Chitosan-based thermosensitive hydrogel with long-term release of murine nerve growth factor for neurotrophic keratopathy

Neurotrophic keratopathy is a persistent defect of the corneal epithelium,with or without stromal ulceration,due to corneal nerve deficiency caused by a variety of etiologies.The treatment options for neurotrophic keratopathy are limited.In this study,an ophthalmic solution was constructed from a chitosan-based thermosensitive hydrogel with long-term release of murine nerve growth factor(CTH-mNGF).Its effectiveness was evaluated in corneal denervation(CD)mice and patients with neurotrophic keratopathy.In the preclinical setting,CTH-mNGF was assessed in a murine corneal denervation model.CTH-mNGF was transparent,thermosensitive,and ensured sustained release of mNGF for over 20 hours on the ocular surface,maintaining the local mNGF concentration around 1300 pg/mL in vivo.Corneal denervation mice treated with CTH-mNGF for 10 days showed a significant increase in corneal nerve area and total corneal nerve length compared with non-treated and CTH treated mice.A subsequent clinical trial of CTH-mNGF was conducted in patients with stage 2 or 3 neurotrophic keratopathy.Patients received topical CTH-mNGF twice daily for 8 weeks.Fluorescein sodium images,Schirmer’s test,intraocular pressure,Cochet-Bonnet corneal perception test,and best corrected visual acuity were evaluated.In total,six patients(total of seven eyes)diagnosed with neurotrophic keratopathy were enrolled.After 8 weeks of CTH-mNGF treatment,all participants showed a decreased area of corneal epithelial defect,as stained by fluorescence.Overall,six out of seven eyes had fluorescence staining scores<5.Moreover,best corrected visual acuity,intraocular pressure,Schirmer’s test and Cochet-Bonnet corneal perception test results showed no significant improvement.An increase in corneal nerve density was observed by in vivo confocal microscopy after 8 weeks of CTH-mNGF treatment in three out of seven eyes.This study demonstrates that CTH-mNGF is transparent,thermosensitive,and has sustained-release properties.Its effectiveness in healing corneal epithelial defects in all eyes with neurotrophic keratopathy suggests CTH-mNGF has promising application prospects in the treatment of neurotrophic keratopathy,being convenient and cost effective.

Uncoupling neurotrophic function from nociception of nerve growth factor: what can be learned from a rare human disease?

Nerve growth factor(NGF) is a powerful trophic factor that provides essential support for the survival and differentiation of sympathetic and sensory neurons during development. However, NGF also activates nociceptors contributing significantly to inflammatory pain and neuropathic pain after tissue injury. As such anti-NGF based therapies represent a promising strategy for pain management. Because of dose-dependent serious side effects such as back pain, injection site hyperalgesia, clinical trials of using NGF to treat various disorders such as diabetic neuropathies, chemotherapy-induced and human immunodeficiency virus-associated peripheral neuropathies were all discontinued. Thus far, worldwide clinical applications of NGF in treating patients are very limited except in China. Hereditary sensory autonomic neuropathy type V(HSAN V) is an extremely rare disease. Genetic analyses have revealed that HSAN V is associated with autosomal recessive mutations in NGF. One of the mutations occurred at the 100^(th) position of mature NGF resulting in a change of residue from arginine to tryptophan(R100W). Although those HSAN V patients associated with the NGF^(R100W) mutation suffer from severe loss of deep pain, bone fractures and joint destruction, interestingly patients with the NGF^(R100W) mutation do not show apparent cognitive deficits, suggesting important trophic support function is preserved. We believe that NGF^(R100W) provides an ideal tool to uncouple the two important functions of NGF: trophic versus nociceptive. Studies from investigators including ourselves have indeed confirmed in animal testing that the NGF^(R100W) no longer induced pain. More importantly, the trophic function seemed to be largely preserved in NGF harboring the R100W mutation. On the mechanistic level, we found that the NGF^(R100W) mutation was capable of binding to and signaling through the tyrosine receptor kinase A receptor. But its ability to bind to and activate the 75 kDa neurotrophic factor was significantly diminished. The significance of these findings is at least two folds: 1) the NGF^(R100W) mutation can be used as an alternative to the wildtype NGF to treat human conditions without eliciting pain; and 2) the 75 kDa neurotrophic factor may serve as a novel target for pain management. We will discuss all the details in this mini-review.

