DNA-Mediated Magnetic-Dimer Assembly for Fault-Free Ultra-High-Field Magnetic Resonance Imaging of Tumors.

Ultra-high-field (UHF) magnetic resonance imaging (MRI) stands as a pivotal cornerstone in biomedical imaging, yet the challenge of false imaging persists, constraining its full potential. Despite the development of dual-mode contrast agents improving conventional MRI, their effectiveness in UHF remains suboptimal due to the high magnetic moment, resulting in diminished T1 relaxivity and excessively enhanced T2 relaxivity. Herein, we report a DNA-mediated magnetic-dimer assembly (DMA) of iron oxide nanoparticles that harnesses UHF-tailored nanomagnetism for fault-free UHF-MRI. DMA exhibits a dually enhanced longitudinal relaxivity of 4.42 mM-1·s-1 and transverse relaxivity of 26.23 mM-1·s-1 at 9 T, demonstrating a typical T1-T2 dual-mode UHF-MRI contrast agent. Importantly, DMA leverages T1-T2 dual-modality image fusion to achieve artifact-free breast cancer visualization, effectively filtering interference from hundred-micrometer-level false-positive signals with unprecedented precision. The UHF-tailored T1-T2 dual-mode DMA contrast agents hold promise for elevating the accuracy of MR imaging in disease diagnosis.

Ligand-Mediated Magnetism-Conversion Nanoprobes for Activatable Ultra-High Field Magnetic Resonance Imaging.

Ultra-high field (UHF) magnetic resonance imaging (MRI) has emerged as a focal point of interest in the field of cancer diagnosis. Despite the ability of current paramagnetic or superparamagnetic smart MRI contrast agents to selectively enhance tumor signals in low-field MRI, their effectiveness at UHF remains inadequate due to inherent magnetism. Here, we report a ligand-mediated magnetism-conversion nanoprobe (MCNP) composed of 3-mercaptopropionic acid ligand-coated silver-gadolinium bimetallic nanoparticles. The MCNP exhibits a pH-dependent magnetism conversion from ferromagnetism to diamagnetism, facilitating tunable nanomagnetism for pH-activatable UHF MRI. Under neutral pH, the thiolate (-S- ) ligands lead to short τ'm and increased magnetization of the MCNPs. Conversely, in the acidic tumor microenvironment, the thiolate ligands are protonated and transform into thiol (-SH) ligands, resulting in prolonged τ'm and decreased magnetization of the MCNP, thereby enhancing longitudinal relaxivity (r1) values at UHF MRI. Notably, under a 9 T MRI field, the pH-sensitive changes in Ag-S binding affinity of the MCNP lead to a remarkable (>10-fold) r1 increase in an acidic medium (pH 5.0). In vivo studies demonstrate the capability of MCNPs to amplify MRI signal of hepatic tumors, suggesting their potential as a next-generation UHF-tailored smart MRI contrast agent.

All-fiber high-power spatiotemporal mode-locked laser based on multimode interference filtering.

Multimode interference (MMI) has been considered to be critical and investigated extensively in mode-locked laser based on single transverse mode systems, whereas there are few researches related to three-dimensional nonlinear dynamics within lasers. In this paper, we demonstrate all-fiber high-power spatiotemporal mode-locked (STML) laser by optimizing MMI filtering, where we find that the MMI filtering plays an important role in counteracting the coupling of high-order modes and improving output power of STML laser. The results under weak coupling condition when the length of graded-index multimode fiber (GIMF) is integral multiple of beat length show that the oscillator generates dissipative soliton pulses at 1036.86 nm with pulse width of 5.65 ps, and the slope efficiency of pump-signal is up to 10.3% with average power/energy of 215 mW/6 nJ, which is the highest among all-fiber STML lasers in normal dispersion regime. Besides, the multiple-soliton of STML, including multiple pulses and harmonic mode-locking can be observed in the experiment. Our work significantly broadens the dimensions of design for all-fiber high-power STML and makes them much more accessible for being put into applications.

All-fiber dual-wavelength mode-locked fiber laser based on microfiber-assisted NL-MMI.

