LDL-mediated chemoresistance to Lapatinib involves dysregulation of CYP3A4, SULT1A1, and HER2 signaling in HER2+ breast cancer

LDL-mediated chemoresistance to Lapatinib involves dysregulation of CYP3A4, SULT1A1, and HER2 signaling in HER2+ breast cancer | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article LDL-mediated chemoresistance to Lapatinib involves dysregulation of CYP3A4, SULT1A1, and HER2 signaling in HER2+ breast cancer Victor Garcia-Gonzalez, Ruth Areli García-Villarreal, Octavio Galindo-Hernández, and 7 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8015205/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 9 You are reading this latest preprint version Abstract Breast cancer (BC) remains one of the leading causes of cancer-related death in women worldwide. HER2-positive BC accounts for approximately 15–20% of all cases and is associated with aggressive disease and poor prognosis. Although Lapatinib, a dual tyrosine kinase inhibitor (TKI), is a cornerstone in HER2+ BC therapy, the emergence of chemoresistance severely limits its long-term efficacy, a phenomenon that dyslipidemias may influence. We characterized a Lapatinib-resistant cell model (BT474LapRV2) to explore the impact of low-density lipoproteins (LDL) on chemoresistance mechanisms in HER2+ BC. LDL uptake was evaluated by flow cytometry and confocal microscopy. Functional assays, qPCR, Western blotting, and molecular docking were employed to assess changes in proliferation, apoptosis, and the regulation of drug metabolism and efflux pathways. LDL treatment promoted cell proliferation and resistance to apoptosis in both parental (BT474Par) and resistant BT474LapRV2 cells. This effect was associated with differential modulation of cholesterol-regulating proteins (LDLR, SREBP2), drug-metabolizing enzymes (CYP3A4, SULT1A1), and drug efflux transporters (ABCB1, ABCC1). Notably, LDL selectively upregulated SULT1A1 in resistant cells, suggesting a metabolic shift toward sulfation-mediated inactivation of Lapatinib. Molecular docking confirmed strong binding affinity of Lapatinib and its metabolites to SULT1A1, ABCC1, and ABCB1, supporting their role in drug detoxification and exportation. In parallel, LDL induced reactivation of HER2 expression in resistant cells, enhancing survival signaling. Data demonstrated that LDL facilitates Lapatinib resistance in HER2+ BC by remodeling drug and lipid metabolic pathways, notably through SULT1A1 overexpression and HER2 reactivation. These findings highlight LDL as a metabolic driver of chemoresistance and support the therapeutic potential of targeting lipid metabolism and phase II drug enzymes in resistant HER2+ BC. Health sciences/Diseases/Cancer/Breast cancer Biological sciences/Cancer/Cancer metabolism Biological sciences/Drug discovery/Biomarkers Health sciences/Biomarkers HER2-positive breast cancer Lapatinib resistance low-density lipoproteins (LDL) SULT1A1 CYP3A4 ABC transporters metabolic reprogramming Full Text Additional Declarations There is NO conflict of interest to disclose. Supplementary Files Supplementaryfigures.pdf Supplementary figures Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: revise 03 Feb, 2026 Review # 2 received at journal 29 Dec, 2025 Reviewer # 2 agreed at journal 12 Dec, 2025 Reviewer # 1 agreed at journal 12 Dec, 2025 Reviewers invited by journal 11 Dec, 2025 Submission checks completed at journal 08 Dec, 2025 First submitted to journal 04 Dec, 2025 Unknown event 04 Nov, 2025 Editor assigned by journal 03 Nov, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8015205","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":558777500,"identity":"2e33141c-1e1b-4d1b-9c17-a2e425a19ce3","order_by":0,"name":"Victor Garcia-Gonzalez","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA7klEQVRIiWNgGAWjYNACAwY5fvYGBmYw5wCRWowlew6QpIWBIdHgRgKRWgzOL3724UeBXQLDzTeGnwtqGOT4biSwbubBp+XGM+OZPQbJeYyzc4ylZxwDuvBGAtvNGXi0SM44YMzMYMBczCydYyDN28CQuAGo5cYHvFqOfwZqqU9skzxj/BuopR6sJQGPFn7+HpAthxN7JHjMQLYkGBCyhV+Cp5ixx+C4sQRPWpn1jGMShjPPPGzD6xc2/uObGX78qZazP3548+2CGht5vuPJx27jCzEGCVRnSwAxYwM+DUCXHcAvPwpGwSgYBaOAAQDYL0ySswpwDwAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0002-9421-3730","institution":"Universidad Autonoma de Baja