Potential usage of ING family members in cancer diagnostics and molecular therapy

The Inhibitor of Growth (ING) gene family is an emerging putative type II tumor suppressor gene (TSG). Proteins of INGs (ING1-5), critical modulator of the histone code via PHD fingers, are able to suppress cell growth and proliferation, induce apoptosis, and modulate cell cycle progression. ING proteins are involved in transcriptional regulation of genes, such as the p53-inducible gene p21. ING proteins also serve as shuttling proteins between nucleus and cytoplasm, and dysregulation of this nucleocytoplasmic traffic has been shown in some cancer cells. In cancer cells, ING mRNA levels are often lost or suppressed but the genes are rarely mutated. Recently the potential roles of ING proteins as prognostic biomarkers, detection of aggressive behavior of the tumor as well as prediction of chemo-radiotherapy response have also emerged. In this review, we summarize the up-to-date knowledge on functions of the ING proteins, the protein status in human tumors and discuss as a potential target in the molecular diagnostics and therapy of cancer.

Assessment of atrial conduction time in patients with familial Mediterranean fever

BACKGROUND

Increased inflammatory activity is known to be a pathophysiologic characteristic of atrial fibrillation. Familial Mediterranean fever (FMF) is a disease characterized by recurrent and sustained increased inflammatory activity. Atrial conduction abnormalities in these patients have not been investigated in terms of P-wave duration, P-wave dispersion (Pd), and atrial electromechanical delay measured by tissue Doppler echocardiography (TDE). We aimed to assess atrial conduction time in patients with FMF.

METHODS

A total of 33 patients with FMF (13 males/20 females, 28.4 +/- 12.5 years), and 33 controls (13 males/20 females, 28.5 +/- 12.1 years) were included. Atrial electromechanical coupling (PA) and intra- and interatrial electromechanical delay were measured with TDE. From the 12-lead electrocardiogram Pd was calculated.

RESULTS

Atrial electromechanical coupling at the left lateral mitral annulus (PA lateral) was significantly higher in FMF patients (58.0 +/- 9.0 vs 51.0 +/- 5.8, P < 0.001). Interatrial (PA lateral-PA tricuspid) and intraatrial electromechanical delay (PA septum-PA tricuspid) were significantly longer in FMF patients (21.3 +/- 7.4 vs 12.9 +/- 4.6, P < 0.001 and 4.7 +/- 5.5 vs 2.1 +/- 1.7, P = 0.01, respectively). Also, Pd and maximum P-wave duration were significantly higher in FMF patients (42.8 +/- 7.9 vs 35.3 +/- 6.1, P < 0.001 and 98.6 +/- 9.0 vs 93.1 +/- 8.5, P = 0.01, respectively). A positive correlation was detected between interatrial electromechanical delay and Pd (r = 0.622, P < 0.001). Plasma level of C-reactive protein (CRP) correlated with interatrial electromechanical delay and Pd (r = 0.733, P < 0.001; and r = 0.427, P < 0.001, respectively).

CONCLUSION

This study shows that atrial electromechanical delay and Pd are prolonged in FMF patients. Atrial electromechanical delay is closely associated with Pd and plasma level of CRP.

T-lymphocyte maturation-associated protein gene as a candidate metastasis suppressor for head and neck squamous cell carcinomas

Previous gene expression profiles revealed the T-lymphocyte maturation-associated protein (MAL) gene as being frequently downregulated in head and neck cancer. To define the relationship between the MAL gene and the metastatic process, we evaluated the expression status of the gene in matched primary and metastatic tumors of head and neck cancer by semiquantitative reverse transcription-polymerase chain reaction. Furthermore, we aimed to identify potential genetic and epigenetic mechanisms associated with downregulation of MAL, including loss of heterozygosity (LOH), mutation, and hypermethylation. Thirty-five cell lines of University of Turko squamous cell carcinoma (UT-SCC) series derived from head and neck cancer, including nine pairs from matched primary and metastatic tumors, and 30 pairs of matched primary and metastatic tumor samples were analyzed. Twenty out of 35 (57%) cell lines showed downregulation of MAL expression, whereas no expression was found in 10 cell lines (29%). Considering matched primary and metastatic tumor-derived cell-line pairs, four pairs showed decreased expression only in metastasis-derived cells compared with their primary counterparts. Expression analysis of 21 tissue samples demonstrated decreased or no expression of MAL mRNA in 43% of metastatic tumors compared with matched primary tumors. Relating to mechanisms of downregulation, LOH was observed in 30% of primary tumors and 38% of their metastatic counterparts by a MAL-specific microsatellite marker. Furthermore, we found restoration of MAL mRNA after treatment with demethylating agent (5-aza-2'-deoxycytidine) in 9 (45%) out of 20 cell lines. No mutation was found in UT-SCC cell lines. In conclusion, our findings indicate selective downregulation of MAL expression in metastatic cells, suggesting the MAL gene as a new metastasis-suppressor candidate for head and neck cancer. LOH and hypermethylation appeared to be important mechanisms for inactivation of MAL function.

