Anorectal malignant melanomas: Retrospective experience with surgical management

AIM: To present the experience and outcomes of the surgical treatment for the patients with anorectal melanoma from the Cancer Hospital, Chinese Academy of Medical Sciences. METHODS: Medical records of the diagnosis, surgery, and follow-up of 56 patients with anorectal melanoma who underwent surgery between 1975 and 2008 were retrospectively reviewed. The factors predictive for the survival rate of these patients were identified using multivariate analysis. RESULTS: The 5-year survival rate of the 56 patients with anorectal melanoma was 20%, 36 patients underwent abdominoperineal resection (APR) and 20 patients underwent wide local excision (WLE). The rates of local recurrence of the APR and WLE groups were 16.13% (5/36) and 68.75% (13/20), (P = 0.001), and the median survival time was 22 mo and 21 mo, respectively (P = 0.481). Univariate survival analysis demonstrated that the number of tumor and the depth of invasion had significant effects on the survival (P < 0.05). Multivariate analysis showed that the number of tumor [P = 0.017, 95% confidence interval (CI) = 1.273-11.075] and the depth of invasion (P = 0.015, 95% CI = 1.249-7.591) were independent prognostic factors influencing the survival rate. CONCLUSION: Complete or R0 resection is the first choice of treatment for anorectal melanoma, prognosis is poor regardless of surgical approach, and early diagnosis is the key to improved survival rate for patients with anorectal melanoma.

Novel biomarkers and therapeutic targets for optimizing the therapeutic management of melanomas

Cutaneous malignant melanoma is the most aggressive form of skin cancer with an extremely poor survival rate for the patients diagnosed with locally invasive and metastatic disease states. Intensive research has led in last few years to an improvement of the early detection and curative treatment of primary cutaneous melanomas that are confined to the skin by tumor surgical resection. However, locally advanced and disseminated melanomas are generally resistant to conventional treatments, including ionizing radiation, systemic chemotherapy, immunotherapy and/or adjuvant stem cellbased therapies, and result in the death of patients. The rapid progression of primary melanomas to locally invasive and/or metastatic disease states remains a major obstacle for an early effective diagnosis and a curative therapeutic intervention for melanoma patients. Importantly, recent advances in the melanoma research have led to the identification of different gene products that are often implicated in the malignant transforma-tion of melanocytic cells into melanoma cells, including melanoma stem/progenitor cells, during melanoma initiation and progression to locally advanced and metastatic disease states. The frequent deregulated genes products encompass the oncogenic B-Raf V600 E and N-RasQ 61 R mutants, different receptor tyrosine kinases and developmental pathways such as epidermal growth factor receptor(EGFR), stem cell-like factor(SCF) receptor KIT, hedgehog, Wnt/β-catenin, Notch, stromal cell-derived factor-1(SDF-1)/CXC chemokine receptor-4(CXCR4) and vascular endothelial growth factor(VEGF)/VEGFR receptor. These growth factors can cooperate to activate distinct tumorigenic downstream signaling elements and epithelial-mesenchymal transition(EMT)-associated molecules, including phosphatidylinositol 3'-kinase(PI3K)/Akt/ molecular target of rapamycin(mT OR), nuclear factor-kappaB(NF-κB), macrophage inhibitory cytokine-1(MIC-1), vimentin, snail and twist. Of therapeutic relevance, these deregulated signal transduction components constitute new potential biomarkers and therapeutic targets of great clinical interest for improving the efficacy of current diagnostic and prognostic methods and management of patients diagnosed with locally advanced, metastatic and/or relapsed melanomas.

Malignant gastrointestinal melanomas of unknown origin: Should it be considered primary?

We read with interest the article entitled： ‘Jejuno-jejunal invagination due to intestinal melanoma’ by Resta , et al. They reported a rare clinical case of a young woman with a bleeding jejunal melanoma, whose early clinical presentation was an intestinal invagination. The article is also referred to the rarity of gastrointestinal melanomas as well as their possible primary nature.

Unusual clinical course of metachronous melanomas of the upper digestive system

Melanoma of the gastrointestinal tract is a rare, highly malignant neoplasm of poor prognosis. This is description of an unusual case of surgically treated patient with two metachronous malignant melanomas of the stomach and the esophagus. The former lesion was located in the cardia and effectively treated with RO total gastrectomy. The latter was recognized after 67 mo and appeared as irregular, flat, pigmented areas located in the mid esophagus. Subtotal esophagectomy via right-sided thoracotomy, laparotomy and left-sided cervicotomy was performed, but neoplastic cells were found in distal margin (R1). Fourteen months after esophagectomy multiple lung metastases were detected. Patient.died 2 mo later.

