Oral　squamous　cell　carcinoma　(OSCC)　cells　are　usually　resistant　to　doxorubicin,　resulting　in　limited　application　of　doxorubicin　in　OSCC　treatment.　MicroRNA　(miR)　-221　has　been　reported　to　be　involved　in　the　development　of　OSCC;　however,　it　remains　unclear　if　and　how　miR-221　is　implicated　in　modulating　the　sensitivity　of　OSCC　cells　to　doxorubicin.　In　the　present　study,　reverse　transcription-quantitative　polymerase　chain　reaction　(RT-qPCR)　was　used　to　assess　miR-221　expression　in　OSCC　cells　in　response　to　doxorubicin　treatment.　In　addition,　the　SCC4　and　SCC9　OSCC　cell　lines　were　transfected　with　anti-miR-221　oligonucleotides　and　cell　viability　and　apoptosis　following　doxorubicin　treatment　were　evaluated　using　an　MTT　assay　and　Annexin　V-fluorescein　isothiocyanate/Hoechst　double　staining,　respectively.　The　mRNA　and　protein　expression　levels　of　tissue　inhibitor　of　metalloproteinase-3　(TIMP3)　in　anti-miR-221-transfected　cells　were　assessed　using　RT-qPCR　and　western　blot　analysis,　respectively.　Furthermore,　a　luciferase　reporter　assay　was　performed　to　investigate　whether　TIMP3　may　be　a　direct　target　gene　of　miR-221.　To　explore　the　roles　of　TIMP3　in　miR-221-mediated　cell　responses,　TIMP3　expression　was　silenced　following　transfection　with　TIMP3-targeting　small　interfering　(si)　RNA　in　cells　overexpressing　miR-221,　and　cell　viability　and　apoptosis　in　response　to　doxorubicin　treatment　were　measured.　The　results　of　the　present　study　demonstrated　that　miR-221　expression　was　upregulated　in　SCC4　and　SCC9　cells　following　treatment　with　doxorubicin.　However,　inhibiting　the　doxorubicin-induced　upregulation　of　miR-221　through　transfection　with　anti-miR-221　oligonucleotides　led　to　an　increase　in　the　sensitivity　of　OSCC　cells　to　doxorubicin.　In　addition,　the　results　indicated　that　TIMP3　was　a　direct　target　of　miR-221　in　OSCC　cells,　as　determined　by　a　3＇-untranslated　region　luciferase　reporter　assay.　Co-transfection　of　cells　with　anti-miR-221　oligonucleotides　and　TIMP3-specific　small　interfering　RNA　resulted　in　reduced　sensitivity　to　doxorubicin　compared　with　the　cells　transfected　with　the　miR-221　inhibitor　alone.　In　conclusion,　these　results　indicated　that　OSCC　cells　are　resistant　to　doxorubicin　through　upregulation　of　miR-221,　which　in　turn　downregulates　TIMP3.　Therefore,　silencing　miR-221　or　upregulating　TIMP3　may　be　considered　promising　therapeutic　approaches　to　enhance　the　sensitivity　of　OSCC　to　doxorubicin.