Gloria Caldito

Overexpressed eIF4E Is Functionally Active in Surgical Margins of Head and Neck Cancer Patients via Activation of the Akt/Mammalian Target of Rapamycin Pathway

Purpose: Overexpression of eIF4E in surgical margins of head and neck cancer patients is an independent risk factor for recurrence. We hypothesize that overexpressed eIF4E is functionally active in tumor margins through activation of the Akt/mammalian target of rapamycin (mTOR) pathway Experimental Design: Western blots and/or immunohistochemistry were performed to determine whether phosphorylation of mTOR and activation of its downstream molecules eIF4E-binding protein-1 (4E-BP1) and p70 S6 kinase and the upstream modulator of mTOR, Akt, were expressed in margins overexpressing eIF4E. Results: There was a significant association between phospho-4E-BP1 and eIF4E expression of a margin or a significant difference in phospho-4E-BP1 expression between the eIF4E-positive and -negative margins (P < 0.01). A significant association between eIF4E and phospho-p70 S6 kinase as well as eIF4E and phospho-mTOR was also noted (P < 0.05). Western blot analysis indicated a highly significant difference in the phosphorylation status of 4E-BP1 between tumors and resection margins. A total of 89% of the 4E-BP1-expressing margins expressed more of the phosphorylated (β, γ, and δ) isoforms, whereas 81% of the 4E-BP1-expressing tumors expressed more of the unphosphorylated α isoform. A similar difference in Akt activation was noted between eIF4E-positive margins and tumors (P < 0.05). Conclusions: Overexpression of eIF4E is functionally active in tumor margins through activation of the Akt/mTOR signaling pathway. The greater degree of expression of downstream targets and upstream regulators of mTOR in margins compared with the tumors indicates preferential activation of the Akt/mTOR signaling pathway in margins overexpressing eIF4E. Rapamycin analogs can potentially be used as adjuvant therapy for patients with eIF4E-positive margins.

Poor outcome of indigent patients with peripartum cardiomyopathy in the United States

OBJECTIVE Peripartum cardiomyopathy (PPCM) patients from Haiti and South Africa have poor survival and poor left ventricular (LV) function recovery compared with patients from the United States. There are no reported studies of PPCM among the African American population in the United States. We evaluated the prognosis of PPCM in a mostly African American population. STUDY DESIGN We analyzed the clinical and echocardiographic data of 44 (39 African American) patients with PPCM over an 11 year period (1992-2003). RESULTS Thirty-nine patients were indigent and 5 had health insurance. During a mean follow-up of 24.0 (range, 0.1-264) months, 7 (15.9%) patients died and LV function returned to normal in 14 (35%). CONCLUSION LV function recovery and survival rates of PPCM patients observed in our study are similar to those reported from Haiti and South Africa and different from what is generally accepted in the United States.

Comparison of radiosensitizing effects of the mammalian target of rapamycin inhibitor CCI-779 to cisplatin in experimental models of head and neck squamous cell carcinoma

To determine if the mammalian target of rapamycin (mTOR) inhibitor CCI-779 can sensitize head and neck squamous cell carcinoma (HNSCC) to radiotherapy (XRT) and compare the radiosensitizing effects to cisplatin with its known considerable toxicity. Radiosensitizing effects of CCI-779 were assayed on HNSCC cell lines in vitro. CCI-779 (5 mg/kg), cisplatin (1 mg/kg), and XRT (2 Gy) alone and in combination were evaluated for antitumor activity in mice bearing FaDu and SCC40 xenografts. Effects of CCI-779 on radiation-induced activation of the Akt/mTOR pathway were analyzed. Although CCI-779 did not sensitize HNSCC cells to ionizing radiation in vitro, combination of CCI-779 and XRT significantly augmented the in vivo tumor growth-inhibitory effects of XRT and CCI-779 (P < 0.05). In addition, CCI-779 + XRT suppressed tumor growth more effectively than cisplatin + XRT (P < 0.05). CCI-779 + XRT significantly improved survival compared with XRT alone in both cisplatin-sensitive FaDu (P < 0.01) and cisplatin-resistant SCC40 (P < 0.05) xenograft mice. There were no additional benefits of adding cisplatin to CCI-779 + XRT. CCI-779 significantly attenuated irradiation-induced up-regulation of the mTOR pathway, increased apoptosis and displayed potent antiangiogenic activity in FaDu xenografts that was further enhanced by its combination with XRT (P < 0.05), which may explain the mechanism of its selective radiosensitizing effects in vivo and not in vitro. Antitumor activity of XRT was enhanced when combined with CCI-779 in HNSCC xenograft model. CCI-779 + XRT showed antitumor activity superior to conventional chemoradiotherapy with cisplatin. These results pave the way for clinical trials using molecular targeted therapy with CCI-779 in combination with XRT for HNSCC treatment. [Mol Cancer Ther 2009;8(8):2255–65]