Downregulation of TESTIN and its association with cancer history and a tendency toward poor survival in head and neck squamous cell carcinoma

OBJECTIVE

To examine the role of TESTIN as a candidate tumor suppressor gene in head and neck carcinogenesis.

DESIGN

Mutation and messenger RNA (mRNA) expression analyses.

SETTING

Academic research.

PATIENTS

Paired normal and tumor samples were obtained from 38 patients with primary head and neck squamous cell carcinoma.

MAIN OUTCOME MEASURES

Analysis and comparison of TESTIN gene mRNA expression and its relationship to clinicopathologic variables.

RESULTS

Mutation analysis showed a nucleotide and amino acid change in 6 of the 38 tumor samples (16.0%). Semiquantitative mRNA expression analysis of TESTIN revealed a decreased expression in approximately 50% of the tumors compared with their matched normal controls. Interestingly, comparison of clinicopathologic variables to mRNA expression status of TESTIN revealed a significant difference in terms of cancer history (P = .03). Moreover, a higher smoking ratio and a family cancer history were also associated with downregulation of TESTIN, although the difference was not statistically significant (P = .43 and P = .16, respectively). Kaplan-Meier survival analysis demonstrated a worse survival rate among the patients with low TESTIN expression compared with the patients with normal-high TESTIN expression.

CONCLUSIONS

Our findings suggest that inactivation of TESTIN is involved in head and neck carcinogenesis through its downregulation. Further studies in various human cancer tissues using a large sample size and in vitro functional studies as well as clinical comparison research studies would give us a better evaluation of TESTIN's role and its possible future application in molecular diagnosis and treatment of different cancer types, including head and neck squamous cell carcinoma.

Secreted frizzled related protein (sFRP)-2 inhibits bone formation and promotes cell proliferation in ameloblastoma

Secreted frizzled related protein (sFRP)-2, a Wnt antagonist, was strongly expressed by both stromal and tumor cells of ameloblastoma. The aim of this study is to evaluate whether sFRP-2 secreted from tumor cells have any direct role in suppressed bone formation or not. A pre-osteoblastic cell line, KUSA/A1 cells, cultured in conditioned medium of an ameloblastoma-derived cell line (AM-1CM) was used in the study. Alkaline phosphatase (ALP) activity, alizarin red staining, mineral quantification and MTS assay was performed. Wnt-canonical pathway is a major pathway for osteoblasts. Antagonists of this pathway, sFRP-1, 2 and 3, were detected by immunohistochemistry and western blot analysis. KUSA/A1 cells cultured in AM-1CM showed high cell proliferation, low ALP activity without mineralized matrix deposition. sFRP-2 was strongly expressed in ameloblastoma tissue and AM-1 cells. After sFRP-2 depletion, the cells showed diffuse mineralization. In this study, it was confirmed that ameloblastoma cells have a major role in decreased bone formation by secreting sFRP-2 in cell culture model. Though, sFRP-2 has great effect on tumor progression, inhibition of sFRP-2's anti-bone formation activity and cell proliferative activity may reduce the invasive property of ameloblastoma and possibility of recurrence rate.

Influence of the microenvironment on gene and protein expression of odontogenic-like and osteogenic-like cells

Progenitor cells play an important biological role in tooth and bone formation, and previous analyses during bone and dentine induction have indicated that they may be a good alternative for tissue engineering. Thus, to clarify the influence of the microenvironment on protein and gene expression, MDPC-23 cells (mouse dental papilla cell line) and KUSA/A1 cells (bone marrow stromal cell line) were used, both in vitro cell culture and in intra-abdominal diffusion chambers implanted in 4-week-old male immunodefficient mice (SCID mice). Our results indicate that KUSA/A1 cells differentiated into osteoblast-like cells and induced bone tissue inside the chamber, whereas, MDPC-23 showed odontoblast-like characteristics but with a low ability to induce dentin formation. This study shows that MDPC-23 cells are especial cells, which possess morphological and functional characteristics of odontoblast-like cells expressing dentin sialophosphoprotein in vivo. In contrast, dentin sialophosphoprotein gene and protein expression was not detected in both cell lines in vitro. The intra-abdominal diffusion chamber appears as an interesting experimental model for studying phenotypic expression of dental pulp cells in vivo.

