影响口腔鳞状细胞癌患者预后的临床病理因素分析

目的：研究影响口腔鳞状细胞癌（Oral squamous cellcar cinoma,OSCC）术后患者预后的临床病理因素。方法：回顾性研究55例手术治疗的原发口腔鳞状细胞癌患者与预后相关的因素：年龄、性别、发病部位、颈部淋巴结转移情况、肿瘤细胞分化程度等。结果：平均发病年龄为57.35±12.02岁,牙龈鳞癌的复发转移率最高（45.5%）,舌部第二（44%）,颊部第三（37.5%）,唇癌预后最好（0.0%）。术前颈部淋巴结转移情况、肿瘤细胞分化程度与预后有关。肿瘤细胞的分化程度与术前淋巴结转移无显著相关性。术前有颈部淋巴结转移合并中低分化与预后差相关。结论：口腔鳞状细胞癌的预后与发病部位无显著相关性。肿瘤中低分化及术前有淋巴结转移者易出现术后复发转移。     

影响口腔鳞状细胞癌患者预后的临床病理因素分析

目的:研究影响口腔鳞状细胞癌(Oral squamous cellcar cinoma,OSCC)术后患者预后的临床病理因素。方法:回顾性研究55例手术治疗的原发口腔鳞状细胞癌患者与预后相关的因素:年龄、性别、发病部位、颈部淋巴结转移情况、肿瘤细胞分化程度等。结果:平均发病年龄为57.35±12.02岁,牙龈鳞癌的复发转移率最高(45.5%),舌部第二(44%),颊部第三(37.5%),唇癌预后最好(0.0%)。术前颈部淋巴结转移情况、肿瘤细胞分化程度与预后有关。肿瘤细胞的分化程度与术前淋巴结转移无显著相关性。术前有颈部淋巴结转移合并中低分化与预后差相关。结论:口腔鳞状细胞癌的预后与发病部位无显著相关性。肿瘤中低分化及术前有淋巴结转移者易出现术后复发转移。     

CD9在口腔鳞状细胞癌中的表达水平及其临床意义

目的:口腔鳞状细胞癌是一类极易发生局部侵袭和淋巴结转移的恶性肿瘤,CD9蛋白在多种肿瘤的发生发展及侵袭转移过程中起到重要作用,本研究旨在分析CD9蛋白在口腔鳞状细胞癌中的表达水平及其临床意义。方法:收集我院诊断明确的口腔鳞癌肿瘤患者石蜡标本合计80例,通过免疫组化手段对CD9蛋白表达水平进行评价,并根据CD9蛋白的表达水平分组,分析患者的临床病理学特征与CD9蛋白的关系。结果:CD9在正常组织和癌旁组织正常表达,在肿瘤组织中表达率低,其表达水平和口腔鳞癌的分化程度,淋巴结转移及最终分期有相关性(P0.05)。结论:本研究结果揭示,CD9在口腔鳞状细胞癌的发生发展中起到重要作用,CD9蛋白水平的低表达或不表达可能预测着肿瘤具有更明显的恶性生物学行为,并可能成为口腔鳞状细胞癌预后的生物学指标及基因治疗的新靶点。     

VEGF在口腔鳞状细胞癌中的表达及其临床意义

目的:研究血管内皮生长因子(Vascular endothelial growth factor,VEGF)在口腔鳞状细胞癌中的表达及其临床意义.方法:免疫组化EnVisionTM法检测VEGF在57例手术治疗的原发性OSCC(口腔鳞状细胞癌)中的表迭.结果:①VEGF在OSCC中的阳性表达率为40.35%.②VEGF在不同发病部位组的表达:牙龈癌>舌癌>颊癌>唇癌,组间无统计学差异(P>0.05).③VEOF在不同病理分级组、不同预后组、不同年龄组、不同性别组的表达无显著性差异(P>0.05);淋巴结转移组的表达显著高于无转移组(P<0.05).结论:虽然VEGF的高表达可能在淋巴结转移中起一定的作用,但还不能作为预测口腔鳞状细胞癌临床生物学行为及预后的可靠指标.     