California","correspondingAuthor":true,"prefix":"","firstName":"Victor","middleName":"","lastName":"Garcia-Gonzalez","suffix":""},{"id":558777501,"identity":"1d9432c2-1417-460b-a052-bfd31115cc05","order_by":1,"name":"Ruth Areli García-Villarreal","email":"","orcid":"https://orcid.org/0009-0001-0268-3437","institution":"Universidad Autonoma de Baja California","correspondingAuthor":false,"prefix":"","firstName":"Ruth","middleName":"Areli","lastName":"García-Villarreal","suffix":""},{"id":558777502,"identity":"32bd602c-1355-4dda-8988-5e3bbf04efc0","order_by":2,"name":"Octavio Galindo-Hernández","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Octavio","middleName":"","lastName":"Galindo-Hernández","suffix":""},{"id":558777503,"identity":"1cc31ea3-4f2d-41fe-8396-45b6d37c1d1d","order_by":3,"name":"Raúl Díaz-Molina","email":"","orcid":"","institution":"Universidad Autonoma de Baja California","correspondingAuthor":false,"prefix":"","firstName":"Raúl","middleName":"","lastName":"Díaz-Molina","suffix":""},{"id":558777504,"identity":"0b5f9684-1870-4629-90e2-4fc64b30acee","order_by":4,"name":"José Luis Vique-Sánchez","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"José","middleName":"Luis","lastName":"Vique-Sánchez","suffix":""},{"id":558777506,"identity":"720a6456-423e-49c5-a894-5d548d5317e1","order_by":5,"name":"Nicolás Serafín-Higuera","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Nicolás","middleName":"","lastName":"Serafín-Higuera","suffix":""},{"id":558777507,"identity":"abd04157-352b-48c1-a02b-7fa9c8462bc1","order_by":6,"name":"Manuel Alatorre-Meda","email":"","orcid":"","institution":"Universidad Autonoma de Baja California","correspondingAuthor":false,"prefix":"","firstName":"Manuel","middleName":"","lastName":"Alatorre-Meda","suffix":""},{"id":558777508,"identity":"055e9fb8-7561-4588-98d2-1dee56203a13","order_by":7,"name":"Eustolia Rodríguez-Velázquez","email":"","orcid":"","institution":"Universidad Autonoma de Baja California","correspondingAuthor":false,"prefix":"","firstName":"Eustolia","middleName":"","lastName":"Rodríguez-Velázquez","suffix":""},{"id":558777509,"identity":"dd9cf4da-c1f0-43db-b195-181a97f70da3","order_by":8,"name":"Angel Pulido-Capiz","email":"","orcid":"","institution":"Universidad Autonoma de Baja California","correspondingAuthor":false,"prefix":"","firstName":"Angel","middleName":"","lastName":"Pulido-Capiz","suffix":""},{"id":558777510,"identity":"ad6ce376-7341-41a1-9029-17f95cd94e2c","order_by":9,"name":"Brenda Chimal-Vega","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Brenda","middleName":"","lastName":"Chimal-Vega","suffix":""}],"badges":[],"createdAt":"2025-11-03 06:00:23","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8015205/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8015205/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":98466288,"identity":"30d152a4-c971-4bba-9e9c-ff964eee7154","added_by":"auto","created_at":"2025-12-17 23:16:36","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":2383483,"visible":true,"origin":"","legend":"","description":"","filename":"Fig.3.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8015205/v1/29384b2cb05e963ff508d043.pdf"},{"id":98623259,"identity":"75b44e99-b7f2-4852-9ac5-16d0c759d6bb","added_by":"auto","created_at":"2025-12-19 17:05:29","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":248334,"visible":true,"origin":"","legend":"","description":"","filename":"Fig.4.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8015205/v1/8c9c7cf4955398e21c35ac7a.pdf"},{"id":98623319,"identity":"2cea8b90-b6be-485e-858b-46bc850f85ec","added_by":"auto","created_at":"2025-12-19 17:05:48","extension":"pdf","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":1944182,"visible":true,"origin":"","legend":"","description":"","filename":"LDLmediatedchemoresistance04Dic25.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8015205/v1/b655f1f2df408062970b016e.pdf"},{"id":98623024,"identity":"c0e3c875-f229-4026-8a8f-427dbab2f188","added_by":"auto","created_at":"2025-12-19 17:04:07","extension":"pdf","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":2115183,"visible":true,"origin":"","legend":"","description":"","filename":"Fig.6.