Early detection of squamous cell carcinoma in carcinogen induced oral cancer rodent model by ratiometric activatable cell penetrating peptides.

OBJECTIVES: Ratiometric cell-penetrating-peptides (RACPP) are hairpin-shaped molecules that undergo cleavage by tumor-associated proteases resulting in measurable Cy5:Cy7 fluorescence ratiometric change to label cancer in vivo. We evaluated an MMP cleavable RACPP for use in the early detection of malignant lesions in a carcinogen-induced rodent tumor model. METHODS: Wild-type immune-competent mice were given 4-nitroquinoline-oxide (4NQO) for 16weeks. Oral cavities from live mice that had been intravenously administered MMP cleavable PLGC(Me)AG-RACPP were serially imaged from week 11 through week 21 using white-light reflectance and Cy5:Cy7 ratiometric fluorescence. RESULTS: In an initial study we found that at week 21 nearly all mice (13/14) had oral cavity lesions, of which 90% were high-grade dysplasia or invasive carcinoma. These high-grade lesions were identifiable with white light reflectance and RACPP Cy5:Cy7 ratiometric fluorescence with similar detectability, Area Under Curve (AUC) for RACPP detection was 0.97 (95% Confidence interval (CI)=0.92-1.02, p<0.001), sensitivity=89%, specificity=100%. In a follow up study, oral cavity lesions generated by 4NQO were imaged and histologically analyzed at weeks 16, 18 and 21. In this study we showed that RACPP-fluorescence detection positively identified 15 squamous cell carcinomas (in 6 separate mice) that were poorly visible or undetectable by white light reflectance. CONCLUSIONS: RACPP ratiometric fluorescence can be used to accurately detect carcinogen-induced carcinoma in immunocompetent mice that are poorly visible or undetectable by white light reflectance.

Semimembranosus muscle herniation: a rare case with emphasis on muscle biomechanics.

Muscle herniations are rare and most reported cases involve muscles of the lower leg. We use a case of muscle herniation involving the semimembranosus muscle, presenting as a painful mass in an adolescent male after an unspecified American football injury, to highlight a simple concept of muscle biomechanics as it pertains to muscle hernia(s): decreased traction upon muscle fibers can increase conspicuity of muscle herniation(s)-this allows a better understanding of the apt provocative maneuvers to employ, during dynamic ultrasound or magnetic resonance imaging, in order to maximize diagnostic yield and, thereby, limit patient morbidity related to any muscle herniation. Our patient subsequently underwent successful decompressive fasciotomy and has since returned to his normal daily activities.

Lymph Node Yield as a Predictor of Survival in Pathologically Node Negative Oral Cavity Carcinoma.

OBJECTIVE: Even after a pathologically node-negative (pN0) neck dissection for oral cavity squamous cell carcinoma (SCC), patients may develop regional recurrence. In this study, we (1) hypothesize that an increased number of lymph nodes removed (lymph node yield) in patients with pN0 oral SCC predicts improved survival and (2) explore predictors of survival in these patients using a multivariable model. STUDY DESIGN: Case series with chart review. SETTING: Administrative database analysis. SUBJECTS AND METHODS: The SEER database was queried for patients diagnosed with all-stage oral cavity SCC between 1988 and 2009 who were determined to be pN0 after elective lymph node dissection. Demographic and treatment variables were extracted. The association of lymph node yield with 5-year all-cause survival was studied with multivariable survival analyses. RESULTS: A total of 4341 patients with pN0 oral SCC were included in this study. The 2 highest lymph node yield quartiles (representing >22 nodes removed) were found to be significant predictors of overall survival (22-35 nodes: hazard ratio [HR] = 0.854, P = .031; 36-98 nodes: HR = 0.827, P = .010). Each additional lymph node removed during neck dissection was associated with increased survival (HR = 0.995, P = .022). CONCLUSION: These data suggest that patients with oral SCC undergoing elective neck dissection may experience an overall survival benefit associated with greater lymph node yield. Mechanisms behind the demonstrated survival advantage are unknown. Larger nodal dissections may remove a greater burden of microscopic metastatic disease, diminishing the likelihood of recurrence. Lymph node yield may serve as an objective measure of the adequacy of lymphadenectomy.

Combined TP53 mutation/3p loss correlates with decreased radiosensitivity and increased matrix-metalloproteinase activity in head and neck carcinoma.

OBJECTIVE: Patients with head and neck squamous cell carcinoma (HNSCC) containing TP53 mutation and 3p deletion ("double-hit") have poorer prognosis compared to patients with either event alone ("single-hit"). The etiology for worse clinical outcomes in patients with "double-hit" cancers is unclear. We compared radiosensitivity of cell lines containing both TP53 mutations and deletion of Fragile Histidine Triad (FHIT, the gene most commonly associated with 3p deletion) to "single-hit" lines with only TP53 mutation. We compared radiosensitivity in a "single-hit" cell line with TP53 mutation converted to "double-hit" using RNA interference targeting FHIT. Finally, we compared matrixmetalloproteinase-2/9 (MMP-2/9) activity, a previously-established biomarker for tumor aggressiveness, in xenograft tumors derived from these cell lines. MATERIALS/METHODS: TP53 mutation and FHIT deletion profiles of HNSCC lines were established using Cancer Cell Line Encyclopedia (CCLE). We used RNA-interference to convert a "single-hit" cell line (SCC4) to "double-hit". Cultured cells were examined for radiosensitivity and cisplatin sensitivity. MMP-2/9 activity was evaluated in "double-hit" versus "single-hit" tumors using ratiometric activatable cell-penetrating peptide (RACPP) in tongue (n=17) and flank xenografts (n=4). RESULTS: Radiotherapy caused greater double-stranded DNA breaks in "single-hit" vs naturally occurring and engineered "double-hit" cells. In-vivo, "double-hit" xenografts demonstrated higher MMP-2/9 activity compared to "single-hit" xenografts (p<0.01). There was no difference in cisplatin sensitivity between the cell lines. CONCLUSIONS: TP53 mutation combined with FHIT deletion correlates with decreased radiosensitivity in HNC cell lines. Xenograft from "double-hit" cells exhibit increased MMP-2/9 activity. These findings may in part account for the worse clinical outcome seen in patients with HNSCC "double-hit" tumors.