We present what we believe is a novel approach to generate a dual wavelength in a single fiber-ring oscillator, which is based on microfiber-assisted nonlinear multimode interference. In the software simulation, the mode locker could not only strengthen the spatial filtering and spectral filtering but could also improve the signal-to-noise ratio of the mode-locked pulse over the single mode fiber-graded index multimode fiber-single mode fibers (SMSs). In the experiment, the stable and compact dual-wavelength mode-locked output was achieved by using the proposed mode-locked fiber laser, without any complex controlling electronics. This new optimized mode-locking method provides a compact and low-cost solution for dual-comb systems.

Tunable mode-locked fiber laser based on nonlinear multimode interference with double offset-splicing step-index few-mode fiber.

A tunable mode-locked all-fiber Yb-doped laser with a double offset-splicing step-index few-mode fiber (DOS-SIFMF) is demonstrated, to the best of our knowledge, for the first time. The structure of DOS-SIFMF, which constructs a micro Mach-Zehnder interferometer as a consequence of introducing offset splicing, has characteristics of both a saturable absorber and filter and is more accessible to obtain mode-locking operation in an all-normal dispersive region. The results of simulation show that interference with fewer modes is more reliable to acquire mode-locking operation of the fiber laser. The central wavelength, spectrum, and pulse widths are 1032 nm, 6.15 nm, and 28.8 ps, respectively. The output pulse in time and spectrum domains can be tuned in the range of 168.7 ps and 10.7 nm, respectively. This structure has effects of both mode-locking and filtering, showing potential application in communication and sensing. Furthermore, the influence on mode number to interference is generally discussed in the end.

LncRNA LIMT (LINC01089) contributes to sorafenib chemoresistance via regulation of miR-665 and epithelial to mesenchymal transition in hepatocellular carcinoma cells.

Hepatocellular carcinoma (HCC) is one of the most malignant tumors worldwide and HCC patients often develop drug resisitene. Long non-coding RNAs (LncRNAs) are closely related to cell cycle, growth, development, differentiation, and apoptosis. Abnormally expressed lncRNAs have been proved to mediate drug resistance in tumor cells. However, the effect of LIMT on drug resistance has not been explored in HCC. In this study, we explored the effect of long non-coding RNA LIMT on drug resistance and its underlying mechanism in hepatocellular carcinoma (HCC). Our results showed that LncRNA LINC01089 (LIMT) expression is downregulated in 78.57% (44/56) of 56 HCC tumor tissue samples. LIMT expression is also downregulated in HCC cells compared with that in normal liver LO2 cells. Inhibition of LIMT increases the resistance to sorafenib and promotes cell invasion via regulation of epithelial to mesenchymal transition (EMT) in HCC. StarBase V3.0 was used to predict the potential binding site of miR-665 in . Furthermore, miR-665 participates in sorafenib resistance and also regulates the level of EMT-related proteins in HCC cells. A rescue experiment demonstrated that silencing of eliminats the inhibitory effect of the miR-665 inhibitor on sorafenib resistance in HCC cells. Taken together, our findings revealed that downregulation of LIMT increases the resistance of HCC to sorafenib via miR-665 and EMT. Therefore, LIMT, which serves as a therapeutically effective target, will provide new hope for the treatment of HCC.

Study of the Cycloaddition of CO2 with Styrene Oxide Over Six-Connected spn Topology MOFs (Zr, Hf) at Room Temperature.

A series of MOFs with a 6-connected spn topology were synthesized (MOF-808-(Zr, Hf), PCN-777-(Zr, Hf), MOF-818-(Zr, Hf)). Through the in situ DRIFTS of NH3 adsorption-desorption, we found that the activated catalyst mainly contains Lewis acid sites. The effects of different organic ligands on the Lewis acid of the Zr6 cluster were analyzed by XPS and NH3 -TPD, and the relative Lewis acidity of the same metal was obtained: PCN-777>MOF-808>MOF-818. In the Py-FTIR results, we confirmed that MOF-818 has a higher acid site density. In the activity test, MOFs with mesoporous structure showed better catalytic activity under normal temperature and pressure. Among them, MOF-818 can still maintain a high degree of crystallinity after catalysis. Finally, we use density functional theory to propose the mechanism of the cycloaddition reaction of carbon dioxide and styrene oxide. The results show that the metal is coordinated with styrene oxide and halogens attack the ß carbon of the epoxide.