口腔鳞状细胞癌中VEGF、Bcl-2的表达及意义

目的研究血管内皮细胞生长因子VEGF、Bcl-2在口腔鳞状细胞癌(OSCC)中的表达及意义。方法应用免疫组化SP法检测。结果在OSCC不同分化及TNM分期病例中VEGF阳性表达率无显著差异,但Ⅳ期VEGF阳性表达级别比Ⅰ期病例有显著增高。颈淋巴结转移组的VEGF比无颈淋巴结转移组阳性率高(P<0.05)。OSCC高分化组中Bcl-2的表达率比中低分化组明显低(P<0.05)。VEGF阳性级别越高的病例组,Bc-l2的表达率越高。结论在口腔鳞癌中VEGF、Bcl-2的表达有显著的正相关关系。     

VEGF-C 在口腔鳞状细胞癌中的表达及其意义

目的:检测血管内皮生长因子-C(VEGF-C)在口腔鳞状细胞癌(鳞癌)和癌旁组织中的表达情况,探讨VEGF-C在口腔鳞癌的增殖、浸润和淋巴转移中的作用。方法:采用免疫组化方法检测60例口腔鳞癌病人癌组织和癌旁组织中VEGF-C的表达,应用图像分析系统进行分析,用Spearman相关分析研究其与病变部位、肿瘤大小、病理分级、临床分期及颈淋巴结转移之间的关系。结果:口腔鳞癌组织VEGF-C的表达明显高于癌旁组织(u=7.747,P<0.01),其表达强度与临床分期及淋巴结转移密切相关(r=0.564、0.706,P<0.05),与病变部位、大小、病理分级无关。结论:口腔鳞癌细胞分泌VEGF-C诱导癌周淋巴管增生扩张是发生区域淋巴结转移的重要因素之一,VEGF-C有望作为早期临床判断和预测颈淋巴结转移的指标之一。     

单细胞测序技术在口腔鳞状细胞癌研究中的应用

单细胞测序技术是在单细胞水平上对目标细胞遗传信息进行测序。该技术已应用于众多医学领域,在研究肿瘤细胞的异质性、肿瘤的发生、发展及耐药性等方面具有独特的优势。口腔鳞状细胞癌是高侵袭性头颈部癌之一,其局部复发风险高,存活率低于一般头颈癌组,以手术治疗为主,放射和化学治疗为辅。然而,多数口腔鳞状细胞癌患者预后不佳,存在局部复发和高转移。本文总结了单细胞测序技术的发展及其在口腔鳞状细胞癌研究中的应用,旨在为口腔鳞状细胞癌的精准诊治提供新的见解。     

MMP14单克隆抗体对口腔鳞状细胞癌增殖、凋亡的影响

[目的]探究MMP14单克隆抗体对口腔鳞状细胞癌细胞增殖、凋亡的影响。[方法]构建MMP14敲低(Kd-TCa8113)、过表达(Kd-TCa8113)细胞株,与野生型TCa8113(Wt-TCa8113)对比,考察MMP14对TCa8113细胞增殖、凋亡的影响。用不同浓度的MMP14单克隆抗体与TCa8113共培养,以探讨MMP14单克隆抗体对TCa8113细胞增殖、凋亡的影响。[结果]以Wt-TCa8113为对照组,Kd-TCa8113组、Kd-TCa8113组的细胞培养48 h的增殖率分别为74.55%、114.79%,P均<0.05。流式细胞术结果显示,Wt-TCa8113、Kd-TCa8113和Oe-TCa8113培养48 h后的细胞凋亡率分别为3.47%±0.36%、33.68%±7.33%和1.60%±0.22%,P均<0.05。用50μg/mL、100μg/mL和200μg/mL浓度的抗体处理TCa8113细胞24 h后,以PBS处理组为对照,细胞增殖率分别为93.52%、90.75%和87.61%,P均<0.05。流式细胞术结果显示,PBS组和上述抗...     

组胺H4受体在口腔上皮异常增生和口腔舌鳞状细胞癌中的表达

组胺(Histamine)及组胺H4受体H4R (Histamine H4 receptor)在癌症发生发展中具有重要作用。目前,H4R在口腔上皮异常增生(oral epithelial dysplasia, OED)和口腔舌鳞状细胞癌(oral tongue squamous cell carcinoma, OTSCC)中的作用尚不清楚。本研究采用免疫组化法检测OED、OTSCC和健康口腔粘膜组织中H4R的表达情况。并分析人口腔角质细胞系(HOK)和人舌鳞状细胞癌HSC-3细胞系(HSC-3)中H4R及其合成酶L-组氨酸脱羧酶(L-histidine decarboxylase, HDC)的表达。应用肥大细胞释放物(MCR)刺激HOK细胞。研究发现,H4R在OED和OTSCC组织中显著下调(p0.05);H4R和HDC的m RNA表达在HSC-3细胞中下调(p0.05);肥大细胞释放物(MCR)刺激可下调HOK细胞中H4R和HDC的表达(p0.05)。本研究得出初步结论,H4R与口腔癌发生发展密切相关,癌症严重程度越高,H4R表达水平越低。口腔癌症组织中H4R的低表达可能通过肥大细胞释放物进行调节。     

