Tetrathiomolybdate inhibits head and neck cancer metastasis by decreasing tumor cell motility, invasiveness and by promoting tumor cell anoikis

<p>Abstract</p> <p>Background</p> <p>The metastatic spread of solid tumors is directly or indirectly responsible for most cancer-related deaths. Tumor metastasis is very complex and this process requires a tumor cell to acquire enhanced motility, invasiveness and anoikis resistance to successfully establish a tumor at a distal site. Metastatic potential of tumor cells is directly correlated with the expression levels of several angiogenic cytokines. Copper is a mandatory cofactor for the function of many of these angiogenic mediators as well as other proteins that play an important role in tumor cell motility and invasiveness. We have previously shown that tetrathiomolybdate (TM) is a potent chelator of copper and it mediates its anti-tumor effects by suppressing tumor angiogenesis. However, very little is known about the effect of TM on tumor cell function and tumor metastasis. In this study, we explored the mechanisms underlying TM-mediated inhibition of tumor metastasis.</p> <p>Results</p> <p>We used two <it>in vivo </it>models to examine the effects of TM on tumor metastasis. Animals treated with TM showed a significant decrease in lung metastasis in both <it>in vivo </it>models as compared to the control group. In addition, tumor cells from the lungs of TM treated animals developed significantly smaller colonies and these colonies had significantly fewer tumor cells. TM treatment significantly decreased tumor cell motility and invasiveness by inhibiting lysyl oxidase (LOX) activity, FAK activation and MMP2 levels. Furthermore, TM treatment significantly enhanced tumor cell anoikis by activating p38 MAPK cell death pathway and by downregulating XIAP survival protein expression.</p> <p>Conclusions</p> <p>Taken together, these results suggest that TM is a potent suppressor of head and neck tumor metastasis by modulating key regulators of tumor cell motility, invasiveness and anoikis resistance.</p

Prevention of wound complications following salvage laryngectomy using free vascularized tissue

Background. Total laryngectomy following radiation therapy or concurrent chemoradiation therapy is associated with unacceptably high complication rates because of wound healing difficulties. With an ever increasing reliance on organ preservation protocols as primary treatment for advanced laryngeal cancer, the surgeon must develop techniques to minimize postoperative complications in salvage laryngectomy surgery. We have developed an approach using free tissue transfer in an effort to improve tissue vascularity, reinforce the pharyngeal suture line, and minimize complications in this difficult patient population. The purpose of this study was to outline our technique and determine the effectiveness of this new approach. Methods. We conducted a retrospective review of a prospective cohort and compared it with a historical group (surgical patients of Radiation Therapy Oncology Group (RTOG)-91-11 trial). Eligibility criteria for this study included patients undergoing salvage total laryngectomy following failed attempts at organ preservation with either high-dose radiotherapy or concurrent chemo/radiation therapy regimen. Patients were excluded if the surgical defect required a skin paddle for pharyngeal closure. The prospective cohort consisted of 14 consecutive patients (10 males, 4 females; mean age, 58 years) who underwent free tissue reinforcement of the pharyngeal suture line following total laryngectomy. The historical comparison group consisted of 27 patients in the concomitant chemoradiotherapy arm of the RTOG-91-11 trial who met the same eligibility criteria (26 males, 1 female; mean age, 57 years) but did not undergo free tissue transfer or other form of suture line reinforcement. Minimum follow-up in both groups was 12 months. Results. The overall pharyngocutaneous fistula rate was similar between groups—4/14 (29%) in the flap group, compared with 8/27 (30%) in the RTOG-91-11 group. There were no major wound complications in the flap group, compared with 4 (4/27, 14.8%) in the RTOG-91-11 group. There were no major fistulas in the flap group, compared with 3/27 (11.1%) in the RTOG-91-11 group. The rate of pharyngeal stricture requiring dilation was 6/14 (42%) in the flap group, compared with 7/27 (25.9%) in the RTOG-91-11 group. In our patients, the rate of tracheoesophageal speech was 14/14 (100%), and complete oral intake was achieved in 13/14 (93%) patients. Voice-Related Quality of Life Measure (V-RQOL) and Performance Status Scale for Head and Neck Cancer Patients (PSS-HN) scores suggest that speech and swallowing functions are reasonable following free flap reinforcement. Conclusions. Free vascularized tissue reinforcement of primary pharyngeal closure in salvage laryngectomy following failed organ preservation is effective in preventing major wound complications but did not reduce the overall fistula rate. Fistulas that developed following this technique were relatively small, did not result in exposed major vessels, and were effectively treated with outpatient wound care rather than readmission to the hospital or return to operating room. Speech and swallowing results following this technique were comparable to those following total laryngectomy alone. © 2007 Wiley Periodicals, Inc. Head Neck 2007Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/56020/1/20492_ftp.pd