Effect of Human Cytomegalovirus Infection on Nerve Growth Factor Expression in Human Glioma U251 Cells

Objective To explore the change of endogenic nerve growth factor （NGF） expression in human glioma cells infected with human cytomegalovirus （HCMV）. Methods U251 cells were cultured in RPMI 1640 culture medium and infected with HCMV AD 169 strain in vitro to establish a cell model of viral infection. Morphologic changes of U251 cells were observed under inverted microscope before and after infection with HCMV. Expression of NGF gene and protein of cells was detected by RT-PCR and Western blotting before and after infection with HCMV. Results The cytopathic effects of HCMV-infected cells appeared on day 5 after infection. However, differential NGF expression was evident on day 7. NGF expression was decreased significantly in U251 cells on day 7 after infection in comparison with control group （P〈0.05）. Conclusion HCMV can down-regulate endogenous NGF levels in human glioma cell line U251.

Expression and Purification of Active Recombinant Human Nerve Growth Factor from Escherichia coli

Introduction Nerve growth factor （NGF） was first discovered and purified by Rita Levi-Montalcini and Stanley Cohen in the 1950s. It represents the first cellular growth factor ever discovered and involved in the gl-owth ,survival, and differentiation of specific nerve cell populations. Although animal tests and trials indicate that rhNGF could be ment for diabetic and HIV-related phase- Ⅱ clinical an effective treatneuropathies , a large-scale phase-Ⅲ clinical trial has failed to give similar result. NGF isolated from the mouse submaxillary gland has been widely used clinically in China for the treatment of peripheral neuropathy,

Recombinant human fibroblast growth factor-2 promotes nerve regeneration and functional recovery after mental nerve crush injury

Several studies have shown that fibroblast growth factor-2 （FGF2） can directly affect axon regeneration after peripheral nerve damage. In this study, we performed sensory tests and histological analyses to study the effect of recombinant human FGF-2 （rhFGF2） treatment on damaged mental nerves. The mental nerves of 6-week-old male Sprague-Dawley rats were crush-injured for 1 minute and then treated with 10 or 50 μg/mL rhFGF2 or PBS in crush injury area with a mini Osmotic pump. Sensory test using von Frey filaments at 1 week revealed the presence of sensory degeneration based on decreased gap score and increased difference score. However, at 2 weeks, the gap score and difference score were significantly rebounded in the mental nerve crush group treated with 10 μg/mL rhFGF2. Interestingly, treatment with 10 μg/mL rhFGF had a more obviously positive effect on the gap score than treatment with 50 μg/mL rhFGF2. In addition, retrograde neuronal tracing with Dil revealed a significant increase in nerve regeneration in the trigeminal ganglion at 2 and 4 weeks in the rhFGF2 groups （10 μg/mL and 50 μg/mL） than in the PBS group. The 10 μg/mL rhFGF2 group also showed an obviously robust regeneration in axon density in the mental nerve at 4 weeks. Our results demonstrate that 10 μg/mL rhFGF induces mental nerve regeneration and sensory recovery after mental nerve crush injury.

Clinical observation of recombinant human nerve growth factor in the treatment of neurotrophic keratitis

AIM:To characterize changes of corneal nerve morphology and tear indices in patients with neurotrophic keratitis(NK)treated with recombinant human nerve growth factor(rhNGF).METHODS:In a prospective observational study,six patients(nine eyes)were locally treated with rhNGF.Visual acuity,corneal fluorescein staining score,the heights of the tear river,lipid layer thickness(LLT),tear ferning(TF)test,conjunctival impression cytology(CIC)examination,the densities of cornea subbasal nerve fibers were determined before and after treatment.RESULTS:Compared with baseline,there was a significant difference in corneal fluorescence staining scores(P<0.01);all patient corneal epithelial defects recovered completely within 8wk,but there was no significant improvement in the height of the tear river(P=0.202).LLT was significantly increased when compared with baseline(P=0.042);however,the function of conjunctival goblet cells and mucin content did not significantly improve using the TF test and CIC examination(P=0.557,P=0.539).After 8wk of treatment,the average corneal subbasal nerve fiber density increased significantly(P<0.01),as did the number of corneal nerve fiber branches(P=0.001).CONCLUSION:RhNGF can increase the density of corneal subbasal nerve fibers,promote the healing of persistent corneal epithelial defects and corneal ulcers in patients with NK,also improving tear function partially.