Comparison of intrathecal magnesium, fentanyl, or placebo combined with bupivacaine 0.5% for parturients undergoing elective cesarean delivery

BACKGROUND

Intrathecal (i.t.) administration of magnesium has been reported to potentiate opioid antinociception in rats and humans. In this prospective, randomized, double-blind, study, we investigated the sensory, motor, and analgesic block characteristics of i.t. magnesium 50 mg compared with fentanyl 25 microg and saline when added to 0.5% bupivacaine (10 mg).

METHODS

Ninety ASA I or II adult patients undergoing cesarean section were randomly allocated to receive 1.0 ml of 0.9% sodium chloride in group S, 50 mg of magnesium sulfate (1.0 ml) 5% in group M, or 25 microg of fentanyl (1.0 ml) in group F following 10 mg of bupivacaine 0.5% i.t. We recorded the following: onset and duration of sensory and motor block, maximal sensory block height, the time to reach the maximal dermatomal level of sensory block, and the duration of spinal anesthesia.

RESULTS

Magnesium did not shorten the onset time of sensory and motor blockade or prolong the duration of spinal anesthesia. The duration of sensory (P<0.032) and motor (P<0.002) blockade was significantly shorter in M and S groups than in the F group. The time to reach the maximal dermatomal level of sensory block was significantly shorter in the F group than in the S and M groups (P<0.002).

CONCLUSION

In patients undergoing cesarean section with spinal anesthesia, the addition of magnesium sulfate (50 mg) i.t. to 10 mg of spinal bupivacaine (0.5%) did not shorten the onset time of sensory and motor blockade or prolong the duration of spinal anesthesia, as seen with fentanyl.

Resistance to paclitaxel therapy is related with Bcl-2 expression through an estrogen receptor mediated pathway in breast cancer

Taxanes are approved for the treatment of breast cancer that has spread to the lymph nodes, following surgery and doxorubicin containing chemotherapy. Taxanes have improved the survival of breast cancer patients, especially in estrogen receptor (ER) negative population in clinical settings. This time we examined the relationship between chemosensitivity to Taxanes and expresson of ERalpha in breast cancer cell lines. In vitro effects of paclitaxel in 4 ER-positive and 3 ER-negative breast cancer cell lines were investigated by MTT assay. We also investigated members of Bcl-2 family by Western blotting and RT-PCR to clarify their role in paclitaxel resistance both in ER-positive and in ER-negative cells. ER-negative cell lines were more sensitive to paclitaxel than ER-positive cells. ER-negative KPL-4 and ZR-75-30 cells, which were sensitive to paclitaxel, became resistant when they were treated with demethylation agent, 5-aza-2'-deoxycytidine. Analysis of proapoptotic (Bax) and antiapoptotic (Bcl-2) molecules suggested that Bcl-2 is likely to have a role in the resistance of ER-positive cells. Bcl-2 expression was increased in a time-dependent manner after treatment of ER-positive cell lines with estrogen (E2). On the other hand, Bcl-2 was not detected in ER-negative cell lines. However, no significant difference was detected for Bax mRNA levels before and after E2 treatment in ER-positive and negative cell lines. Activation of ER gene expression in ER-negative KPL-4 cells by 5-aza-2'-deoxycytidine resulted in up-regulation of Bcl-2 mRNA. To support our data, we examined paclitaxel sensitivity in ER-negative MDA-MB-231 and ER stable transfectant cells S30 and JM6. This experiment also showed ER-negative cells were sensitive to paclitaxel but ER-positive cells were resistant to it. These results suggest that ER influenced chemosensitivity to paclitaxel through regulation of Bcl-2 family and regulation of the pathway may be crucial to increase the efficacy of taxanes in ER-positive breast cancer.

A spindle cell carcinoma presenting with osseous metaplasia in the gingiva: a case report with immunohistochemical analysis

BACKGROUND

Spindle cell carcinoma (SpCC) is a rare, high malignant variant of squamous cell carcinoma (SCC), which shows biphasic proliferation of conventional SCC component and malignant spindle shape cells with sarcomatous appearance.