Multiple synchronous anorectal melanomas with different colors: A case report

BACKGROUND Anorectal melanoma (AM) is an extremely rare malignant tumor originating from anorectal melanocytes with a poor prognosis. AM has been reported to have a much lower incidence than cutaneous or choroid melanoma, accounting for 0.4%-1.6% of all melanomas. CASE SUMMARY We report a 76-year-old female patient diagnosed with anorectal malignant melanoma by colonoscopy and biopsy. Intraoperative examination revealed two distinct anorectal tumors, one melanotic and another amelanotic, as well as two pigmented mucosal zones at the dentate line level. Abdominal perineal resection was performed. A pathological report confirmed all four lesions to be melanomas. Postoperatively, we followed an immunotherapy protocol targeting PD-1 (nivolumab). The patient had 24 mo of disease-free follow-up upon completion of nivolumab treatment. CONCLUSION This is the first reported case presenting coexistence of pigmented and unpigmented AMs in the same patient.

Targeted therapy for malignant ocular melanomas

In a comprehensive literature review,PubMed,Embasem and Web of Science were searched for studies examining targeted therapy of ocular malignant melanomas to present and discuss targeted therapy treatment options of ocular tumors,mainly conjunctival and uveal melanoma(UM).Conjunctival malignant melanomas showed similarities in clinical and genetic aspects with cutaneous melanomas.Many therapies with checkpoint inhibitors already established for cutaneous melanomas may be a treatment option for conjunctival malignant melanomas with shared traits.Existing targeted therapies are for example checkpoint inhibitors like pembrolizumab or nivolumab.As a corollary,due to marked differences in clinics and genetics between UMs and conjunctival melanomas(CMs)or cutaneous melanomas,it has remained elusive whether the available possibilities of molecular targeted therapy will be an option for the therapy of metastasizing UMs.Possible novel ways of treating UM are being explored.Fotemustine or the inoculation of dendritic cells with tumorous RNA or sunitinib in combination with cisplatin and or tamoxifen may be used in future to treat UM.While CM are treatable using targeted therapies,UM have not been researched enough to find working targeted therapy options.Further research has to be done in order to find acceptable treatment options.

PYK2 mediates the BRAF inhibitor (vermurafenib)-induced invadopodia formation and metastasis in melanomas

Objective:The BRAF inhibitor,vemurafenib,has been widely used in the treatment of patients with melanoma-bearing BRAFV600E mutations.While the initial response to vemurafenib is usually excellent,the majority of patients eventually develop resistance and metastatic disease.However,the underlying molecular mechanism remains elusive.The objective of this study was therefore to identify additional molecular targets responsible for vemurafenib resistance.Methods:Western blots and immunohistochemistry analyses were used to evaluate expressions of PYK2 and p-PYK2 in cultured cells and melanoma tissue microarrays.The relationships of p-PYK2 with clinicopathological parameters were statistically analyzed.Invadopodia cell invasion,and a Ca2+assay were used to determine the effect of vemurafenib resistance-induced p-PYK2 on melanoma progression.A mouse model was used to assess the effects of PYK2 on melanoma metastasis.Results:Elevated p-PYK2 levels were detected in vemurafenib-resistant melanoma cells,and PYK2 was shown to regulate invadopodia formation in melanoma cells.Vemurafenib triggered invadopodia formation by activation of PYK2.Inhibition of PYK2 with either shRNA or the small molecule inhibitor,PF562711,dramatically reduced vemurafenib-induced invadopodia formation.Furthermore,knockdown of PYK2 significantly reduced melanoma lung metastasis in vivo.Increased expressions of p-PYK2 in melanoma patients were positively correlated with advanced stage(P=0.002),metastasis(P<0.001),and Clark grade(P<0.001),and were also associated with short overall survival[hazard ratio(HR)=3.304,P=0.007]and progression-free survival(HR=2.930,P=0.001).Conclusions:PYK2 mediated vemurafenib-induced melanoma cell migration and invasion.Inhibition of PYK2 resensitized melanoma cells to vemurafenib.Phospho-PYK2 was a prognostic biomarker in melanoma patients.