CXXC4、EZH2在口腔鳞状细胞癌中表达及临床意义

目的:探讨口腔鳞状细胞癌(Oral Squamous Cell Carcinoma,OSCC)中CXXC指蛋白4(CXXC finger protein 4,CXXC4)与Zeste基因增强子同源物2(Enhancer of zeste homolog 2,EZH2)的表达、相关性及与临床病理特征之间的关系,为OSCC的早期诊断、治疗、判断预后及预防等提供参考依据。方法:采用免疫组织化学S-P法检测CXXC4蛋白及EZH2蛋白在60例口腔鳞状细胞癌组织及20例非肿瘤患者正常口腔黏膜组织中的表达情况,分析二者与口腔鳞状细胞癌临床病理特征的相关性。结果:口腔鳞状细胞癌组织中CXXC4蛋白的表达率为35.0%(21/60),明显低于正常口腔黏膜组织的60.0%(12/20)(P0.05);口腔鳞状细胞癌中EZH2蛋白的表达率为70.0%(42/60),高于正常口腔黏膜组织的25%(5/20)(P0.05)。CXXC4蛋白与EZH2蛋白的表达与口腔鳞状细胞癌的病理分化程度、TNM分期及淋巴结转移等密切相关(P0.05),而与年龄、性别及肿瘤直径大小等无关。CXXC4蛋白与EZH2蛋白在OSCC中表达呈负相关(r=-0.511,P0.001)。结论:CXXC4蛋白的表达下调或缺失以及EZH2蛋白的表达上调或过表达与口腔鳞状细胞癌的发生、发展及侵袭转移有关,可能作为口腔鳞状细胞癌预后预测的参考指标。     

Cancer stem cell-like cells from a single cell of oral squamous carcinoma cell lines

Resistance of oral squamous cell carcinomas (OSCC) to conventional chemotherapy or radiation therapy might be due to cancer stem cells (CSCs). The development of novel anticancer drugs requires a simple method for the enrichment of CSCs. CSCs can be enriched from OSCC cell lines, for example, after cultivation in serum-free cell culture medium (SFM). In our study, we analyzed four OSCC cell lines for the presence of CSCs. CSC-like cells could not be enriched with SFM. However, cell lines obtained from holoclone colonies showed CSC-like properties such as a reduced rate of cell proliferation and a reduced sensitivity to Paclitaxel in comparison to cells from the parental lineage. Moreover, these cell lines differentially expressed the CSC-marker CD133, which is also upregulated in OSCC tissues. Interestingly, CD133⁺ cells in OSCC tissues expressed little to no Ki67, the cell proliferation marker that also indicates reduced drug sensitivity. Our study shows a method for the isolation of CSC-like cell lines from OSCC cell lines. These CSC-like cell lines could be new targets for the development of anticancer drugs under in vitro conditions.     

Porphyromonas gingivalis in oral squamous cell carcinoma: a review

Oral cancer contributes significantly to the global cancer burden. Oral bacteria play an important role in the spread of oral cancer, according to mounting evidence. The most proven instance is the carcinogenic implications of Porphyromonas gingivalis, a key pathogen in chronic periodontitis. It is imperative to understand the pathogenesis of P. gingivalis in OSCC. This review aims to gather and assess scientific shreds of evidence on the involvement of P. gingivalis in the molecular mechanism of oral squamous cell carcinoma.     