Nuclear-targeted therapy of nerve growth factor conjugated with ^(125)I for human glioma U251 cells

The present study investigated the nuclear transportation phenomenon of ^125I-nerve growth factor （NGF） and the DNA-damaging changes to U251 cells using microautoradiography and single cell electrophoresis. The results showed that ^125I-NGF inhibited the survival of p53 mutant U251 human glioma cell/tumor and enhanced the therapeutic effectiveness of vincristine in in vivo and in vitro models. In vitro experiments showed ^125I-NGF was transported into the nucleus and damaged the DNA in U251 cells. Moreover, ^125I-NGF locked the U251 cells in the G2 phase. Further investigation showed that ^125I-NGF decreased cyclin B1 protein levels in a dose dependent manner, but the level of cyclin B1 mRNA expression remained unchanged. ^125I-NGF increased phosphorylated Chkl, Chk2 and Cdc25c protein levels in U251 cells, but did not influence p53 and p21 protein expression. Moreover, ^125I-NGF and vincristine exhibited synergistic effects on reducing cyclin B1 protein levels. These results indicate that ^125I-NGF can provide anti-tumor effects by activating the ATM and ATR pathways through DNA damage.

Adenovirus-mediated human β-nerve growth factor gene transfer has a protective effect on cochlear spiral ganglion after blast exposure

Objective:To study whether adenovirus-mediated human β-nerve growth factor (Ad-hNGFβ) gene has any protective effect on blast hearing impairment. Methods:Deafness was induced by blast exposure (172.0 dB) in 30 healthy guinea pigs. On day 7 of blast exposure, Ad-hNGFβ was infused into the perilymphatic space of 20 animals as the study group (hNGFβ group), and artificial perilymph fluid (APF) was infused into the perilymphatic space of the other 10 animals as the control group. At weeks 1, 4 and 8 after blast exposure, the animals were sacrificed and the cochleae were removed for immunohistochemical and HE stainings. Results: Expression of Ad-hNGFβ protein was detected in each turn of the cochlea at the 1st week, with almost equal intensity in all turns. At the 4th week, the reactive intensity of the expression of Ad-hNGFβ protein decreased. At the 8th week, no expression was detectable. The results of HE staining showed that the amount of spiral ganglions in hNGFβ group was significantly greater than that of the control group at week 4 (P<0.01). Conclusion: Ad-hNGFβ can be expressed at a high level and for a relatively long period in the blast impaired cochlea, suggesting that Ad-hNGFβ has a protective effect on cochlear spiral ganglion cells after blast exposure and the efficient gene transfer into cochlea had been achieved without toxicity.

Effects of Nerve Growth Factor on Proliferation and DNA Synthesis of Cultured Human Fetal Retinal Pigment Epithelium Cells

Objective: To investigate the effects of nerve growth factor(NGF)on proliferation and DNAthesis of cultured human fetal retinal pigment epithelium (RPE)cells in vitro.Methods: Primary culture and subculture of human fetal retinal pigment epithelium cellswere established in vitro first. Cultured RPE cells were treated with NGF by variousconcentrations 0μg/L, 50μg/L, 100μg/L, 200μg/L and 300μg/L(final concentration)for 48 hs.After 48 hs, cells proliferation was measured with methyl thiazolyl tetrazolium(MTT)assay method and the amount of DNA was determined by the absorbance at 280nm of nucleic acid & protein analysis.Results: The A values of 100 μg/L, 200 μg/L, 300 μg/L NGF was(0. 213 7 ± 0. 23 3),(0. 218 8 ±0. 018 1), (0. 232 2 ±0. 016 4) as compared with(0. 189 7 ±0. 015 2) of Avalue of 0 μg/L NGF respectively, q value was 3.63,4.40, 6. 42 and P value was0. 015, 0. 000, 0. 000(q-test). The DNA concentrations of 100 μg/L, 200 μg/L, 300μg/L and 400 μg/L NGF was (981. 220 4 ± 123.535 7), (1 375. 848 4 ±244. 471 8),(1 658.707 1 ± 176. 938 1), (2 353.086 3 ±609. 906 4) μg/ml as compared with(666. 818 8 ± 141. 330 2) μg/ml of DNA concentration of 0 μg/L NGF respectively, qvalue was 3.63,8.20,11.47,19.46, P value was 0. 024,0. 000,0. 000,0. 000 (q-test).Conclusion: The data suggested that NGF could stimulate the proliferation and DNAsynthesis of cultured of hRPE cells in vitro in a dose-dependent manner.

