Novel Therapeutic Strategies for Malignant Salivary Gland Tumors: Lessons Learned from Breast Cancer

Malignant salivary gland tumors (MSGTs) account for 2–6% of all head and neck cancers. Despite the rarity, MSGTs have been of great interest due to a wide variety of pathological features and high metastasis rates resulting in poor prognosis. Surgical resection followed by radiation therapy represents the main treatment of this malignancy. Adjuvant therapy is reserved for the management of local recurrence, no longer amenable to additional local therapy, and for metastasis. Based on the studies from other types of tumors, particularly breast cancer, the expression and function of sex steroid hormone receptors in cancer have been extensively studied and applied to diagnosis and treatment. Although a number of studies in MSGTs have been published, the rationale for hormone therapy is still controversial due to the disparate results and insufficient number of cases. However, some recent reports have demonstrated that certain salivary gland neoplasms are similar to breast cancer, not only in terms of the pathological features, but also at the molecular level. Here, we shed light on the biological similarity between MSGTs and certain types of breast cancer, and describe the potential use of hormone and additional therapies for MSGTs

Carrier cell-mediated cell lysis of squamous cell carcinoma by squamous cell carcinoma antigen 1 promoter-driven oncolytic adenovirus

The squamous cell carcinoma antigen (SCCA) serves as a serological marker for squamous cell carcinomas. Molecular cloning of the SCCA genomic region has revealed the presence of two tandemly arrayed genes, SCCA1 and SCCA2. We examined the promoter activity of the 5'-flanking proximal region of the SCCA1 gene. Deletion analysis of SCCA1 promoter identified a 175-bp core promoter region and an enhancer region at -525 to -475 bp upstream of the transcription start site. The transcriptional activity of the SCCA1 promoter was up-regulated in squamous cell carcinoma cells, compared with normal keratinocyte, normal non-keratinocyte and adenocarcinoma cells. Five tandem repeats of enhancer increased SCCA1 promoter activity by 4-fold. Oncolytic adenovirus driven by the SCCA1 promoter with 5 tandem repeats of enhancer specifically killed squamous cell carcinoma cells in vitro and in vivo. A549 carrier cells infected with the oncolytic adenovirus induced complete regression of tumor by overcoming immunogenicity and adenovirus-mGM-CSF augmented the antitumor effect of carrier cells. These findings suggest that SCCA1 promoter is a potential target of gene therapy for squamous cell carcinoma

Prognostic significance of interleukin-8 and CD163-positive cell-infiltration in tumor tissues in patients with oral squamous cell carcinoma.

PURPOSE:We investigated whether serum interleukin (IL)-8 reflects the tumor microenvironment and has prognostic value in patients with oral squamous cell carcinoma (OSCC). EXPERIMENTAL DESIGN:Fifty OSCC patients who received radical resection of their tumor(s) were enrolled. Preoperative sera were measured for IL-8 by ELISA. Expression of IL-8 and the infiltration of immune cells in tumor tissues were analyzed by an immunohistochemical staining of surgical specimens. RESULTS:We found that disease-free survival (DFS) was significantly longer in the Stage I/II OSCC patients with low serum IL-8 levels compared to those with high levels (p = 0.001). The tumor expression of IL-8, i.e., IL-8(T) and the density of CD163-positive cells in the tumor invasive front, i.e., CD163(IF) were correlated with the serum IL-8 level (p = 0.033 and p = 0.038, respectively), and they were associated with poor clinical outcome (p = 0.007 and p = 0.002, respectively, in DFS) in all patients. A multivariate analysis revealed that N status, IL-8(T) and CD163(IF) significantly affected the DFS of the patients. Further analysis suggested that combination of N status with serum IL-8, IL-8(T) or CD163(IF) may be a new criterion for discriminating between OSCC patients at high and low risk for tumor relapse. Interestingly, the in vitro experiments demonstrated that IL-8 enhanced generation of CD163-positive M2 macrophages from peripheral blood monocytes, and that the cells produced IL-10. CONCLUSIONS:These findings indicate that IL-8 may be involved in poor clinical outcomes via generation of CD163-positive M2 macrophages, and that these factors in addition to N status may have prognostic value in patients with resectable OSCSS

Immunochemoradiotherapy for Patients with Oral Squamous Cell Carcinoma: Augmentation of OK-432-Induced Helper T Cell 1 Response by 5-FU and X-ray Irradiation

Eighty-one patients with oral squamous cell carcinoma (OSCC) received oral fluoropyrimidine UFT and radiotherapy (RT) with or without an immunotherapeutic agent OK-432. Both overall survival and progression-free survival of patients who received RT + UFT + OK-432 were significantly longer than those of patients who received RT + UFT (P = .0075 and P = .0175, respectively). Clinical response was also more favorable in RT + UFT + OK-432 group than in RT + UFT group (P = .0066). Next, in vitro experiments were conducted to examine the effect of 5-fluorouracil (5-FU) and X-ray irradiation in OK-432-induced immunity. Human peripheral blood mononuclear cells stimulated with OK-432 produced helper T cell 1 (Th1)-type cytokines as well as interleukin-10 (IL-10) and transforming growth factor-β (TGF-β), which are produced by Th2 and regulatory T cells (Tregs), respectively, and are inhibitory in antitumor immunity. OK-432-induced IL-10 and TGF-β but not Th1 cytokines were significantly inhibited by 5-FU and/or X-ray. 5-FU and X-ray also inhibited the expression of mRNAs for GATA-3 and Foxp3, which are transcription factors for Th2 and Tregs, respectively, but not for T-bet, a transcription factor for Th1. In addition, 5-FU and X-ray decreased the expression of mRNAs for suppressor of cytokine signaling 1 (SOCS1) and SOCS3. Antisense oligonucleotides for SOCS1 and SOCS3 markedly reduced OK-432-induced IL-10 and TGF-β. This is the first report clearly demonstrating that OK-432-based immunotherapy significantly enhanced the therapeutic effects of chemoradiotherapy in patients with OSCC as well as elucidating the mechanism of the synergistic effect of immunochemoradiotherapy in which 5-FU and radiation enhanced OK-432-induced Th1 response mediated by the inhibition of SOCS1 and SOCS3 gene expression