口腔鳞状细胞癌患者外周血Naa10及淋巴细胞免疫分型的特点及临床意义

目的探讨口腔鳞状细胞癌（OSCC）患者外周血N-α-乙酰基转移酶10 （Naa10）及淋巴细胞免疫分型的特点,并分析其临床意义。 方法选取97例OSCC患者及50名健康体检者,分别纳入患者组、对照组。检测两组受试者外周血Naa10、淋巴细胞免疫分型,并比较不同TNM分期、不同淋巴结转移状态患者外周血Naa10、淋巴细胞免疫分型的差异,总结其特点与临床意义。不同性别人数采用χ²检验,计量资料行正态性检验,满足正态性且组间方差相等则采用t检验,不满足正态性则采用非参数Wilcoxon秩和检验,相关性分析采用Pearson法。 结果患者组血清Naa10为（62.91±17.15）pg/ml,高于对照组的（38.82±9.04）pg/ml,差异有统计学意义（t?= 9.280,P?< 0.05）。患者组CD3⁺、CD4⁺、CD4⁺/CD8⁺、NK细胞百分比分别为（71.63±9.11）﹪、（34.34±4.26）﹪、（1.03±0.28）、（14.23±4.61）﹪,低于对照组的（76.25±2.87）﹪、（45.41±7.08）﹪、（1.77± 0.39）、（19.96±5.13）﹪,CD8⁺、B淋巴细胞百分比分别为（14.23±4.61）﹪、（14.91±3.29）﹪,高于后者的（19.96±5.13）﹪、（9.11±2.60）﹪,差异有统计学意义（P?< 0.05）。TNM分期Ⅰ~Ⅱ期患者42例,其血清Naa10为（64.08±15.26）?pg/?ml,与Ⅲ~Ⅳ期患者的（61.71±13.15）pg/ml比较,差异无统计学意义（t?= 0.820,P?> 0.05）。淋巴结转移者34例,其血清Naa10为（65.15±14.07）pg/ml,与无淋巴结转移者的（61.45±12.66）?pg/?ml比较,差异无统计学意义（t?= 1.321,P?> 0.05）。Ⅰ~Ⅱ期患者CD3⁺、CD4⁺、CD4⁺/CD8⁺、NK细胞百分比低于Ⅲ~Ⅳ期患者,其CD8⁺、B淋巴细胞百分比高于后者,差异有统计学意义（P?< 0.05）。Pearson相关性分析示,外周血Naa10与CD3⁺ （-0.631）、CD4⁺ （-0.529）、CD4⁺/CD8⁺ （-0.587）、NK细胞百分比（-0.603）呈负相关,与CD8⁺ （0.558）、B淋巴细胞百分比（0.670）呈正相关（P?< 0.05）。 结论OSCC患者外周血Naa10明显升高但与TNM分期、淋巴结转移无关;其淋巴细胞免疫分型存在明显改变,且TNM分期的上升、淋巴结转移的发生伴随着CD3⁺、CD4⁺、CD4⁺/?CD8⁺、NK细胞百分比的下降,以及CD8⁺、B淋巴细胞百分比的上升。     

Expression of Snail is associated with myofibroblast phenotype development in oral squamous cell carcinoma

Snail is a regulator of epithelial–mesenchymal transition (EMT) and considered crucial to carcinoma metastasis, myofibroblast transdifferentiation, and fibroblast activation. To investigate the role of Snail in oral squamous cell carcinoma (OSCC), its immunohistochemical expression was analysed in 129 OSCC samples and correlated to nodal metastasis, histological grade, E-cadherin, and alpha smooth-muscle-actin (αSMA). The results were compared to findings in 23 basal cell carcinomas (BCC). Additionally, the influence of TGFβ1 and EGF on Snail, E-cadherin, vimentin, and αSMA expression was analysed in two OSCC cell lines. As a result, Snail-positive cells were mainly found in the stroma of the OSCC invasive front without statistically significant correlation to histological grade or nodal metastasis. Snail was co-localised to αSMA but not to E-cadherin or cytokeratin and showed a significant correlation to the loss of membranous E-cadherin. All BCCs were Snail negative. In OSCC culture, the growth-factor-mediated EMT-like phenomenon was accompanied by αSMA down-regulation. In summary, Snail expression in OSCC is a stromal phenomenon associated with the myofibroblast phenotype and not related to growth-factor-mediated transdifferentiation of the carcinoma cells themselves. Consequently, Snail immunohistochemistry cannot contribute to the prediction of the metastatic potential. Furthermore, stromal Snail expression is suggested to be the result of mutual paracrine interaction of fibro-/myofibroblasts and dedifferentiated carcinoma cells leading to the generation of a special type of carcinoma-associated fibroblasts. M. Franz and K. Spiegel have contributed equally to the study.     