Construction of recombinant human nerve growth factor beta adenovirus and evaluation of its function An in vitro and in vivo study

Exogenous delivery of nerve growth factor （NGF） promotes neural regeneration. However, the short half-life limits delivery efficacy. Therefore, a long-term, efficient, local delivery tool or scheme is needed. The purpose of this study was to construct a functioning, recombinant, adenoviral vector carrying human NGF-β （hNGF-β） DNA, and to measure expression of the constructed vector in vitro and in vivo. rhNGF-β adenoviral vector containing full-length hNGF-β cDNA was generated by homologous recombination in Escherichia CoIL The rhNGF-β adenovirus was packaged and amplified in human embryonic kidney HEK293 cells. Transformation efficiency, expression and function of rhNGF-β adenovirus for primary Schwann cells, Schwann cell lines, human embryonic kidney HEK 293 cells, CRH myoblasts, and NIH3T3 fibroblasts were evaluated. Subsequently, expression of rhNGF-β adenovirus at the peripheral nerve of rat was also assessed. Recombinant adenoviral vector carrying hNGF-β was successfully constructed and confirmed by restriction endonuclease analysis and DNA sequence analysis. Green fluorescent protein expression was observed in 90% of rhNGF-β adenovirus-infected cells （primary Schwann cells, Schwann cell line, human embryonic kidney HEK 293 cells, CRH myoblasts, and NIH3T3 fibroblasts） compared with non-infected cells. Total mRNA isolated from rhNGF-β adenovirus-infected cells exhibited strong expression. Maximum NGF release was induced by primary cultured Schwann cells at 4 days after infection, which steadily continued for 14 days. PC-12 cells exposed to media conditioned with rhNGF-β adenovirus-infected Schwann cells exhibited increased neurite extension. In vivo experiment revealed that the injected rhNGF-β adenovirus was transfected into the cells at the injected site and promoted expression of NGF, p75NTR and brain derived neurotrophic factor at the sciatic nerve and dorsal root ganglia.

Effects of Nerve Growth Factor on NMDA Receptor 1 and Neuronal Nitric Oxide Production after Spinal Cord Injury in Rats

Objective:To explore the protective mechanisms of nerve growth factor (NGF) on spinal cord injury (SCI) and provide theoretical basis for its clinical application. Methods: The SCI of Wistar rats was done by Allens weight dropping way by a 10 g×2.5 cm impact on the posterior of spinal cord T 8. NGF (3 g/L, 20 μl) or normal saline was injected through catheter into subarachnoid space 2, 4, 8, 12 and 24 h after SCI. The expression of N-methyl-D-asparate receptor 1 (NMDAR 1) and neuronal constitutive nitric oxide synthase (ncNOS) mRNA in rat spinal cord was detected by in situ hybridization. Results: Abnormal expression of NMDAR 1 and ncNOS mRNA appeared in spinal ventral horn motorneuron in injured rats, as compared with that in control group. The expression of NMDAR 1 and ncNOS mRNA in NGF group was significantly lower than that in saline group (P<0.01). Conclusion: NGF can protect spinal cord against injury in vivo. One of the mechanisms is that NGF can prohibit NMDAR 1 and nitric oxide (NO) production after spinal cord injury.