Secondary endoresection for previously treated choroidal melanomas with a non-responsive course and persistent exudative retinal detachment

AIM:To evaluate the results and complications of secondary endoresection via pars plana vitrectomy for choroidal melanoma and review the previously reported endoresection studies on the treatment of choroidal melanoma.METHODS:The medical records of 6 patients with choroidal melanoma who underwent secondary endoresection between March 2012 and March 2020 were retrospectively reviewed.The indications for secondary endoresection were progressive or recurrent tumor and severe exudative retinal detachment after previous treatment with plaque radiotherapy/Cyberknife radiosurgery/transpupillary thermotherapy(TTT).RESULTS:Before endoresection,2 eyes had Iodine-125 plaque radiotherapy and TTT,1 eye had Ruthenium-106 plaque radiotherapy and TTT,1 eye had Cyberknife radiosurgery and TTT,1 eye had Cyberknife radiosurgery,and 1 eye had TTT only.Preoperative visual acuity ranged from 20/63 to 20/1600(Snellen) and from 0.5 to 1.9(mean:1.1) on the log MAR scale.The mean tumor base diameters were 9.5×8.7 mm and the mean tumor thickness was 5.4 mm.After secondary endoresection,transient vitreous hemorrhage developed in 2(33.3%) eyes and retinal detachment in 1(16.7%) eye.Cytopathological examination revealed epithelioid cell melanoma in 4(66.7%) eyes and mixed cell melanoma in 1(16.7%).Melanoma cell type was not specified in 1(16.7%) eye.At a mean follow-up of 49.6 mo(range:16-90 mo),mean visual acuity did not improve and 1 eye was enucleated due to tumor recurrence.Final visual acuity ranged from 20/63 to 20/1600(Snellen) and from 0.5 to 1.9(mean:1.2) on the log MAR scale.Two patients with choroidal melanoma developed metastasis and eventually expired.CONCLUSION:Secondary endoresection seems to be an effective treatment option for globe salvage in choroidal melanoma not responsive to conventional treatment and displaying persistent exudative retinal detachment.There was no visual acuity increase among the treated eyes but globe salvage was possible in most cases in this study.

Primary Anorectal Melanomas Interest of Targeting C-KIT in Two Cases from a Series of 11 Patients

Background: The anorectal location of melanomas is extremely rare (1% - 3% of all melanomas), and the prognosis remains poor because of the aggressiveness and the high metastatic potential of those tumors. The discovery that the KIT oncogene may be aberrantly activated in a subset of patients with anorectal melanoma creates a realm of possibility for the development of targeted molecular therapy. Aim: to show the epidemiologic, clinico-radiological, histological features and treatment management especially in patients with over-expression of C-KIT treated by Imatinib. Methods: It is a retrospective study conducted in the department of medical oncology at Hassan II University Hospital between January 2007 and January 2012, including all patients with histologically proven melanoma of the anorectal area. Results: 11 cases were collected, with slight female predominance. Nine patients were metastatic at the moment of diagnosis, and only two with local stage, but evolution was marked by local and distant recurrence less than 12 months after abdo-minoperineal resection. First line of chemotherapy was based mainly on paclitaxel, carboplatine and dacarbazine. Response was modest with only 3 partial responses, 4 patients with disease stability, and 4 patients with disease progression. Two patients, with over expression of C-KIT, received Imatinib as second line of treatment with significant improvement of symptoms and radiological response reaching 50%. Seven patients died with a median survival of 11 months from diagnosis to the date of death. Conclusion: Primary anorectal melanomas are very rare, with high aggressiveness and poor prognosis. Treatment management is still a big challenge given to the modest efficacy of conventional chemotherapy. Better understanding of carcinogenesis and signaling pathways will allow development of new targeted therapies.

Molecular and therapeutic landscape of ferroptosis in skin diseases

Regulated cell death(RCD)is a critical physiological process essential in maintaining skin homeostasis.Among the various forms of RCD,ferroptosis stands out due to its distinct features of iron accumulation,lipid peroxidation,and involvement of various inhibitory antioxidant systems.In recent years,an expanding body of research has solidly linked ferroptosis to the emergence of skin disorders.Therefore,understanding the mechanisms underlying ferroptosis in skin diseases is crucial for advancing therapy and prevention strategies.This review commences with a succinct elucidation of the mechanisms that underpin ferroptosis,embarks on a thorough exploration of ferroptosis’s role across a spectrum of skin conditions,encompassing melanoma,psoriasis,systemic lupus erythematosus(SLE),vitiligo,and dermatological ailments precipitated by ultraviolet(UV)exposure,and scrutinizes the potential therapeutic benefits of pharmacological interventions aimed at modulating ferroptosis for the amelioration of skin diseases.

