Evaluation of Efficacy of Curcumin along with Lycopene and Piperine in the Management of Oral Submucous Fibrosis.

CONTEXT: Oral submucous fibrosis (OSMF) is a high-risk premalignant condition of the oral cavity and oropharynx. Complete regression of the disease is still not possible with available treatment modalities. AIMS: The aim of the study was to evaluate the efficacy of curcumin, lycopene, and piperine as a combination in the management of OSMF. SETTINGS AND DESIGN: Efficacy was evaluated on the basis of improvement in clinical parameters (i.e., visual Analog Scale [VAS]) score for burning sensation, mouth opening (MO), mucosal flexibility (MF), and tongue protrusion [TP]). MATERIALS AND METHODS: Forty patients clinically and histopathologically diagnosed with OSMF were included in the study; patients were administered with the above-stated drug combination, and clinical parameters were evaluated at regular intervals to compare the pre- and post-treatment measurements. STATISTICAL ANALYSIS USED: Paired t-test was done to evaluate significance of the results. RESULTS: Highly significant improvement was observed for posttreatment reduction in VAS score for burning sensation and increase in MO (P < 0.001). Significant improvement was also observed in the increase of MF and TP. Posttreatment histopathological evaluation also revealed reepithelialization, indicated by significant increase in the epithelial thickness as found through quantitative image analysis. Immunohistochemical studies with Col1A1 showed decrease in collagen deposition. CONCLUSIONS: Taken together, the present study proposes the usage of combination drug therapy for the management of OSMF as an effective and affordable way.

Oral squamous cell carcinoma profile in North-Eastern regions of India from habits to histopathology: A hospital-based study.

BACKGROUND: Head and neck cancers constitute about 5%-8% of total body cancers in Europe, America, but in India, this figure is somewhat higher. The aim of this study is to evaluate the current burden of oral cancers in India, particularly North-East India. MATERIALS AND METHODS: A full-length study starting from patient counseling to clinical and histopathological examination and grading was planned. The study was conducted under the guidance of clinician, oral surgeon, oral pathologists, and statistician. RESULTS: In the 3 years study, all the patients with oral lesions are examined clinically, out of them suspected oral cancer patients were histopathologically confirmed as oral squamous cell carcinoma patient. The socioeconomic profile of oral cancer patients in relation to all examined patients was summarized, and results are drawn. CONCLUSION: The studied population is heavily indulgent tobacco consumption. Education for cancer prevention, early detection, and treatment is needed.

Embryonal rhabdomyosarcoma: A rare oral tumor.

Rhabdomyosarcoma is the malignant neoplasm of striated muscle and a relatively uncommon tumor of the oral cavity. Embryonal variety is the most common subtype, observed in children below 10 years of age but occasionally seen in adolescents and young adults. The present report describes a case of embryonal rhabdomyosarcoma in the left posterior buccal mucosa, with extension in the adjacent alveolus, soft palate, oropharynx and nasopharynx of a 17-year-old female.

Demographic and histopathological variation of ameloblastoma: A hospital-based study.

CONTEXT: Ameloblastoma is the second most common odontogenic tumor after odontoma which occurs exclusively in the jaws and very rarely in the sinonasal cavities. AIMS: The aim of the study was to determine the demographic and histopathological variations of ameloblastoma in Eastern Indian population by retrospectively comparing and evaluating diagnosed cases of ameloblastoma using different parameters. MATERIALS AND METHODS: Histopathologically diagnosed cases of ameloblastoma retrieved from past records of the Department of Oral Pathology were selected for the study. Totally, 148 cases were isolated from record of previous 7 years. The patients were divided according to (a) gender, (b) age group, (c) site of the lesion and (d) histopathological types. The findings of this study were compared with those available in literature. STATISTICAL ANALYSIS USED: This is a retrospective study, mean and standard deviation was calculated. RESULTS: Among 148 patients, 88 (59.45%) were male and 60 (40.55%) were female. A maximum number of cases (101 of 148) of ameloblastoma were found in the second to fourth decades of life. Mandiblular posterior region was commonly involved (48.6%). Solid/multicystic variety was found in 63.1% followed by unicystic with 21.5%. We found one case each of extraosseous and desmoplastic ameloblastoma. It was difficult for panel of experienced oral pathologists to pinpoint the exact type in 15 (10%) cases, this was due to mixture of follicular and plexiform variety with equal presence of both types of architecture, without predominance of any variety in particular. CONCLUSIONS: These data may serve as baseline information on occurrence of various histopathological types of ameloblastoma in Eastern Indian population and helps comparing it with other similar studies conducted in different geographic population.