Regulatory effect of nerve growth factor on release of substance P in cultured dorsal root ganglion neurons of rat

Objective To investigate the regulatory effects of nerve growth factor （NGF） on basal and capsaicin-induced release of neuropeptide substance P （SP） in primary cultured embryonic rat dorsal root ganglion （DRG） neurons. Methods DRGs were dissected from 15-day-old embryonic Wistar rats. DRG neurons were dissociated and cultured, and then exposed to different concentrations of NGF （10 ng/mL, 30 ng/mL, or 100 ng/mL） for 72 h. The neurons cultured in media without NGF served as control. RT-PCR were used for detecting the mRNAs of SP and vanilloid receptor 1 （VR1） in the DRG neurons. The SP basal and capsaicin （100 nmol/L）-induced release in the culture were measured by radioimmunoassay （RIA）. Results SP mRNA and VR1 mRNA expression increased in primary cultured DRG neurons in a dose-dependent manner of NGF. Both basal release and capsaicin-evoked release of SP increased in NGF-treated DRG neurons compared with in control group. The capsaicin-evoked release of SP also increased in a dose-dependent manner of NGF. Conclusion NGF may promote both basal release and capsaicin-evoked release of SP. NGF might increase the sensitivity of nociceptors by increasing the SP mRNA or VR1 mRNA.

Human umbilical cord mesenchymal stem cell-derived exosomes loaded into a composite conduit promote functional recovery after peripheral nerve injury in rats

Complete transverse injury of peripheral nerves is challenging to treat.Exosomes secreted by human umbilical cord mesenchymal stem cells are considered to play an important role in intercellular communication and regulate tissue regeneration.In previous studies,a collagen/hyaluronic acid sponge was shown to provide a suitable regeneration environment for Schwann cell proliferation and to promote axonal regeneration.This three-dimensional(3D)composite conduit contains a collagen/hyaluronic acid inner sponge enclosed in an electrospun hollow poly(lactic-co-glycolic acid)tube.However,whether there is a synergy between the 3D composite conduit and exosomes in the repair of peripheral nerve injury remains unknown.In this study,we tested a comprehensive strategy for repairing long-gap(10 mm)peripheral nerve injury that combined the 3D composite conduit with human umbilical cord mesenchymal stem cell-derived exosomes.Repair effectiveness was evaluated by sciatic functional index,sciatic nerve compound muscle action potential recording,recovery of muscle mass,measuring the cross-sectional area of the muscle fiber,Masson trichrome staining,and transmission electron microscopy of the regenerated nerve in rats.The results showed that transplantation of the 3D composite conduit loaded with human umbilical cord mesenchymal stem cell-derived exosomes promoted peripheral nerve regeneration and restoration of motor function,similar to autograft transplantation.More CD31-positive endothelial cells were observed in the regenerated nerve after transplantation of the loaded conduit than after transplantation of the conduit without exosomes,which may have contributed to the observed increase in axon regeneration and distal nerve reconnection.Therefore,the use of a 3D composite conduit loaded with human umbilical cord mesenchymal stem cell-derived exosomes represents a promising cell-free therapeutic option for the treatment of peripheral nerve injury.

Effect of resuscitation after selective cerebral ultraprofound hypothermia on expressions of nerve growth factor and glial cell line-derived neurotrophic factor in the brain of monkey

Objective To investigate the expression of nerve growth factor （NGF） and glial cell line-derived neurotrophic factor （GDNF） in monkeys of resuscitation after selective cerebral ultraprofound hypothermia and blood flow occlusion. Methods The monkeys were immediately removed brain after death in operation of group A （identical temperature perfusion group） and group B （ultraprofound hypothermia perfusion group）. Immunohistochemical technique was used to determine frontal cellular expression of NGF and GDNF. Statistics were analyzed by ANOVA analyses with significance level at P 〈 0.05. Results The expressions of NGF and GDNF in the group B were significantly higher than those in the group A （P 〈 0.05）. Conclusion NGF and GDNF increased significantly in the monkeys of resuscitation after selective cerebral ultraprofound hypothermia and blood flow occlusion. It may be a protective mechanism for neuron survival and neural function recovery.

Isolation and Evaluation of Nerve Growth Factor

Objective: to obtain the high purified and active nerve growth factor (NGF) from mouse submaxillary glands. Methods: NGF was prepared from mouse submaxillary glands by the way of elution with CM 52 column. The molecular weight and purification of NGF were detected by SDS-PAGE polyacrylamide gel electrophoresis. The biological activity of NGF was verified thorough culturing DRG. Results: About 14 kDa stained band was observed on SDS-PAGE and it promoted proliferation of dorsal root gang lia (DRG). Conclusion: Good quality of NGF could be obtained with these methods.