Anti-tumor effect of carrimycin on oral squamous cell carcinoma cells in vitro and in vivo

Purpose: Carrimycin is a newly synthesized macrolide antibiotic with good antibacterial effect. Exploratory experiments found its function in regulating cell physiology, proliferation and immunity, suggesting its potential anti-tumor capacity. The aim of this study is to investigate the anti-tumor effect of carrimycin against human oral squamous cell carcinoma cells in vitro and in vivo.Methods: Human oral squamous cell carcinoma cells (HN30/HN6/Cal27/HB96 cell lines) were treated with gradient concentration of carrimycin. Cell proliferation, colony formation and migration ability were analyzed. Cell cycle and apoptosis were assessed by flow cytometry. The effect of carrimycin on OSCC in vivo was investigated in tumor xenograft models. Immunohistochemistry, western blot assay and TUNEL assays of tissue samples from xenografts were performed. The key proteins in PI3K/AKT/mTOR pathway and MAPK pathway were examined by western blot.Results: As the concentration of carrimycin increased, the proliferation, colony formation and migration ability of OSCC cells were inhibited. After treating with carrimycin, cell cycle was arrested in G0/G1 phase and cell apoptosis was promoted. The tumor growth of xenografts was significantly suppressed. Furthermore, the expression of p-PI3K, p-AKT, p-mTOR, p-S6K, p-4EBP1, p-ERK and p-p38 were down-regulated in vitro and in vivo.Conclusions: Carrimycin can inhibit the biological activities of OSCC cells in vitro and in vivo, and regulate the PI3K/AKT/mTOR and MAPK pathways.     

Toll-like receptor 2 activation implicated in oral squamous cell carcinoma development

Recent studies have revealed that Toll-like receptors (TLRs) are highly expressed and activated in many types of cancer. Physiologically, TLR2 recognizes bacteria and other microorganisms in the oral cavity; however, the role of TLR2 in oral squamous cell carcinoma (OSCC) is unclear. In this study, we demonstrated that TLR2 is highly expressed in OSCC in comparison with adjacent non-malignant tissue. TLR2 was also expressed in OSCC-derived cell lines, and its expression was activated by ligands derived from bacteria and mycoplasma. Furthermore, to elucidate the mechanism of OSCC progression via TLR2 signal transduction, we focused on microRNAs (miRNAs) that are induced by TLR2 activation. Interestingly, ligand activation of TLR2 induced the expression of miR-146a and we found that downregulation of caspase recruitment domain–containing protein 10 (CARD10) mRNA in OSCC-derived cell lines. Moreover, knockdown of CARD10 induced resistance to cisplatin-induced apoptosis in OSCC cells. These findings suggest that the activation of TLR2 by bacterial components can enhance the progression of OSCC and may be implicated in acquired resistance to cisplatin-induced apoptosis through regulation of the miR-146a pathway.     

Ubiquitin-specific protease 14 regulates cell proliferation and apoptosis in oral squamous cell carcinoma

Ubiquitin-specific protease 14, a deubiquitinating enzyme, has been implicated in the tumorigenesis and progression of several cancers, but its role in oral squamous cell carcinoma remains to be elucidated. The aim of this study was to explore the expression pattern and roles of Ubiquitin-specific protease 14 in the occurrence and development of oral squamous cell carcinoma. Interestingly, Ubiquitin-specific protease 14 was overexpressed in oral cancer tissues and cell lines at both mRNA and protein levels. b-AP15, a specific inhibitor of Ubiquitin-specific protease 14, significantly inhibited the growth of cancer cells and increased cell apoptosis in a dose-dependent manner. Moreover, knockdown of Ubiquitin-specific protease 14 by shRNA significantly inhibited the proliferation and migration of cancer cells in vitro. Finally, using a xenograft mouse model of oral squamous cell carcinoma, knockdown of Ubiquitin-specific protease 14 markedly inhibited tumor growth and triggered the cancer cell apoptosis in vivo, supporting previous results. In conclusion, for the first time we have demonstrated the expression pattern of Ubiquitin-specific protease 14 in oral squamous cell carcinoma and verified a relationship with tumor growth and metastasis. These results may highlight new therapeutic strategies for tumor treatment, application of Ubiquitin-specific protease 14 selective inhibitor, such as b-AP15, or knockdown by shRNA. Collectively, Ubiquitin-specific protease 14 could be a potential therapeutic target for oral squamous cell carcinoma patients.     