Curcumin inhibits carcinogen and nicotine-induced Mammalian target of rapamycin pathway activation in head and neck squamous cell carcinoma.

Curcumin appears to be a safe, bioactive food compound that is a potential chemopreventive for patients at a high risk for head and neck squamous cell carcinoma (HNSCC). Identification and validation of intermediate endpoints is an important step in evaluating chemopreventive agents. AKT/MTOR pathway biomarkers are intrinsic to the carcinogenic process as well as the mechanism of intervention with curcumin. Antiproliferative effects of curcumin were assayed in 9 HNSCC and a keratinocyte cell line. Nicotine, a genotoxic alkaloid involved in tobacco addiction, forms DNA adducts and has been implicated in upper aerodigestive tract cancer promotion. The antiproliferative effects of curcumin were associated with inhibition of the AKT/MTOR pathway in presence and absence of nicotine, which also induced this pathway. Curcumin was highly effective at suppressing growth of SCC40 xenografts and its activity is associated with modulation of MTORs downstream target pS6. Curcumin at 15 mg significantly increased survival (286 ± 37 vs. 350 days) in the 4NQO carcinogenic model survival study. A major cause of lethal progression of HNSCC is local regional migration and invasion of malignant cells, and curcumin significantly inhibited cancer cell migration and invasion in vitro and in vivo where downregulation of pS6 was associated with a significant decrease in MMP-9. This is the first study to demonstrate that curcumin inhibits the adverse effects of nicotine by blocking nicotine-induced activation of the AKT/MTOR pathway in HNSCC, which retards cell migration. These studies indicate that inhibiting the AKT/MTOR pathway with curcumin may be useful as an oral chemopreventive agent. Cancer Prev Res; 3(12); 1586–95. ©2010 AACR.

Comparison of operative and nonoperative management of spinal epidural abscess: a retrospective review of clinical and laboratory predictors of neurological outcome.

OBJECT Spinal epidural abscess (SEA), once considered a rare occurrence, has showed a rapid increase in incidence over the past 20-30 years. Recent reports have advocated for conservative, nonoperative management of this devastating disorder with appropriate risk stratification. Crucial to a successful management strategy are decisive diagnosis, prompt intervention, and consistent follow-up care. The authors present a review of their institutional experience with operative and nonoperative management of SEA to assess morbidity and mortality and the accuracy of microbiological diagnosis. METHODS A retrospective analysis of patient charts, microbiology reports, operative records, and radiology reports was performed on all cases involving patients admitted with the diagnosis of SEA between July 1998 and May 2009. RESULTS Seventy-seven cases were reviewed (median patient age 51.4 years, range 17-78 years). Axial pain was the most common presenting symptom (67.5% of cases). Presenting signs included focal weakness (55.8%), radiculopathy (28.6%), and myelopathy (5.2%). Abscesses were localized to the lumbar, thoracic, and cervical spine, respectively, in 39 (50.6%), 20 (26.0%), and 18 (23.4%) of the patients. Peripheral blood cultures were negative in 32 (45.1%) of 71 patients. Surgical site or interventional biopsy cultures were diagnostic in 52 cases (78.8%), with concordant blood culture results in 36 (60.0%). Methicillin-resistant Staphylococcus aureus (MRSA) was the most frequent isolate in 24 cases (31.2%). The mean time from admission to surgery was 5.5 days (range 0-42 days; within 72 hours in 66.7% of cases). Outcome data were available in 72 cases. At discharge, patient condition had improved or resolved in 57 cases (79.2%), improved minimally in 6 (8.3%), and showed no improvement or worsening in 9 (12.5%). Patient age and premorbid weakness were the only factors found to be significantly associated with outcome (p = 0.04 and 0.012, respectively). CONCLUSIONS These results strongly support immediate surgical decompression combined with appropriately tailored antibiotic therapy for the treatment of symptomatic SEA presenting with focal neurological deficit. The nonsuperiority discovered in other patient subsets may be due to allocation biases between surgically treated and nonsurgically treated cohorts. The present data demonstrate the accuracy of peripheral blood culture for the prediction of causative organisms and confirm patient age as a predictor of outcomes.