PRaG 3.0 therapy for human epidermal growth factor receptor 2-positive metastatic pancreatic ductal adenocarcinoma:A case report

BACKGROUND Pancreatic ductal adenocarcinoma(PDAC)is a highly fatal disease with limited effective treatment especially after first-line chemotherapy.The human epidermal growth factor receptor 2(HER-2)immunohistochemistry(IHC)positive is associated with more aggressive clinical behavior and shorter overall survival in PDAC.CASE SUMMARY We present a case of multiple metastatic PDAC with IHC mismatch repair proficient but HER-2 IHC weakly positive at diagnosis that didn’t have tumor regression after first-line nab-paclitaxel plus gemcitabine and PD-1 inhibitor treatment.A novel combination therapy PRaG 3.0 of RC48(HER2-antibody-drug conjugate),radio-therapy,PD-1 inhibitor,granulocyte-macrophage colony-stimulating factor and interleukin-2 was then applied as second-line therapy and the patient had confirmed good partial response with progress-free-survival of 6.5 months and overall survival of 14.2 month.She had not developed any grade 2 or above treatment-related adverse events at any point.Percentage of peripheral CD8^(+) Temra and CD4^(+) Temra were increased during first two activation cycles of PRaG 3.0 treatment containing radiotherapy but deceased to the baseline during the maintenance cycles containing no radiotherapy.CONCLUSION PRaG 3.0 might be a novel strategy for HER2-positive metastatic PDAC patients who failed from previous first-line approach and even PD-1 immunotherapy but needs more data in prospective trials.

Inetetamab combined with S-1 and oxaliplatin as first-line treatment for human epidermal growth factor receptor 2-positive gastric cancer

BACKGROUND Patients with human epidermal growth factor receptor 2(HER2)-positive advanced gastric cancer have poor outcomes.Trastuzumab combined with chemotherapy is the first-line standard treatment for HER2-positive advanced gastric cancer.Inetetamab is a novel anti-HER2 drug,and its efficacy and safety in gastric cancer have not yet been reported.AIM To evaluate the efficacy and safety of the S-1 plus oxaliplatin(SOX)regimen combined with inetetamab as a first-line treatment for HER2-positive advanced gastric cancer.METHODS Thirty-eight patients with HER2-positive advanced gastric cancer or gastroeso-phageal junction adenocarcinoma were randomly divided into two groups:One group received inetetamab combined with the SOX regimen,and the other group received trastuzumab combined with the SOX regimen.After 4-6 cycles,patients with stable disease received maintenance therapy.The primary endpoints were progression-free survival(PFS)and overall survival(OS),and the secondary endpoints were the objective response rate,disease control rate,and adverse events(AEs).RESULTS Thirty-seven patients completed the trial,with 18 patients in the inetetamab group and 19 patients in the trastuzumab group.In the inetetamab group,the median PFS was 8.5 months,whereas it was 7.3 months in the trastuzumab group(P=0.046);this difference was significant.The median OS in the inetetamab group vs the trastuzumab group was 15.4 months vs 14.3 months(P=0.33),and the objective response rate was 50%vs 42%(P=0.63),respectively;these differences were not significant.Common AEs included leukopenia,thrombocytopenia,nausea,and vomiting.The incidence rates of grade≥3 AEs were 56%in the inetetamab group and 47%in the trastuzumab group(P=0.63),with no significant difference.CONCLUSION In the first-line treatment of HER2-positive advanced gastric cancer,inetetamab and trastuzumab showed comparable efficacy.The inetetamab group showed superior PFS,and both groups had good safety.

BIRC3 induces the phosphoinositide 3-kinase-Akt pathway activation to promote trastuzumab resistance in human epidermal growth factor receptor 2-positive gastric cancer