A PET probe targeting polyamine transport system for precise tumor diagnosis and therapy

Polyamine metabolism dysregulation is a hallmark of many cancers,offering a promising avenue for early tumor theranostics.This study presents the development of a nuclear probe derived from spermidine(SPM)for dual-purpose tumor PET imaging and internal radiation therapy.The probe,radiolabeled with either[68Ga]Ga for diagnostic applications or[177Lu]Lu for therapeutic use,was synthesized with exceptional purity,stability,and specific activity.Extensive testing involving 12 different tumor cell lines revealed remarkable specificity towards B16 melanoma cells,showcasing outstanding tumor localization and target-to-non-target ratio.Mechanistic investigations employing polyamines,non-labeled precursor,and polyamine transport system(PTS)inhibitor,consistently affirmed the probe?s targetability through recognition of the PTS.Notably,while previous reports indicated PTS upregulation in various tumor types for targeted therapy,this study observed no positive signals,highlighting a concentration-dependent discrepancy between targeting for therapy and diagnosis.Furthermore,when labeled with[177Lu],the probe demonstrated its therapeutic potential by effectively controlling tumor growth and extending mouse survival.Investigations into biodistribution,excretion,and biosafety in healthy humans laid a robust foundation for clinical translation.This study introduces a versatile SPM-based nuclear probe with applications in precise tumor theranostics,offering promising prospects for clinical implementation.

Biological characteristics and clinical management of uveal and conjunctival melanoma

Uveal and conjunctival melanomas are relatively rare tumors;nonetheless,they pose a significant risk of mortality for a large number of affected individuals.The pathogenesis of melanoma at different sites is very similar,however,the prognosis for patients with ocular melanoma remains unfavourable,primarily due to its distinctive genetic profile and tumor microenvironment.Regardless of considerable advances in understanding the genetic characteristics and biological behaviour,the treatment of uveal and conjunctival melanoma remains a formidable challenge.To enhance the prospect of success,collaborative efforts involving medical professionals and researchers in thefields of ocular biology and oncology are essential.Current data show a lack of well-designed randomized clinical trials and limited benefits in current forms of treatment for these tumors.Despite advancements in the development of effective melanoma therapeutic strategies,all current treatments for uveal melanoma(UM)and conjunctival melanoma(CoM)remain unsatisfactory,resulting in a poor long-term prognosis.Ongoing trials offer hope for positive outcomes in advanced and metastatic tumors.A more comprehensive understanding of the genetic and molecular abnormalities involved in the development and progression of ocular melanomas opens the way for the development of personalized therapy,with various potential therapeutic targets currently under consideration.Increased comprehension of the molecular pathogenesis of UM and CoM and their specificities may aid in the development of new and more effective systemic therapeutic agents,with the hope of improving the prognosis for patients with metastatic disease.

Low-molecular-weight fucoidan inhibits the proliferation of melanoma via Bcl-2 phosphorylation and PTEN/AKT pathway

Fucoidan,a sulfate polysaccharide obtained from brown seaweed,has various bioactive properties,including anti-inflammatory,anti-cancer,anti-viral,anti-oxidant,anti-coagulant,anti-thrombotic,anti-angiogenic,and anti-Helicobacter pylori properties.However,the effects of low-molecular-weight fucoidan(LMW-F)on melanoma cell lines and three dimensional(3D)cell culture models are not well understood.This study aimed to investigate the effects of LMW-F on A375 human melanoma cells and cryopreserved biospecimens derived from patients with advanced melanoma.Ultrasonic wave was used to fragment fucoidan derived from Fucus vesiculosus into smaller LMW-F.MTT and live/dead assays showed that LMW-F inhibited cell proliferation in both A375 cells and patientderived melanoma explants in a 3D-printed collagen scaffold.The PTEN/AKT pathway was found to be involved in the anti-melanoma effects of fucoidan.Western blot analysis revealed that LMW-F reduced the phosphorylation of Bcl-2 at Thr 56,which was associated with the prevention of anti-apoptotic activity of cancer cells.Our findings suggested that LMW-F could enhance anti-melanoma chemotherapy and improve the outcomes of patients with melanoma resistance.