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8015205/v1/fcdcaa7bf886990668d52045.pdf"},{"id":98466286,"identity":"9c2f49fb-17b3-446f-8ffe-32d92db6d35a","added_by":"auto","created_at":"2025-12-17 23:16:36","extension":"pdf","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":2174788,"visible":true,"origin":"","legend":"","description":"","filename":"Fig.1.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8015205/v1/c9772edbbfc62e65bfabe00c.pdf"},{"id":98466293,"identity":"3e7922cd-8559-4809-9c81-de019eced7e1","added_by":"auto","created_at":"2025-12-17 23:16:36","extension":"pdf","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":2815514,"visible":true,"origin":"","legend":"","description":"","filename":"Fig.2.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8015205/v1/67c86d22ebbbb2bd75b30abe.pdf"},{"id":98623205,"identity":"481cfc6b-2937-4fca-b4d8-68a50a243447","added_by":"auto","created_at":"2025-12-19 17:05:15","extension":"pdf","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":1168459,"visible":true,"origin":"","legend":"","description":"","filename":"Fig.5.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8015205/v1/2d38fc4b9ba61b842ef03327.pdf"},{"id":98466295,"identity":"59e37722-009d-48c9-a57a-64dcecb1144f","added_by":"auto","created_at":"2025-12-17 23:16:36","extension":"pdf","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":1813072,"visible":true,"origin":"","legend":"","description":"","filename":"Fig.7.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8015205/v1/a2bf186d47eba6cffc78054c.pdf"},{"id":98623575,"identity":"d728f965-d132-41c0-9e2c-b9efe9246c98","added_by":"auto","created_at":"2025-12-19 17:06:59","extension":"json","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":11791,"visible":true,"origin":"","legend":"","description":"","filename":"CGT251005.json","url":"https://assets-eu.researchsquare.com/files/rs-8015205/v1/e9af1d17638c96cc81db1910.json"},{"id":98623254,"identity":"89279230-75c8-40a3-95af-6591c33e771d","added_by":"auto","created_at":"2025-12-19 17:05:28","extension":"pdf","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":564274,"visible":true,"origin":"","legend":"","description":"","filename":"Supplementaryfigures.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8015205/v1/56018acceb6f974b7fd41347.pdf"},{"id":98631318,"identity":"b99701fe-66de-42f6-b647-90b7d308ea3a","added_by":"auto","created_at":"2025-12-19 17:19:49","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1513390,"visible":true,"origin":"","legend":"Article File","description":"","filename":"LDLmediatedchemoresistance04Dic25.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8015205/v1_covered_eef532a3-115b-4313-8891-f9079650ec1e.pdf"},{"id":98466285,"identity":"8fe74e6f-a7c9-47e6-9d05-6cdf5e981c61","added_by":"auto","created_at":"2025-12-17 23:16:36","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":564274,"visible":true,"origin":"","legend":"Supplementary figures","description":"","filename":"Supplementaryfigures.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8015205/v1/92da0c436e592c36106cdc64.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e conflict of interest to disclose.","formattedTitle":"LDL-mediated chemoresistance to Lapatinib involves dysregulation of CYP3A4, SULT1A1, and HER2 signaling in HER2+ breast cancer","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"cancer-gene-therapy","isNatureJournal":false,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"cgt","sideBox":"Learn more about [Cancer Gene Therapy](http://www.nature.com/cgt/)","snPcode":"41417","submissionUrl":"https://mts-cgt.nature.com/cgi-bin/main.plex","title":"Cancer Gene Therapy","twitterHandle":"@cgtnature","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"HER2-positive breast cancer, Lapatinib resistance, low-density lipoproteins (LDL), SULT1A1, CYP3A4, ABC transporters, metabolic reprogramming","lastPublishedDoi":"10.21203/rs.3.rs-8015205/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8015205/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"Breast cancer (BC) remains one of the leading causes of cancer-related death in women worldwide. HER2-positive BC accounts for approximately 15–20% of all cases and is associated with aggressive disease and poor prognosis. Although