MiR-223 regulates autophagy associated with cisplatin resistance by targeting FBXW7 in human non-small cell lung cancer.

BACKGROUND: Cisplatin is widely used as a first-line treatment for non-small cell lung cancer (NSCLC), but chemoresistance remains a major clinical obstacle for efficient use. As a microRNA, miR-223 was reported to promote the doxorubicin resistance of NSCLC. However, whether miR-223 is also involved in cisplatin resistance of NSCLC and the mechanism miR-223 involved in drug resistance is unclear. Accumulated evidence has shown that abnormal autophagy is associated with tumor chemoresistance. The study aimed to study the role of miR-223 on cisplatin sensitivity in NSCLC and uncover the potential mechanisms. METHODS: NSCLC cells transfected with mimic or inhibitor for miR-223 was assayed for chemoresistance in vitro. MiR-223 expression was assessed by quantitative real-time PCR (qRT-PCR). Western blot were used to study the expression level of F-box/WD repeat-containing protein 7 (FBXW7) and autophagy-related protein. The effect of miR-223 on cisplatin sensitivity was examined by using CCK-8, EdU assays and Autophagic flux assay. Luciferase assays, EdU assays and small interfering RNA were performed to identify the targets of miR-223 and the mechanism by which it promotes treatment resistance. Xenograft models were established to investigate the effect of mir-223 on cisplatin sensitivity. RESULTS: In the present study, we found that the level of miR-223 was significantly positively correlated with cisplatin resistance. MiR-223 overexpression made NSCLC cells resistant to cisplatin treatment. We further found that autophagy mediated miR-223-mediated cisplatin resistance in NSCLC cells. Further mechanistic research demonstrated that miR-223 directly targeted FBXW7. The overexpression of miR-223 could inhibit the level of FBXW7 protein expression, thus promoting autophagy and making NSCLC cells resistant to cisplatin. Finally, we confirmed the increased effect of cisplatin sensitivity by miR-223 Antagomir in xenograft models of NSCLC. CONCLUSIONS: Our results demonstrate that miR-223 could enhance autophagy by targeting FBXW7 in NSCLC cells. Inhibition of autophagy by miR-223 knockdown provides a novel treatment strategy to alleviate cisplatin resistance in NSCLC.

Inhibition of LncRNA MALAT1 Attenuates Cerebral Ischemic Reperfusion Injury via Regulating AQP4 Expression.

Stroke is one of the leading causes of mortality and disability worldwide. Long noncoding RNAs (lncRNAs) including MALAT1 have been shown to have critical roles in cerebral ischemia reperfusion injury (CIRI). However, the underlying mechanism of MALAT1 in CIRI has not been elucidated. The present study aimed to investigate the function and potential regulatory mechanism of MALAT1 in cerebral ischemic reperfusion injury. We established the middle cerebral artery occlusion (MCAO) model and oxygen-glucose deprivation/reoxygenation (OGD/RX) model in vivo and in vitro, and then Cell Counting Kit-8 (CCK-8), RT-qPCR, flow cytometry analysis, lactate dehydrogenase (LDH) analysis, and 2,3,5-triphenyltetrazolium chloride (TTC) staining were used to examine cell viability, MALAT1, aquaporin-4 (AQP4) expression, LDH release, and infarct volume, respectively. The level of AQP4 was remarkably upregulated in CIRI 24 h/48 h or OGD/RX 24 h/48 h compared with the sham group. Knockdown of AQP4 could alleviate OGD/RX-induced injury through enhancing cell viability and reducing LDH release and the rate of apoptotic cells. Furthermore, we found that MALAT1 was also increased in OGD/RX 24 h/48 h and silencing of MALAT1 could decrease AQP4. Inhibition of MALAT1 could also protect OGD/RX-induced injury, while the protective effect of MALAT1 siRNA on cerebral ischemic reperfusion was disappeared after transfection with AQP4 plasmid, indicating that MALAT1 may play a protective role in brain stroke through regulating AQP4. Taken together, our study provides evidence that MALAT1 is involved in ischemic stroke by inhibiting AQP4. Therefore, MALAT1 may serve as a potential target for therapeutic intervention in ischemic brain injury.