BACKGROUND Trastuzumab-targeted therapy is currently the standard of care for advanced human epidermal growth factor receptor 2(HER2)-positive gastric cancer.However,the emergence of resistance to trastuzumab poses significant challenges.AIM To identify the key genes associated with trastuzumab resistance.These results provide a basis for the development of interventions to address drug resistance and improve patient outcomes.METHODS High-throughput sequencing and bioinformatics were used to identify the differentially expressed pivotal gene BIRC3 and delineate its potential function and pathway regulation.Tumor samples were collected from patients with HER2-positive gastric cancer to evaluate the correlation between BIRC3 expression and trastuzumab resistance.We established gastric cancer cell lines with both highly expressed and suppressed levels of BIRC3,followed by comprehensive in vitro and in vivo experiments to confirm the involvement of BIRC3 in trastuzumab resistance and to elucidate its underlying mechanisms.RESULTS In patients with HER2-positive gastric cancer,there is a significant correlation between elevated BIRC3 expression in tumor tissues and higher T stage,tumor node metastasis stage,as well as poor overall survival and progressionfree survival.BIRC3 is highly expressed in trastuzumab-resistant gastric cancer cell lines,where it inhibits tumor cell apoptosis and enhances trastuzumab resistance by promoting the phosphorylation and activation of the phosphoinositide 3-kinase-Akt(PI3K-AKT)pathway in HER2-positive gastric cancer cells,both in vivo and in vitro.CONCLUSION This study revealed a robust association between high BIRC3 expression and an unfavorable prognosis in patients with HER2-positive gastric cancer.Thus,the high expression of BIRC3 stimulated PI3K-AKT phosphorylation and activation,stimulating the proliferation of HER2-positive tumor cells and suppressing apoptosis,ultimately leading to trastuzumab resistance.

Inetetamab combined with tegafur as second-line treatment for human epidermal growth factor receptor-2-positive gastric cancer: A case report

BACKGROUND Human epidermal growth factor receptor-2(HER-2)plays a vital role in tumor cell proliferation and metastasis.However,the prognosis of HER2-positive gastric cancer is poor.Inetetamab,a novel anti-HER2 targeting drug independently developed in China,exhibits more potent antibody-dependent cell-mediated cytotoxicity than trastuzumab,which is administered as the first-line treatment for HER2-positive gastric cancer in combination with chemotherapy.In this case,the efficacy and safety of inetetamab combined with tegafur was investigated as a second-line treatment for HER2-positive gastric cancer.CASE SUMMARY A 52-year-old male patient with HER2-positive gastric cancer presented with abdominal distension,poor appetite,and fatigue two years after receiving six cycles of oxaliplatin combined with tegafur as first-line treatment after surgery,followed by tegafur monotherapy for six months.The patient was diagnosed with postoperative recurrence of gastric adenocarcinoma.He received 17 cycles of a combination of inetetamab,an innovative domestically developed anti-HER2 monoclonal antibody,and tegafur chemotherapy as the second-line treatment(inetetamab 200 mg on day 1,every 3 wk combined with tegafur twice daily on days 1–14,every 3 wk).Evaluation of the efficacy of the second-line treatment revealed that the patient achieved a stable condition and progression-free survival of 17 months.He tolerated the treatment well without exhibiting any grade 3-4 adverse events.CONCLUSION Inetetamab combined with chemotherapy for the treatment of metastatic HER2-positive gastric cancer demonstrates significant survival benefits and acceptable safety.

Advances in targeted therapy for human epidermal growth factor receptor 2 positive in advanced gastric cancer

Emerging therapeutic methods represented by targeted therapy are effective supplements to traditional first-line chemoradiotherapy resistance.Human epidermal growth factor receptor 2(HER2)is one of the most important targets in targeted therapy for gastric cancer.Trastuzumab combined with chemotherapy has been used as the first-line treatment for advanced gastric cancer.The safety and efficacy of pertuzumab and margetuximab in the treatment of gastric cancer have been verified.However,monoclonal antibodies,due to their large molecular weight,inability to penetrate the blood-brain barrier,and drug resistance,lead to decreased therapeutic efficacy,so it is necessary to explore the efficacy of other HER2-targeting therapies in gastric cancer.Small-molecule tyrosine kinase inhibitors,such as lapatinib and pyrrotinib,have the advantages of small molecular weight,penetrating the blood-brain barrier and high oral bioavailability,and are expected to become the drugs of choice for perioperative treatment and neoadjuvant therapy of gastric cancer after validation by large-scale clinical trials in the future.Antibo-drug conjugate,such as T-DM1 and T-DXd,can overcome the resistance of monoclonal antibodies despite their different mechanisms of tumor killing,and are a supplement for the treatment of patients who have failed the treatment of monoclonal antibodies such as trastuzumab.Therefore,after more detailed stratification of gastric cancer patients,various gastric cancer drugs targeting HER2 are expected to play a more significant role.