CMTM5 exhibits tumor suppressor activity through promoter methylation in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is one of the most common types of malignancies in the head and neck region. CKLF-like MARVEL transmembrane domain-containing member 5 (CMTM5) has been recently implicated as a tumor suppressor gene in several cancer types. Herein, we examined the expression and function of CMTM5 in oral squamous cell carcinoma. CMTM5 was down-regulated in oral squamous cell lines and tumor samples from patients with promoter methylation. Treatment with the demethylating agent 5-aza-2′-deoxycytidine restored CMTM5 expression. In the OSCC cell lines CAL27 and GNM, the ectopic expression of CMTM5-v1 strongly inhibited cell proliferation and migration and induced apoptosis. In addition, CMTM5-v1 inhibited tumor formation in vivo. Therefore, CMTM5 might act as a putative tumor suppressor gene through promoter methylation in oral squamous cell carcinoma.     

Ubiquitin-specific protease 14 promotes radio-resistance and suppresses autophagy in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is a common malignant tumor in the world. Radiotherapy is one of the standard therapies for patients with OSCC, but its clinical efficiency is limited due to radioresistance. In this study, we identified a mechanism of such resistance regulated by Ubiquitin-specific protease 14 (USP14). USP14 expression was significantly increased in clinical OSCC tissue samples and cell lines, and OSCC patients with high USP14 expression predicted poor overall survival rate. Additionally, a negative correlation between USP14 and LC3B was observed in patients with OSCC. We then found that irradiation (IR)-reduced cell survival of OSCC cells lines was further decreased when USP14 was knocked down. However, USP14 over-expression significantly promoted the cell viability of OSCC cells after IR treatment. Colony formation analysis confirmed thatafter IR treatment,USP14 knockdown markedly decreased the proliferation of OSCC cells, but over-expressing USP14 significantly up-regulated the proliferative activity of OSCC cells. Furthermore, DNA damage caused by IR was enhanced by USP14 knockdown, while been suppressed in OSCC cells with USP14 over-expression. Additionally, IR-inducedapoptosis was further promoted by USP14 knockdown in OSCC cells, which was, however, significantly abolished by USP14 over-expression.Moreover, our in vivo studies showed that IR-reduced tumor growth and tumor weight were further enhanced by USP14 knockdown in OSCC tumor-bearing nude mice. Finally, we found that USP14 knockdown could promote IR-induced autophagy by increasing LC3BII and γH2AX expression levels in IR-treated OSCC cells. However, this event was markedly abolished by ATG5 knockdown, subsequently restoring the cell proliferation in IR-incubated OSCC cells.Finally, we found that USP14-mediated apoptosis was autophagy-dependent in IR-treated OSCC cells. Taken together, these findings suggested that suppressing USP14 could alleviateradioresistancein OSCC both in vitro and in vivo by inducing apoptosis and autophagy, and thus could be served as a promising therapeutic strategy for OSCC treatment.     

Cytotoxic T cell responses to Streptococcus are associated with improved prognosis of oral squamous cell carcinoma

Several species of Streptococcus, such as S. salivarius, S. mitis, and S. anginosus, are found to extensively colonize the oral cavity and the upper respiratory tract, and have been shown to increase in patients with oral squamous cell carcinoma (OSCC). Accumulating evidence have revealed that commensal bacteria are involved in antitumor immunity via T cell-mediated mechanisms, but the role of Streptococcus enrichment in OSCC is yet unclear. In this study, we stimulated peripheral blood mononuclear cells from non-cancer controls (NCs) and OSCC patients with S. salivarius, S. mitis, and S. anginosus. We observed that compared to NC subjects, OSCC patients at earlier stages had higher frequencies of granzyme B-expressing CD8 T cells for all Streptococcus species tested, while OSCC patients at more advanced stages had higher frequencies of granzyme B-expressing CD8 T cells for S. anginosus but not other Streptococcus species. In OSCC patients, the Streptococcus-reactive CD8 T cells presented significantly lower levels of PD-1 and TIM-3 expression than Streptococcus-nonreactive CD8 T cells. The clinical outcomes of OSCC patients in our cohort were tracked for 24 months after the resection of the primary tumor. In patients that did not present tumor recurrence, the frequencies of S. salivarius-reactive and S. mitis-reactive CD8 T cells were significantly higher than that in patients that developed recurrent tumor. Furthermore, in patients with tumor recurrence, the duration between primary tumor resection and tumor recurrence was positively associated with the frequencies of S. salivarius-reactive and S. anginosus-reactive CD8 T cells. Together, we demonstrated that Streptococcus-reactive CD8 T cell responses might contribute to antitumor immunity in OSCC patients.