MicroRNA-212 suppresses nonsmall lung cancer invasion and migration by regulating ubiquitin-specific protease-9.

MicroRNAs (miRNAs) play crucial roles in various biological processes, including migration, proliferation, differentiation, cell cycling, and apoptosis. Epithelial-mesenchymal transition (EMT) has been shown to be related to the capability of migration and invasion in many tumor cells. In this study, we used wound-healing assay and transwell invasion to analysis the capability of migration and invasion in non-small-cell lung carcinoma (NSCLC), respectively. The expression of ubiquitin-specific protease-9-X-linked (USP9X) and miR-212 messenger RNA (mRNA) was determined by quantitative real-time polymerase chain reaction and Western blot analysis was used to determine the E-cadherin and vimentin expression. Our results showed that miR-212 mimic inhibited cell migration and invasion, while miR-212 inhibitor increased cell migration and invasion. There was no significant difference between WP1130 and miR-212 mimic combined with WP1130 groups. Moreover, WP1130 inhibited the capability of the migration and invasion of NSCLC cells. Western blot analysis displayed that miR-212 mimic upregulated E-cadherin expression and downregulated vimentin expression, while miR-212 inhibitor downregulated E-cadherin and upregulated vimentin expression. These data showed that miR-212 regulated NSCLC cell invasion and migration by regulating USP9X expression. Taken together, these findings indicated that miR-212 regulated NSCLC cells migration and invasion through targeting USP9X involved in EMT.

Hook1 inhibits malignancy and epithelial-mesenchymal transition in hepatocellular carcinoma.

Hook1 is a member of the hook family of coiled-coil proteins, which is recently found to be associated with malignant tumors. However, its biological function in hepatocellular carcinoma is yet unknown. Here, we evaluated the Hook1 levels in human hepatocellular carcinoma samples and matched peritumoral tissues by real-time polymerase chain reaction. Small interfering RNA knockdown and a transforming growth factor-ß-induced epithelial-mesenchymal transition model were employed to investigate the biological effects of Hook1 in hepatocellular carcinoma. Our results indicated that Hook1 levels were significantly lower in hepatocellular carcinoma tissues than in the peritumoral tissues. In addition, Hook1 expression was significantly associated with hepatocellular carcinoma malignancy. Hook1 was downregulated after transforming growth factor-ß-induced epithelial-mesenchymal transition. Moreover, Hook1 knockdown promoted epithelial-mesenchymal transition and attenuated the sensitivity of hepatocellular carcinoma cells to doxorubicin. In summary, our results indicate that downregulation of Hook1 plays a pivotal role in hepatocellular carcinoma progression via epithelial-mesenchymal transition. Hook1 may be used as a novel marker and therapeutic molecular target in hepatocellular carcinoma.

Calcein-acetoxymethy ester enhances the antitumor effects of doxorubicin in nonsmall cell lung cancer by regulating the TopBP1/p53RR pathway.

