLC patients. Compared with erlotinib resistant and sensitive cells, RP11-874 J12.4 was upregulated in erlotinib-resistant NSCLC cells (HCC827-ER3). Interestingly, the expression of RP11-874 J12.4 positively correlated with AXL. Besides, RP11-874 J12.4 promotes NSCLC cell proliferation and metastasis in vitro. Mechanistically, RP11-874 J12.4 promoted AXL expression through sponge with miR-34a-5p, which was reported to inhibit the translation of AXL mRNA. Meanwhile, the expression of RP11-874 J12.4 in lung cancer tumors were higher than the adjacent tissue, and those patients with high expression of RP11-874 J12.4 showed a poor prognosis in clinical. High expression of RP11-874 J12.4 might be a biomarker for NSCLC patients with erlotinib resistance. These findings reveal a novel insight into the mechanism of erlotinib resistance in NSCLC, and it might be a promising target for the diagnosis and treatment of NSCLC.

EGFR inhibits TNF-α-mediated pathway by phosphorylating TNFR1 at tyrosine 360 and 401.

Tumour necrosis factor receptor 1 (TNFR1) induces the nuclear factor kappa-B (NF-κB) signalling pathway and regulated cell death processes when TNF-α ligates with it. Although mechanisms regulating the downstream pathways of TNFR1 have been elucidated, the direct regulation of TNFR1 itself is not well known. In this study, we showed that the kinase domain of the epidermal growth factor receptor (EGFR) regulates NF-κB signalling and TNF-α-induced cell death by directly phosphorylating TNFR1 at Tyr 360 and 401 in its death domain. In contrast, EGFR inhibition by EGFR inhibitors, such as erlotinib and gefitinib, prevented their interaction. Once TNFR1 is phosphorylated, its death domain induces the suppression of the NF-κB pathways, complex II-mediated apoptosis, or necrosome-dependent necroptosis. Physiologically, in mouse models, EGF treatment mitigates TNF-α-dependent necroptotic skin inflammation induced by treatment with IAP and caspase inhibitors. Our study revealed a novel role for EGFR in directly regulating TNF-α-related pathways.