The roles of macrophage migration inhibitory factor in retinal diseases

Macrophage migration inhibitory factor(MIF),a multifunctional cytokine,is secreted by various cells and participates in inflammatory reactions,including innate and adaptive immunity.There are some evidences that MIF is involved in many vitreoretinal diseases.For example,MIF can exacerbate many types of uveitis;measurements of MIF levels can be used to monitor the effectiveness of uveitis treatment.MIF also alleviates trauma-induced and glaucoma-induced optic nerve damage.Furthermore,MIF is critical for retinal/choroidal neovascularization,especially complex neovascularization.MIF exacerbates retinal degeneration;thus,anti-MIF therapy may help to mitigate retinal degeneration.MIF protects uveal melanoma from attacks by natural killer cells.The mechanism underlying the effects of MIF in these diseases has been demonstrated:it binds to cluster of differentiation 74,inhibits the c-Jun N-terminal kinase pathway,and triggers mitogen-activated protein kinases,extracellular signal-regulated kinase-1/2,and the phosphoinositide-3-kinase/Akt pathway.MIF also upregulates Toll-like receptor 4 and activates the nuclear factor kappa-B signaling pathway.This review focuses on the structure and function of MIF and its receptors,including the effects of MIF on uveal inflammation,retinal degeneration,optic neuropathy,retinal/choroidal neovascularization,and uveal melanoma.

CRABP2 regulates infiltration of cancer-associated fibroblasts and immune response in melanoma

Finding biomarkers for immunotherapy is an urgent issue in cancer treatment.Cellular retinoic acid-binding protein 2(CRABP2)is a controversial factor in the occurrence and development of human tumors.However,there is limited research on the relationship between CRABP2 and immunotherapy response.This study found that negative correlations of CRABP2 and immune checkpoint markers(PD-1,PD-L1,and CTLA-4)were observed in breast invasive carcinoma(BRCA),skin cutaneous melanoma(SKCM),stomach adenocarcinoma(STAD)and testicular germ cell tumors(TGCT).In particular,in SKCM patients who were treated with PD-1 inhibitors,high levels of CRABP2 predicted poor prognosis.Additionally,CRABP2 expression was elevated in cancer-associated fibroblasts(CAFs)at the single-cell level.The expression of CRABP2 was positively correlated with markers of CAFs,such as MFAP5,PDPN,ITGA11,PDGFRα/βand THY1 in SKCM.To validate the tumor-promoting effect of CRABP2 in vivo,SKCM xenograft mice models with CRABP2 overexpression have been constructed.These models showed an increase in tumor weight and volume.Enrichment analysis indicated that CRABP2 may be involved in immunerelated pathways of SKCM,such as extracellular matrix(ECM)receptor interaction and epithelial-mesenchymal transition(EMT).The study suggests that CRABP2 may regulate immunotherapy in SKCM patients by influencing infiltration of CAFs.In conclusion,this study provides new insights into the role of CRABP2 in immunotherapy response.The findings suggest that CRABP2 may be a promising biomarker for PD-1 inhibitors in SKCM patients.Further research is needed to confirm these findings and to explore the clinical implications of CRABP2 in immunotherapy.

BET inhibitors potentiate melanoma ferroptosis and immunotherapy through AKR1C2 inhibition

Dear Editor,Ferroptosis,an iron-dependent form of cell death driven by overwhelming lipid peroxidation,represents a vulnerability in cancers,and therapeutic strategies to further potentiate ferroptosis hold great potential for melanoma treatment.

Absent in melanoma 2 attenuates proliferation and migration and promotes apoptosis of human colorectal cancer cells by activating P38MAPK signaling pathway

Colorectal cancer(CRC)stands among the top prevalent cancers worldwide and holds a prominent position as a major contributor to cancer-related mortality globally.Absent in melanoma 2(AIM2),a constituent of the interferoninducible hematopoietic interferon-inducible nuclear antigens with 200 amino acid repeats protein family,contributes to both cancer progression and inflammasome activation.Despite this understanding,the precise biological functions and molecular mechanisms governed by AIM2 in CRC remain elusive.Consequently,this study endeavors to assess AIM2’s expression levels,explore its potential antitumor effects,elucidate associated cancer-related processes,and decipher the underlying signaling pathways in CRC.Our findings showed a reduced AIM2 expression in most CRC cell lines.Elevation of AIM2 levels suppressed CRC cell proliferation and migration,altered cell cycle by inhibiting G1/S transition,and induced cell apoptosis.Further research uncovered the participation of P38 mitogen-activated protein kinase(P38MAPK)in AIM2-mediated modulation of CRC cell apoptosis and proliferation.Altogether,our achievements distinctly underscored AIM2’s antitumor role in CRC.AIM2 overexpression inhibited proliferation and migration and induced apoptosis of CRC cells via activating P38MAPK signaling pathway,indicating AIM2 as a prospective and novel therapeutic target for CRC.