Calcein acetoxymethyl ester (calcein-AM) treatment has been reported to exert antitumor effects in certain cancer cells; however, the detailed mechanism of action of calcein-AM in cancers remains unclear, especially in nonsmall cell lung cancer (NSCLC). This study focused on the function and mechanism of action of calcein-AM in NSCLC. We used cell viability assays, western blotting, and EdU proliferation assay combined with calcein-AM treatment or siRNA interference to investigate the role of topoisomerase IIß binding protein 1 (TopBP1) and p53 in NSCLC chemotherapy. We found that calcein-AM has antitumor effects in lung cancer and enhances the antitumor effects of doxorubicin in NSCLC. Furthermore, we found that TopBP1, which we previously showed was involved in doxorubicin resistance through upregulation of aberrant p53, was involved in calcein-AM-mediated increased doxorubicin sensitivity. Doxorubicin upregulated the expression of aberrant p53. Calcein-AM repressed the expression of TopBP1, which resulted in reduced expression of aberrant p53 and disrupted the antiapoptotic activity mediated by the TopBP1/mutp53 pathway in NSCLC. Together, our findings show that calcein-AM, the cell-permeable derivative of calcein, exerts significant antitumor effects in NSCLC, and can enhance the antitumor effect of doxorubicin by regulating the TopBP1/mutp53 pathway. These findings provide novel insight into lung cancer treatment.

An Immunomodulatory Zinc-Alum/Ovalbumin Nanovaccine Boosts Cancer Metalloimmunotherapy Through Erythrocyte-Assisted Cascade Immune Activation.

Cancer therapeutic vaccines are powerful tools for immune system activation and eliciting protective responses against tumors. However, their efficacy has often been hindered by weak and slow immune responses. Here, the authors introduce an immunization strategy employing senescent erythrocytes to facilitate the accumulation of immunomodulatory zinc-Alum/ovalbumin (ZAlum/OVA) nanovaccines within both the spleen and solid tumors by temporarily saturating liver macrophages. This approach sets the stage for boosted cancer metalloimmunotherapy through a cascade immune activation. The accumulation of ZAlum/OVA nanovaccines in the spleen substantially enhances autophagy-dependent antigen presentation in dendritic cells, rapidly initiating OVA-specific T-cell responses against solid tumors. Concurrently, ZAlum/OVA nanovaccines accumulated in the tumor microenvironment trigger immunogenic cell death, leading to the induction of individualized tumor-associated antigen-specific T cell responses and increased T cell infiltration. This erythrocyte-assisted cascade immune activation using ZAlum/OVA nanovaccines results in rapid and robust antitumor immunity induction, holding great potential for clinical cancer metalloimmunotherapy.

Alpha-Synuclein Oligomers Driven T1-T2 Switchable Nanoprobes for Early and Accurate Diagnosis of Parkinson's Disease.

The alpha-synuclein (α-syn) oligomers hold a central role in the pathology of Parkinson's disease (PD). Achieving accurate detection of α-syn oligomers in vivo presents a promising avenue for early and accurate diagnosis of PD. Magnetic resonance imaging (MRI), with non-invasion and exceptional tissue penetration, offers a potent tool for visualizing α-syn oligomers in vivo. Nonetheless, ensuring diagnostic specificity remains a formidable challenge. Herein, a novel MRI probe (ASOSN) is introduced, which encompasses highly sensitive antiferromagnetic nanoparticles functionalized with single-chain fragment variable antibodies, endowing it with the capacity for discerning recognition and binding to α-syn oligomers and triggering a switchable T1-T2 MRI signal. Significantly, ASOSN possesses the unique capability to accurately discriminate α-syn oligomers from neuroinflammation in vivo. Moreover, ASOSN facilitates the non-invasive and precise visualizing of endogenous α-syn oligomers in living systems. This innovative design heralds the development of a non-invasive visualization strategy for α-syn oligomers, marking a pivotal advancement for early and accurate diagnosis of PD.

Ligand-Induced Atomically Segregation-Tunable Alloy Nanoprobes for Enhanced Magnetic Resonance Imaging.

Bimetallic iron-noble metal alloy nanoparticles have emerged as promising contrast agents for magnetic resonance imaging (MRI) due to their biocompatibility and facile control over the element distribution. However, the inherent surface energy discrepancy between iron and noble metal often leads to Fe atom segregation within the nanoparticle, resulting in limited iron-water molecule interactions and, consequently, diminished relaxometric performance. In this study, we present the development of a class of ligand-induced atomically segregation-tunable alloy nanoprobes (STAN) composed of bimetallic iron-gold nanoparticles. By manipulating the oxidation state of Fe on the particle surface through varying molar ratios of oleic acid and oleylamine ligands, we successfully achieve surface Fe enrichment. Under the application of a 9 T MRI system, the optimized STAN formulation, characterized by a surface Fe content of 60.1 at %, exhibits an impressive r1 value of 2.28 mM-1·s-1, along with a low r2/r1 ratio of 6.2. This exceptional performance allows for the clear visualization of hepatic tumors as small as 0.7 mm in diameter in vivo, highlighting the immense potential of STAN as a next-generation contrast agent for highly sensitive MR imaging.