Ventricular reservoirs and ventriculoperitoneal shunts for premature infants with posthemorrhagic hydrocephalus : an institutional experience

OBJECT The aim of the study was to analyze the outcome of surgical treatment for posthemorrhagic hydrocephalus in premature infants. METHODS From 1990 to 2006, 32 premature infants underwent surgical treatment for posthemorrhagic hydrocephalus, and their charts were retrospectively reviewed to analyze the complications and outcome with respect to shunt revisions. Multivariate analysis and time series were used to identify factors that influence the outcome in terms of shunt revisions. RESULTS The mean gestational age was 27+/-3.3 weeks, and mean birth weight was 1192+/-660 g. Temporary reservoir placement was performed in 15 patients, while 17 underwent permanent CSF diversion with a ventriculoperitoneal (VP) shunt. In 2 patients, reservoir tapping alone was sufficient to halt the progression of hydrocephalus; 29 patients received VP shunts. The mean follow-up period was 37.3 months. The neonates who received VP shunts first were significantly older (p=0.02) and heavier (p=0.04) than those who initially underwent reservoir placement. Shunts were revised in 14 patients; 42% of patients in the reservoir group had their shunts revised, while 53% of infants who had initially received a VP shunt required a revision. The revision rate per patient in the reservoir group was half that in the direct VP shunt group (p=0.027). No patient in the reservoir group had >2 revisions. Shunt infections developed in 3 patients (10.3%), and 2 patients in the reservoir group died of nonneurological issues related to prematurity. CONCLUSIONS Birth weight and age are useful parameters in decision making. Preterm neonates with low birth weights benefit from initial CSF drainage procedures followed by permanent CSF diversion with respect to the number of shunt revisions.

Clomiphene citrate-induced perturbations during meiotic maturation and cytogenetic abnormalities in mouse oocytes in vivo and in vitro.

OBJECTIVE To determine if clomiphene citrate induces temporal perturbations during meiotic maturation and aneuploidy in mouse oocytes. DESIGN A controlled dose study involving mouse oocytes in vivo and in vitro. SETTING Clinical and academic research setting in a university medical center. INTERVENTION(S) Oocytes were obtained after superovulation and from mature follicles. MAIN OUTCOME MEASURE(S) Cytogenetic analysis of oocytes for aneuploidy, premature centromere separation, premature anaphase, and single chromatids, and the frequencies of metaphase I and diploid oocytes. RESULT(S) Clomiphene citrate resulted in a decrease in the number of ovulated oocytes and a significant (P<.05) increase in hyperploidy at 100 mg/kg in vivo. In vitro, 5.0 microg/mL of clomiphene citrate significantly (P<.05) increased hyperploidy and reduced the proportion of metaphase I oocytes. CONCLUSION(S) These findings suggest that clomiphene citrate has the potential for inducing aneuploidy in mouse oocytes both in vivo and in vitro and that the rate of oocyte maturation is altered after clomiphene exposure in vitro. Additional data are needed to support the results of this study.