Pnck overexpression in HER-2 gene-amplified breast cancer causes Trastuzumab resistance through a paradoxical PTEN-mediated process.

The gene for Pregnancy Up-regulated Non-ubiquitous Calmodulin Kinase (Pnck), a novel calmodulin kinase, is expressed in roughly one-third of human breast tumors, but not in adjoining normal tissues. Pnck alters EGFR stability and function, prompting this study to determine if Pnck expression has implications for HER-2 function and HER-2-directed therapy. The frequency of Pnck expression in HER-2-amplified breast cancer was examined by immunohistochemistry, and the impact of Pnck expression in the presence of HER-2 amplification on cancer cell proliferation, clonogenicity, cell-cycle progression, and Trastuzumab sensitivity was examined in vitro by transfection of cells with Pnck. Cell signaling was probed by Western blot analysis and shRNA-mediated PTEN knockdown. Over 30 % of HER-2 amplified tumors were found to express Pnck. Expression of Pnck in SkBr3 cells resulted in increased proliferation, clonal growth, cell-cycle progression, and Trastuzumab resistance. Pnck expression increases Hsp27 expression, Trastuzumab partial agonist activity on HER-2 Y1248 phosphorylation, and suppressed extracellular signal-regulated kinase (ERK1/2) activity. Knockdown of endogenous PTEN upregulated ERK1/2 activity, inhibited cellular proliferation, and partially sensitized Pnck/SKBr3 cells to Trastuzumab treatment. Increased proliferation of the Pnck/SKBr3 cells was observed following expression of protein phosphatase active and lipid phosphatase dead PTEN mutant but not the total phosphatase dead PTEN mutant. Co-overexpression of HER-2 and Pnck results in enhanced tumor cell proliferation and Trastuzumab resistance that is paradoxically dependent on PTEN protein phosphatase activity. This suggests that Pnck may be a marker of Trastuzumab resistance and possibly a therapeutic target.

PTEN-mediated ERK1/2 inhibition and paradoxical cellular proliferation following Pnck overexpression.

Pregnancy upregulated non-ubiquitous calmodulin kinase (Pnck), a novel calmodulin kinase, is significantly overexpressed in breast and renal cancers. We present evidence that at high cell density, overexpression of Pnck in HEK 293 cells inhibits serum-induced extracellular signal-regulated kinase (ERK1/ERK2) activation. ERK1/2 inhibition is calcium-dependent and Pnck kinase activity is required for ERK1/2 inhibition, since expression of a kinase-dead (K44A) and a catalytic loop phosphorylation mutant (T171A) Pnck protein is unable to inhibit ERK1/2 activity. Ras is constitutively active at high cell density, and Pnck does not alter Ras activation, suggesting that Pnck inhibition of ERK1/2 activity is independent of Ras activity. Pnck inhibition of serum-induced ERK1/2 activity is lost in cells in which phosphatase and tensin homolog (PTEN) is suppressed, suggesting that Pnck inhibition of ERK1/2 activity is mediated by PTEN. Overexpression of protein phosphatase-active but lipid phosphatase-dead PTEN protein inhibits ERK1/2 activity in control cells and enhances Pnck-mediated ERK1/2 inhibition, suggesting that Pnck increases availability of protein phosphatase active PTEN for ERK1/2 inhibition. Pnck is a stress-responsive kinase; however, serum-induced p38 MAP kinase activity is also downregulated by Pnck in a Pnck kinase- and PTEN-dependent manner, similar to ERK1/2 inhibition. Pnck overexpression increases proliferation, which is inhibited by PTEN knockdown, implying that PTEN acts as a paradoxical promoter of proliferation in ERK1/2 and p38 MAP kinase phosphorylation-inhibited, Pnck-overexpressing cells. Overall, these data reveal a novel function of Pnck in the regulation of ERK1/2 and p38 MAP kinase activity and cell proliferation, which is mediated by paradoxical PTEN functions. The possible biological implications of these data are discussed.

Trans-resveratrol boronic acid exhibits enhanced anti-proliferative activity on estrogen-dependent MCF-7 breast cancer cells.