Wnt/ß-catenin signaling enhances hypoxia-induced epithelial-mesenchymal transition in hepatocellular carcinoma via crosstalk with hif-1α signaling.

Epithelial-mesenchymal transition (EMT) is a critical process for tumor invasion and metastasis. Hypoxia may induce EMT, and upregulated ß-catenin expression has been found in various tumors. In this study, we investigate the role of ß-catenin in hypoxia-induced EMT in hepatocellular carcinoma (HCC). Induction of EMT in HCC cell lines by hypoxia was confirmed by altered morphology, expression change of EMT-associated markers and enhanced invasion capacity. We showed that hypoxia-induced EMT could be enhanced by addition of recombinant Wnt3a while it was repressed by ß-catenin small interfering RNA. An interaction between ß-catenin and hypoxia-induced factor-1α (hif-1α) was found, and an underlying competition for ß-catenin between hif-1α and T-cell factor-4 was implied. Notably, increased hif-1α activity was accompanied with more significant EMT features. We also showed that the pro-EMT effect of ß-catenin in hypoxia was deprived in the absence of hif-1α. Moreover, ß-catenin was found to be responsible for the maintenance of viability and proliferation for tumor cells undergoing hypoxia. We further showed a correlation between hif-1α and ß-catenin expression, and corresponding expression of EMT-associated markers in human HCC tissues. Our results suggest that Wnt/ß-catenin signaling enhances hypoxia-induced EMT in HCC by increasing the EMT-associated activity of hif-1α and preventing tumor cell death.

A Cancer Cell Selective Replication Stress Nano Amplifier Promotes Replication Fork Catastrophe to Overcome Radioresistance.

Replication stress (RS) induced by DNA damage plays a significant role in conferring the anticancer effects of radiotherapy and is tightly associated with radioresistance of cancer cells. Amplification of RS represents an effective approach to improving the efficacy of radiotherapy, although the development of selective RS amplifiers remains an unexplored frontier. We herein present an RS nano amplifier (RSNA) consisting of a catalytic FePt nanoparticle loaded with the chemotherapeutic doxorubicin (DOX), which selectively exacerbates RS in cancer cells by promoting replication fork (RF) catastrophe. RSNA converts the excessive reactive oxygen species (ROS) in cancer cells into oxygen, enhancing the DNA-damaging effects of radiotherapy to create more template lesions that impede RF progression in coalition with DOX. After radiation, ROS scavenging by RSNA accelerates RF progression through damaged template strands, increasing the frequency of RF collapse into double-strand breaks. Moreover, pretreatment with RSNA accumulates cancer cells in the S phase, exposing more RFs to radiation-induced RS. These effects of RSNA convergently maximize RS in cancer cells, effectively overcoming the radioresistance of cancer cells without affecting normal cells. Our study demonstrates the feasibility of selectively amplifying RS to boost radiotherapy.

A Peritumorally Injected Immunomodulating Adjuvant Elicits Robust and Safe Metalloimmunotherapy against Solid Tumors.