Chemotherapy alone for organ preservation in advanced laryngeal cancer

Background. For patients with advanced laryngeal cancer, a trial was designed to determine if chemotherapy alone, in patients achieving a complete histologic complete response after a single neoadjuvant cycle, was an effective treatment with less morbidity than concurrent chemoradiotherapy. Methods. Thirty-two patients with advanced laryngeal or hypopharyngeal cancer received 1 cycle of induction chemotherapy, and subsequent treatment was decided based on response. Results. A histologic complete response was achieved in 4 patients and were treated with chemotherapy alone. All 4 patients' cancer relapsed in the neck and required surgery and postoperative radiotherapy (RT). Twenty-five patients were treated with concomitant chemoradiation. Three patients were treated with surgery. Overall survival and disease-specific survival at 3 years were 68% and 78%, respectively. Conclusion. Chemotherapy alone is not feasible for long-term control of regional disease in patients with advanced laryngeal cancer even when they achieve a histologic complete response at the primary site. © 2009 Wiley Periodicals, Inc. Head Neck, 2010Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77508/1/21285_ftp.pd

Biomarkers in advanced larynx cancer

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102058/1/lary24245.pd

Salivary Gland Sparing and Improved Target Irradiation by Conformal and Intensity Modulated Irradiation of Head and Neck Cancer

The goals of this study were to facilitate sparing of the major salivary glands while adequately treating tumor targets in patients requiring comprehensive bilateral neck irradiation (RT), and to assess the potential for improved xerostomia. Since 1994 techniques of target irradiation and locoregional tumor control with conformal and intensity modulated radiation therapy (IMRT) have been developed. In patients treated with these modalities, the salivary flow rates before and periodically after RT have been measured selectively from each major salivary gland and the residual flows correlated with glands’ dose volume histograms (DVHs). In addition, subjective xerostomia questionnaires have been developed and validated. The pattern of locoregional recurrence has been examined from computed tomography (CT) scans at the time of recurrence, transferring the recurrence volumes to the planning CT scans, and regenerating the dose distributions at the recurrence sites. Treatment plans for target coverage and dose homogeneity using static, multisegmental IMRT were found to be significantly better than standard RT plans. In addition, significant parotid gland sparing was achieved in the conformal plans. The relationships among dose, irradiated volume, and the residual saliva flow rates from the parotid glands were characterized by dose and volume thresholds. A mean radiation dose of 26 Gy was found to be the threshold for preserved stimulated saliva flow. Xerostomia questionnaire scores suggested that xerostomia was significantly reduced in patients irradiated with bilateral neck, parotid-sparing RT, compared to patients with similar tumors treated with standard RT. Examination of locoregional tumor recurrence patterns revealed that the large majority of recurrences occurred inside targets, in areas that had been judged to be at high risk and that had received RT doses according to the perceived risk. Tangible gains in salivary gland sparing and target coverage are being achieved, and an improvement in some measures of quality of life is suggested by our findings. Additional reduction of xerostomia may be achieved by further sparing of the salivary glands and the non-involved oral cavity. A mean parotid gland dose of ≤ 26 Gy should be a planning objective if significant parotid function preservation is desired. The pattern of recurrence suggests that careful escalation of the dose to areas judged to be at highest risk may improve tumor control.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/41298/1/268_2003_Article_7105.pd

Dysregulation of MicroRNA-34a Expression in Head and Neck Squamous Cell Carcinoma Promotes Tumor Growth and Tumor Angiogenesis

MicroRNAs (miRs) are small non-coding RNAs that play an important role in cancer development where they can act as oncogenes or as tumor-suppressors. miR-34a is a tumor-suppressor that is frequently downregulated in a number of tumor types. However, little is known about the role of miR-34a in head and neck squamous cell carcinoma (HNSCC).miR-34a expression in tumor samples, HNSCC cell lines and endothelial cells was examined by real time PCR. Lipofectamine-2000 was used to transfect miR-34a in HNSCC cell lines and human endothelial cells. Cell-proliferation, migration and clonogenic survival was examined by MTT, Xcelligence system, scratch assay and colony formation assay. miR-34a effect on tumor growth and tumor angiogenesis was examined by in vivo SCID mouse xenograft model. Our results demonstrate that miR-34a is significantly downregulated in HNSCC tumors and cell lines. Ectopic expression of miR-34a in HNSCC cell lines significantly inhibited tumor cell proliferation, colony formation and migration. miR-34a overexpression also markedly downregulated E2F3 and survivin levels. Rescue experiments using microRNA resistant E2F3 isoforms suggest that miR-34a-mediated inhibition of cell proliferation and colony formation is predominantly mediated by E2F3a isoform. In addition, tumor samples from HNSCC patients showed an inverse relationship between miR-34a and survivin as well as miR-34a and E2F3 levels. Overexpression of E2F3a completely rescued survivin expression in miR-34a expressing cells, thereby suggesting that miR-34a may be regulating survivin expression via E2F3a. Ectopic expression of miR-34a also significantly inhibited tumor growth and tumor angiogenesis in a SCID mouse xenograft model. Interestingly, miR-34a inhibited tumor angiogenesis by blocking VEGF production by tumor cells as well as directly inhibiting endothelial cell functions.Taken together, these findings suggest that dysregulation of miR-34a expression is common in HNSCC and modulation of miR34a activity might represent a novel therapeutic strategy for the treatment of HNSCC