Stem cell technology for antitumor drug loading and delivery in oncology

The main aim of antineoplastic treatment is to maximize patient benefit by augmenting the drug accumulation within affected organs and tissues,thus incrementing drug effects and,at the same time,reducing the damage of non-involved tissues to cytotoxic agents.Mesenchymal stromal cells(MSC)represent a group of undifferentiated multipotent cells presenting wide self-renewal features and the capacity to differentiate into an assortment of mesenchymal family cells.During the last year,they have been proposed as natural carriers for the selective release of antitumor drugs to malignant cll,s thus optimizing cytotoxic action on cancer cll,while significantly reducing adverse side efect on healthy cells.MSC chemotherapeutic drug loading and delivery is an encouraging new area of cell therapy for several tumors,especially for those with unsatisfactory prognosis and limited treatment options available.Although some experim ental models have been sucesfuly developed,phase I dinical studies are needed to confirm this potential application of cell therapy,in particular in the case of primary and secondary lung cancers.

Circ_0053943 complexed with IGF2BP3 drives uveal melanoma progression via regulating N6-methyladenosine modification of Epidermal growth factor receptor

Numerous studies have characterized the critical role of circular RNAs(circRNAs)as regulatory factors in the progression of multiple cancers.However,the biological functions of circRNAs and their underlying molecular mechanisms in the progression of uveal melanoma(UM)remain enigmatic.In this study,we identified a novel circRNA,circ_0053943,through re-analysis of UM microarray data and quantitative RT-PCR.Circ_0053943 was found to be upregulated in UM and to promote the proliferation and metastatic ability of UM cells in both in vitro and in vivo settings.Mechanistically,circ_0053943 was observed to bind to the KH1 and KH2 domains of insulin-like growth factor 2 mRNA-binding protein 3(IGF2BP3),thereby enhancing the function of IGF2BP3 by stabilizing its target mRNA.RNA sequencing assays identified epidermal growth factor receptor(EGFR)as a target gene of circ_0053943 and IGF2BP3 at the transcriptional level.Rescue assays demonstrated that circ_0053943 exerts its biological function by stabilizing EGFR mRNA and regulating the downstream mitogen-activated protein kinase/extracellular signal-regulated kinase(MAPK/ERK)signaling pathway.Collectively,circ_0053943 may promote UM progression by stabilizing EGFR mRNA and activating the MAPK/ERK signaling pathway through the formation of a circ_0053943/IGF2BP3/EGFR RNA-protein ternary complex,thus providing a potential biomarker and therapeutic target for UM.

Repurposing Loperamide as an Anti-Infection Drug for the Treatment of Intracellular Bacterial Pathogens

Infections caused by intracellular bacterial pathogens are difficult to treat since most antibiotics have low cell permeability and undergo rapid degradation within cells.The rapid development and dissemination of antimicrobial–resistant strains have exacerbated this dilemma.With the increasing knowledge of host–pathogen interactions,especially bacterial strategies for survival and proliferation within host cells,host-directed therapy(HDT)has attracted increased interest and has emerged as a promising antiinfection method for treating intracellular infection.Herein,we applied a cell-based screening approach to a US Food and Drug Administration(FDA)-approved drug library to identify compounds that can inhibit the intracellular replication of Salmonella Typhimurium(S.Typhimurium).This screening allowed us to identify the antidiarrheal agent loperamide(LPD)as a potent inhibitor of S.Typhimurium intracellular proliferation.LPD treatment of infected cells markedly promoted the host autophagic response and lysosomal activity.A mechanistic study revealed that the increase in host autophagy and elimination of intracellular bacteria were dependent on the high expression of glycoprotein nonmetastatic melanoma protein B(GPNMB)induced by LPD.In addition,LPD treatment effectively protected against S.Typhimurium infection in Galleria mellonella and mouse models.Thus,our study suggested that LPD may be useful for the treatment of diseases caused by intracellular bacterial pathogens.Moreover,LPD may serve as a promising lead compound for the development of anti-infection drugs based on the HDT strategy.