Resveratrol (RSV), a natural compound present in the skin and seeds of red grapes, is considered a phytoestrogen and has structural similarity to the synthetic estrogen diethylstilbestrol. RSV inhibits tumor cell growth in estrogen receptor-positive (ER+) and negative (ER-) breast cancer cell lines resulting in cell specific regulation of the G1/S and G2/M stages of the cell cycle. However apoptotic cell death was only observed in ER+ MCF-7 cells. In this study, we designed and synthesized boronic acid derivative of RSV and evaluated their biological effects on ER+ MCF-7 breast cancer cells. The trans-4 analog inhibited the growth of MCF-7 cells and is not a substrate for p-glycoprotein. The trans-4 analog induces G1 cell cycle arrest, which coincides with marked inhibition of G1 cell cycle proteins and a greater pro-apoptotic effect. Finally, the trans-4 analog had no effect on the estrogen-stimulated growth of MCF-7 cells. Our results demonstrate that the trans-4 analog inhibits MCF-7 breast cancer cells by a different mechanism of action than that of RSV (S-phase arrest), and provides a new class of novel boronic acids of RSV that inhibit breast cancer cell growth.

Ewing's sarcoma of mandible: A case report and review of Indian literature.

Ewing's sarcoma (ES) is a rare malignancy primarily affecting skeletal system and it is commonly diagnosed in children and young adults. It seldom occurs in the head and neck region. ES has poor prognosis because of uncontrolled metastatic potential making early diagnosis and intervention critical for survival of the patient. This paper reports a rare case of ES involving mandible in an 8-year-old girl with clinical, radiological, histopathological and immunohistochemical features.

Fluorescent cyclin-dependent kinase inhibitors block the proliferation of human breast cancer cells.

Inhibitors of cyclin-dependent kinases (CDKs) are an emerging class of drugs for the treatment of cancers. CDK inhibitors are currently under evaluation in clinical trials as single agents and as sensitizers in combination with radiation therapy and chemotherapies. Drugs that target CDKs could have important inhibitory effects on cancer cell cycle progression, an extremely important mechanism in the control of cancer cell growth. Using rational drug design, we designed and synthesized fluorescent CDK inhibitors (VMY-1-101 and VMY-1-103) based on a purvalanol B scaffold. The new agents demonstrated more potent CDK inhibitory activity, enhanced induction of G2/M arrest and modest apoptosis as compared to purvalanol B. Intracellular imaging of the CDK inhibitor distribution was performed to reveal drug retention in the cytoplasm of treated breast cancer cells. In human breast cancer tissue, the compounds demonstrated increased binding as compared to the fluorophore. The new fluorescent CDK inhibitors showed undiminished activity in multidrug resistance (MDR) positive breast cancer cells, indicating that they are not a substrate for p-glycoprotein. Fluorescent CDK inhibitors offer potential as novel theranostic agents, combining therapeutic and diagnostic properties in the same molecule.

Pnck induces ligand-independent EGFR degradation by probable perturbation of the Hsp90 chaperone complex.

We have recently described a novel role for pregnancy-upregulated non-ubiquitous calmodulin kinase (Pnck) in the induction of ligand-independent epidermal growth factor receptor (EGFR) degradation (Deb TB, Coticchia CM, Barndt R, Zuo H, Dickson RB, and Johnson MD. Am J Physiol Cell Physiol 295: C365-C377, 2008). In the current communication, we explore the probable mechanism by which Pnck induces ligand-independent EGFR degradation. Pnck-induced EGFR degradation is calcium/calmodulin independent and is regulated by cell density, with the highest EGFR degradation observed at low cell density. Pnck is a novel heat shock protein 90 (Hsp90) client protein that can be co-immunoprecipitated with Hsp90. Treatment of Pnck-overexpressing cells with the pharmacologic Hsp90 inhibitor geldanamycin results in enhanced EGFR degradation, and destruction of Pnck. In cells in which Pnck is inducing EGFR degradation, we observed that Hsp90 exhibits reduced electrophoretic mobility, and through mass spectrometric analysis of immunopurified Hsp90 protein we demonstrated enhanced phosphorylation at threonine 89 and 616 (in both Hsp90-α and -ß) and serine 391 (in Hsp90-α). Kinase-active Pnck protein is degraded by the proteasome, concurrent with EGFR degradation. A Pnck mutant (T171A) protein with suppressed kinase activity induced EGFR degradation to essentially the same level as wild-type (WT) Pnck, suggesting that Pnck kinase activity is not required for the induction of EGFR degradation. Although EGFR is degraded, overexpression of WT Pnck paradoxically promoted cellular proliferation, whereas cells expressing mutant Pnck (T171A) were growth inhibited. WT Pnck promoted S to G(2) transition, but cells expressing the mutant exhibited higher residency time in S phase. Basal MAP kinase activity was inhibited by WT Pnck but not by mutant T171A Pnck protein. Cyclin-dependent kinase (Cdk) inhibitor p21/Cip-1/Waf-1 was transcriptionally suppressed downstream to MAP kinase inhibition by WT Pnck, but not the mutant protein. Collectively, these data suggest that 1) Pnck induces ligand-independent EGFR degradation most likely through perturbation of Hsp90 chaperone activity due to Hsp90 phosphorylation, 2) EGFR degradation is coupled to proteasomal degradation of Pnck, and 3) modulation of basal MAP kinase activity, p21/Cip-1/Waf-1 expression, and cellular growth by Pnck is independent of Pnck-induced ligand-independent EGFR degradation.