Lapatinib, a dual tyrosine kinase inhibitor (TKI), is a cornerstone in HER2+ BC therapy, the emergence of chemoresistance severely limits its long-term efficacy, a phenomenon that dyslipidemias may influence. We characterized a Lapatinib-resistant cell model (BT474LapRV2) to explore the impact of low-density lipoproteins (LDL) on chemoresistance mechanisms in HER2+ BC. LDL uptake was evaluated by flow cytometry and confocal microscopy. Functional assays, qPCR, Western blotting, and molecular docking were employed to assess changes in proliferation, apoptosis, and the regulation of drug metabolism and efflux pathways. LDL treatment promoted cell proliferation and resistance to apoptosis in both parental (BT474Par) and resistant BT474LapRV2 cells. This effect was associated with differential modulation of cholesterol-regulating proteins (LDLR, SREBP2), drug-metabolizing enzymes (CYP3A4, SULT1A1), and drug efflux transporters (ABCB1, ABCC1). Notably, LDL selectively upregulated SULT1A1 in resistant cells, suggesting a metabolic shift toward sulfation-mediated inactivation of Lapatinib. Molecular docking confirmed strong binding affinity of Lapatinib and its metabolites to SULT1A1, ABCC1, and ABCB1, supporting their role in drug detoxification and exportation. In parallel, LDL induced reactivation of HER2 expression in resistant cells, enhancing survival signaling. Data demonstrated that LDL facilitates Lapatinib resistance in HER2+ BC by remodeling drug and lipid metabolic pathways, notably through SULT1A1 overexpression and HER2 reactivation. These findings highlight LDL as a metabolic driver of chemoresistance and support the therapeutic potential of targeting lipid metabolism and phase II drug enzymes in resistant HER2+ BC.","manuscriptTitle":"LDL-mediated chemoresistance to Lapatinib involves dysregulation of CYP3A4, SULT1A1, and HER2 signaling in HER2+ breast cancer","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-12-17 23:16:32","doi":"10.21203/rs.3.rs-8015205/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"revise","date":"2026-02-03T09:56:01+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"This content is not available.","date":"2025-12-29T19:24:50+00:00","index":2,"fulltext":"This content is not available."},{"type":"reviewerAgreed","content":"This content is not available.","date":"2025-12-13T03:57:21+00:00","index":2,"fulltext":"This content is not available."},{"type":"reviewerAgreed","content":"This content is not available.","date":"2025-12-12T15:12:36+00:00","index":1,"fulltext":"This content is not available."},{"type":"reviewersInvited","content":"","date":"2025-12-11T11:04:42+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-12-08T12:46:24+00:00","index":"","fulltext":""},{"type":"submitted","content":"Cancer Gene Therapy","date":"2025-12-05T02:48:20+00:00","index":"","fulltext":""},{"type":"checksFailed","content":"","date":"2025-11-04T14:11:22+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-11-03T05:55:52+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"cancer-gene-therapy","isNatureJournal":false,"hasQc":false,"allowDirectSubmit":false,"externalIdentity":"cgt","sideBox":"Learn more about [Cancer Gene Therapy](http://www.nature.com/cgt/)","snPcode":"41417","submissionUrl":"https://mts-cgt.nature.com/cgi-bin/main.plex","title":"Cancer Gene Therapy","twitterHandle":"@cgtnature","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"ejp","reportingPortfolio":"Nature AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"c2bb517a-11ae-4759-8dbf-d61d9d2456fb","owner":[],"postedDate":"December 17th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"in-revision","subjectAreas":[{"id":59483737,"name":"Health sciences/Diseases/Cancer/Breast cancer"},{"id":59483738,"name":"Biological sciences/Cancer/Cancer metabolism"},{"id":59483739,"name":"Biological sciences/Drug discovery/Biomarkers"},{"id":59483740,"name":"Health sciences/Biomarkers"}],"tags":[],"updatedAt":"2026-02-03T10:01:19+00:00","versionOfRecord":[],"versionCreatedAt":"2025-12-17 23:16:32","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8015205","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8015205","identity":"rs-8015205","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}