Clinical immunotherapy of solid tumors elicits durable responses only in a minority of patients, largely due to the highly immunosuppressive tumor microenvironment (TME). Although rational combinations of vaccine adjuvants with inflammatory cytokines or immune agonists that relieve immunosuppression represent an appealing therapeutic strategy against solid tumors, there are unavoidable nonspecific toxicities due to the pleiotropy of cytokines and undesired activation of off-target cells. Herein, a Zn2+ doped layered double hydroxide (Zn-LDH) based immunomodulating adjuvant, which not only relieves immunosuppression but also elicits robust antitumor immunity, is reported. Peritumorally injected Zn-LDH sustainably neutralizes acidic TME and releases abundant Zn2+ , promoting a pro-inflammatory network composed of M1-tumor-associated macrophages, cytotoxic T cells, and natural-killer cells. Moreover, the Zn-LDH internalized by tumor cells effectively disrupts endo-/lysosomes to block autophagy and induces mitochondrial damage, and the released Zn2+ activates the cGas-STING signaling pathway to induce immunogenic cell death, which further promotes the release of tumor-associated antigens to induce antigen-specific cytotoxic T lymphocytes. Unprecedentedly, merely injection of Zn-LDH adjuvant, without using any cytotoxic inflammatory cytokines or immune agonists, significantly inhibits the growth, recurrence, and metastasis of solid tumors in mice. This study provides a rational bottom-up design of potent adjuvant for cancer metalloimmunotherapy against solid tumors.

Gefitinib enhances the anti­tumor immune response against EGFR­mutated NSCLC by upregulating B7H5 expression and activating T cells via CD28H.

Gefitinib is a sensitive and effective drug to treat non­small­cell lung cancer (NSCLC) carrying the somatic activating mutations of the tyrosine kinase domain of epidermal growth factor receptor (EGFR). In the present study, a new mechanism of action of gefitinib in EGFR­mutated NSCLC cells was discovered using in vitro co­culture of NSCLC cells with peripheral blood mononuclear cells (PBMCs). Gefitinib significantly enhanced the cytotoxicity of PBMCs against NSCLC cells expressing mutated EGFR but not in cells expressing wild­type EGFR. Furthermore, it was observed that B7H5 expression was significantly lower in EGFR­mutant cells than in wild­type cells, while inhibition of EGFR by gefitinib or reduction in EGFR using a small interfering RNA (siRNA) both increased the expression of B7H5 in EGFR­mutated NSCLC cells. In addition, when B7H5 expression was reduced by siRNA, the toxic effect of gefitinib was reduced in the co­culture of PBMCs and EGFR­mutant NSCLC cells. In addition, the siRNA­mediated decrease in expression of the B7H5 receptor CD28H in PBMCs also reduced the toxicity of gefitinib on EGFR­mutated NSCLC. Based on these results, it may be proposed that the B7H5/CD28H axis is involved in NSCLC­mediated immunosuppression when EGFR is overactivated. Gefitinib actively inhibits mutated EGFR, which induces B7H5 expression on the cell surface of NSCLC cells, thereby activating CD28H signaling in immune cells, followed by enhanced cytotoxicity against NSCLC. The present study not only provided new insight into the immune evasion mechanism mediated by EGFR mutations but also identified new targets for immune therapy.

WZ4003 sensitizes non-small cell lung cancer cells to gefitinib via inhibition of ARK5 and epithelial-to-mesenchymal transition.

Gefitinib, an epidermal growth factor receptor tyrosine kinase inhibitor, is used as a first-line treatment for advanced non-small cell lung cancer (NSCLC); however, its utility is hampered by the development of chemoresistance. This study aimed to investigate the synergistic role of WZ4003, a novel (nua) kinase (NUAK) inhibitor, in enhancing gefitinib sensitivity in NSCLC cells. Our data indicated WZ4003 enhances the sensitivity of NSCLC cells to gefitinib. We also found ARK5 knockdown in NSCLC cell lines increased their sensitivity to gefitinib. However, WZ4003 did not affect gefitinib sensitivity when ARK5 was knocked down in NSCLC cell lines (using siRNA). Both WZ4003 and ARK5 inhibition suppressed epithelial-to-mesenchymal transition by reducing the expression of vimentin and increasing E-cadherin expression. Together, our results demonstrate WZ4003 plays a vital role in releasing acquired resistance to gefitinib by inhibiting ARK5 and epithelial-to-mesenchymal transition. Therefore, synergistic use of WZ4003 and gefitinib may prevent the development of gefitinib resistance in NSCLC.