Calmodulin modulates Akt activity in human breast cancer cell lines.

Growth factor-induced activation of Akt occurs in the majority of human breast cancer cell lines resulting in a variety of cellular outcomes, including suppression of apoptosis and enhanced survival. We demonstrate that epidermal growth factor (EGF)-initiated activation of Akt is mediated by the ubiquitous calcium sensing molecule, calmodulin, in the majority of human breast cancer cell lines. Specifically, in estrogen receptor (ER)-negative, but not ER-positive, breast cancer cells, Akt activation is abolished by treatment with the calmodulin antagonist, W-7. Suppression of calmodulin expression by siRNAs against all three calmodulin genes in c-Myc-overexpressing mouse mammary carcinoma cells results in significant inhibition of EGF-induced Akt activation. Additionally, transient expression of constitutively active Akt (Myr-Akt) can overcome W-7-mediated suppression of Akt activation. These results confirm the involvement of calmodulin in the Akt pathway. The calmodulin independence of EGF-initiated Akt signaling in some cells was not explained by calmodulin expression level. Additionally, it was not explained by ER status or activation, since removal of estrogen and ablation of the ER did not convert the ER-positive, W-7 insensitive, MCF-7 cell line to calmodulin dependent signaling. However, forced overexpression of either epidermal growth factor receptor (EGFR) or ErbB2 did partially restore calmodulin dependent EGF-stimulated Akt activation. This is consistent with observation that W-7 sensitive cells tend to be estrogen independent and express high levels of EGFR family members. In an attempt to address how calmodulin is regulating Akt activity, we looked at localization of fluorescently tagged Akt and calmodulin in MCF-7 and SK-BR-3 cells. We found that both Akt and calmodulin translocate to the membrane after EGF-stimulation, and this translocation to the same sub-cellular compartment is inhibited by the calmodulin inhibitor W-7. Thus, calmodulin may be regulating Akt activity by modulating its sub-cellular location and is a novel target in the poor prognosis, ER-negative subset of breast cancers.

Pregnancy-upregulated nonubiquitous calmodulin kinase induces ligand-independent EGFR degradation.

We describe here an important function of the novel calmodulin kinase I isoform, pregnancy-upregulated nonubiquitous calmodulin kinase (Pnck). Pnck (also known as CaM kinase Ibeta(2)) was previously shown to be differentially overexpressed in a subset of human primary breast cancers, compared with benign mammary epithelial tissue. In addition, during late pregnancy, Pnck mRNA was shown to be strongly upregulated in epithelial cells of the mouse mammary gland exhibiting decreased proliferation and terminal differentiation. Pnck mRNA is also significantly upregulated in confluent and serum-starved cells, compared with actively growing proliferating cells (Gardner HP, Seung HI, Reynolds C, Chodosh LA. Cancer Res 60: 5571-5577, 2000). Despite these suggestive data, the true physiological role(s) of, or the signaling mechanism(s) regulated by Pnck, remain unknown. We now report that epidermal growth factor receptor (EGFR) levels are significantly downregulated in a ligand-independent manner in human embryonic kidney-293 (HEK-293) cells overexpressing Pnck. MAP kinase activation was strongly inhibited by EGFR downregulation in the Pnck-overexpressing cells. The EGFR downregulation was not the result of reduced transcription of the EGFR gene but from protea-lysosomal degradation of EGFR protein. Knockdown of endogenous Pnck mRNA levels by small interfering RNA transfection in human breast cancer cells resulted in upregulation of unliganded EGFR, consistent with the effects observed in the overexpression model of Pnck-mediated ligand-independent EGFR downregulation. Pnck thus emerges as a new component of the poorly understood mechanism of ligand-independent EGFR degradation, and it may represent an attractive therapeutic target in EGFR-regulated oncogenesis.