Human papillomavirus typing of rare cervical carcinomas

CONTEXT Most cervical tumors are classified as squamous cell carcinoma or adenocarcinoma, both of which are associated with persistent human papillomavirus (HPV) infection. Although other (rare) types represent less than 5% of all cervical carcinomas, it is necessary that these more unusual tumors be studied in the current era of papillomavirus vaccine development, especially in regions with high incidence of cervical cancer. OBJECTIVE To compare papillomavirus types found in histologically rare cervical carcinomas (n = 29) with those types found in common cervical carcinomas (n = 14) archived at the Institute of Cancer in Mexico City, Mexico. DESIGN Paraffin-embedded tissues were received and sectioned at the Louisiana State University Health Sciences Center at Shreveport. One section for each block was stained and examined by 2 pathologists. Specific histologies were categorized into 2 broad groups: common (squamous cell carcinoma or adenocarcinoma) or rare (adenosquamous, papillary, villoglandular, anaplastic, transitional, spindle, adenoid basal, colloid, neuroendocrine, and glassy cell carcinomas). Papillomavirus typing results were based on Roche Molecular Systems line-blot assay. RESULTS No significant difference was found for dual HPV types (21% of both groups), positivity for HPV-16 (66% of rare tumors and 71% of common tumors), or absence of HPV types 16 or 18, although the rare cancers had a greater tendency toward more unusual HPV types (8/29 rare tumors and 1/14 common tumors had no HPV- 16 or HPV-18 DNA). Non-HPV-16/18 types found only in rare tumors included HPV types 52, 84, 26, 35, and 58. CONCLUSIONS Rare types of cervical carcinoma also are associated with papillomavirus, most with types similar to those found in common cervical neoplasias.

Analysis of eIF4E and 4EBP1 mRNAs in head and neck cancer.

The eukaryotic translation initiation factor 4E (eIF4E) in conjunction with its binding protein, 4EBP1, regulates the translation of cap‐dependent mRNAs. An aberrant increase in eIF4E shifts the balance in favor of translation of transcripts that promote cell proliferation and malignancy. eIF4E protein is commonly elevated in head and neck squamous cell carcinomas (HNSCC), and its overexpression is associated with increased recurrence. An underlying mechanism for eIF4E overexpression is gene amplification, and we wanted to determine whether eIF4E mRNA could serve as a prognostic maker of HNSCC.

Recombinant AAV9-TLK1B Administration Ameliorates Fractionated Radiation-Induced Xerostomia

Salivary glands are highly susceptible to radiation, and patients with head and neck cancer treated with radiotherapy invariably suffer from its distressing side effect, salivary hypofunction. The reduction in saliva disrupts oral functions, and significantly impairs oral health. Previously, we demonstrated that adenoviral-mediated expression of Tousled-like kinase 1B (TLK1B) in rat submandibular glands preserves salivary function after single-dose ionizing radiation. To achieve long-term transgene expression for protection of salivary gland function against fractionated radiation, this study examines the usefulness of recombinant adeno-associated viral vector for TLK1B delivery. Lactated Ringers or AAV2/9 with either TLK1B or GFP expression cassette were retroductally delivered to rat submandibular salivary glands (10(11) vg/gland), and animals were exposed, or not, to 20 Gy in eight fractions of 2.5 Gy/day. AAV2/9 transduced predominantly the ductal cells, including the convoluted granular tubules of the submandibular glands. Transgene expression after virus delivery could be detected within 5 weeks, and stable gene expression was observed till the end of study. Pilocarpine-stimulated saliva output measured at 8 weeks after completion of radiation demonstrated >10-fold reduction in salivary flow in saline- and AAV2/9-GFP-treated animals compared with the respective nonirradiated groups (90.8% and 92.5% reduction in salivary flow, respectively). Importantly, there was no decrease in stimulated salivary output after irradiation in animals that were pretreated with AAV2/9-TLK1B (121.5% increase in salivary flow; p<0.01). Salivary gland histology was better preserved after irradiation in TLK1B-treated group, though not significantly, compared with control groups. Single preemptive delivery of AAV2/9-TLK1B averts salivary dysfunction resulting from fractionated radiation. Although AAV2/9 transduces mostly the ductal cells of the gland, their protection against radiation assists in preserving submandibular gland function. AAV2/9-TLK1B treatment could prove beneficial in attenuating xerostomia in patients with head and neck cancer undergoing radiotherapy.