Calmodulin-mediated activation of Akt regulates survival of c-Myc-overexpressing mouse mammary carcinoma cells.

c-Myc-overexpressing mammary epithelial cells are proapoptotic; their survival is strongly promoted by epidermal growth factor (EGF). We now demonstrate that EGF-induced Akt activation and survival in transgenic mouse mammary tumor virus-c-Myc mouse mammary carcinoma cells are both calcium/calmodulin-dependent. Akt activation is abolished by the phospholipase C-gamma inhibitor U-73122, by the intracellular calcium chelator BAPTA-AM, and by the specific calmodulin antagonist W-7. These results implicate calcium/calmodulin in the activation of Akt in these cells. In addition, Akt activation by serum and insulin is also inhibited by W-7. EGF-induced and calcium/calmodulin-mediated Akt activation occurs in both tumorigenic and non-tumorigenic mouse and human mammary epithelial cells, independent of their overexpression of c-Myc. These results imply that calcium/calmodulin may be a common regulator of Akt activation, irrespective of upstream receptor activator, mammalian species, and transformation status in mammary epithelial cells. However, only c-Myc-overexpressing mouse mammary carcinoma cells (but not normal mouse mammary epithelial cells) undergo apoptosis in the presence of the calmodulin antagonist W-7, indicating the vital selective role of calmodulin for survival of these cells. Calcium/calmodulin-regulated Akt activation is mediated directly by neither calmodulin kinases nor phosphatidylinositol 3-kinase (PI-3 kinase). Pharmacological inhibitors of calmodulin kinase kinase and calmodulin kinases II and III do not inhibit EGF-induced Akt activation, and calmodulin antagonist W-7 does not inhibit phosphotyrosine-associated PI-3 kinase activation. Akt is, however, co-immunoprecipitated with calmodulin in an EGF-dependent manner, which is inhibited by calmodulin antagonist W-7. We conclude that calmodulin may serve a vital regulatory function to direct the localization of Akt to the plasma membrane for its activation by PI-3 kinase.

Ligand regulates epidermal growth factor receptor kinase specificity: activation increases preference for GAB1 and SHC versus autophosphorylation sites.

The epidermal growth factor receptor (EGFR) kinase catalyzes phosphorylation of tyrosines in its C terminus and in other cellular targets upon epidermal growth factor (EGF) stimulation. Here, by using peptides derived from EGFR autophosphorylation sites and cellular substrates, we tested the hypothesis that ligand may function to regulate EGFR kinase specificity by modulating the binding affinity of peptide sequences to the active site. Measurement of the steady-state kinetic parameters, K(m) and k(cat), revealed that EGF did not affect the binding of EGFR peptides but increased the binding affinity for peptides corresponding to the major EGFR-mediated phosphorylation sites of the adaptor proteins Gab1 (Tyr-627) and Shc (Tyr-317), and for peptides containing the previously identified optimal EGFR kinase substrate sequence EEEEYFELV (3-7-fold). Conversely, EGF stimulation increased k(cat) approximately 5-fold for all peptides. Thus, ligand changed the relative preference of the EGFR kinase for substrates as evidenced by EGF increases of approximately 5-fold in the specificity constants (k(cat)/K(m)) for EGFR peptides, whereas approximately 15-40-fold increases were observed for other peptides, such as Gab1 Tyr-627. Furthermore, we demonstrate that EGF (i) increased the binding affinity of EGFR to Gab1 Tyr-627 and Shc Tyr-317 sites in purified GST fusion proteins approximately 4-6-fold, and (ii) EGF significantly enhanced the phosphorylation of these sites, relative to EGFR autophosphorylation, in cell lysates containing the full-length Gab1 and Shc proteins. Analysis of peptides containing amino acid substitutions indicated that residues C-terminal to the target tyrosine were critical for EGF-stimulated increases in substrate binding and regulation of kinase specificity. To our knowledge, this represents the first demonstration that ligand can alter specificity of a receptor kinase toward physiologically relevant targets.