METHODS

A case of Spindle cell carcinoma with bone-like calcified materials, occurring at the mandibular molar region of 71-years-old Japanese male patient was presented with gross finding, histological findings and MRI image. To identify the characteristics of the bone-like materials, immunohistochemistry were performed.

RESULTS

Histologically, the cancer cells were composed of spindle cells and epithelial cells which form nests with prominent keratinization. Histological findings showed typical histology of the SpCC, however, as an uncommon finding, spatters of calcified, bone-like materials were observed in between the cancer cells. Immunohistochemistry revealed that cancer cells were positive for cytokeratins and vimentin to a varying degree and negative for Desmin, S-100, Osteopontin, BMP-2 or BMP-4. These findings implied that the calcified materials were formed by metaplasia of the stromal cells.

DISCUSSION

Bone-like materials formation by osseous and/or cartilaginous metaplasia of the stroma in the carcinoma has been reported. However, the detailed mechanism of these metaplasia and affection on the clinical feature, prognosis and therapies are not well established. In summary, we presented an unique case of SpCC, which has not been described in the literature.

Sequential expressions of Notch1, Jagged2 and Math1 in molar tooth germ of mouse

The Notch signaling pathway is an evolutionary conserved mechanism that plays an important role in cell-cell communication and cell fate in a wide range of tissues. The mammalian family of Notch receptors consists of 4 members: Notch1/2/3/4. The Notch ligand family consists of 5 members: Delta1/3/4 and Jagged1/2. Math1 encodes a murine basic helix-loop-helix (bHLH) transcription factor that acts as positive regulator of cell differentiation. Recently, links between Notch and Math1 pathways were demonstrated in various tissues. Expression of Notch1, Jagged2 and Math1 were analyzed in the mouse molar tooth germ during embryonic stage (E) 13 and E15 and during postnatal stage (PN) 1, PN3, PN5, PN10 and PN14 by using in situ hybridization. Positive Notch1 expression was found at the tooth bud during embryonic stages, but its expression was absent from the basal cells in contact with the dental mesenchyme. Jagged2 and Math1 were strongly expressed in differentiated ameloblasts and odontoblasts and Math1 strong expression was even maintained until PN14 stage. Math1 showed the strongest expression. Our results suggest that the Notch1 signaling pathway through Jagged2 could be importantly related to Math1, directing the process of odontogenesis toward cell differentiation.

Frequent deletion of ING2 locus at 4q35.1 associates with advanced tumor stage in head and neck squamous cell carcinoma

BACKGROUND

Loss of heterozygosity (LOH) in the ING family members has been shown in head and neck squamous cell carcinoma (HNSCC) except for ING2. Like all the other members of ING family, ING2, which is located at chromosome 4q35.1, is a promising tumor suppressor gene (TSG). In this study, we performed LOH analysis of ING2 in HNSCC and compared it with clinicopathological variables.

MATERIALS AND METHODS

We performed LOH analysis in DNAs from 80 paired of normal and HNSCC tissues, using a specifically designed microsatellite marker on chromosome 4q35.1, which detects allelic loss of ING2. TP53 mutation analysis and its relationship with ING2 chromosomal deletion were also performed in available 68 of the samples. The correlation between LOH status and clinicopathological characteristics was evaluated by using statistical methods. The overall survival (OS) and disease free survival (DFS) were also determined.

RESULTS

LOH was detected in 54.6% (30/55) of the informative samples. Statistical significance was obtained between LOH and tumor (T) stage (P = 0.02), application of radiotherapy and chemotherapy. Positive node status (N) appeared to be the only independent prognostic factor for both OS (P = 0.031) and DFS (P = 0.044).

CONCLUSIONS

Our study showed allelic loss of 4q35.1 in HNSCC. The high percentage of LOH suggests ING2 as a candidate TSG in HNSCC. High LOH frequency was statistically associated with advanced T stage, suggesting that ING2 LOH might occur in late stages during HNSCC progression.

The inhibitor of growth (ING) gene family: potential role in cancer therapy

The discovery of ING1 gene paved the way to the identification of other ING members (ING2-5) and their isoforms associated with cell cycle, apoptosis and senescence. The ING family has been an emerging putative tumor suppressor gene (TSG) in which the major mechanism is through interaction with the determinants of chromatin function and gene-specific transcription factors. The regulatory mechanism highly involves the conserved plant homeodomain (PHD), which binds to histones in a methylation-sensitive manner, suggesting that ING proteins may contribute to the maintenance of the epigenetic code. Furthermore, ING family members contain nuclear localization signals and N-terminal sequences important in the interaction with histone acetyltransferase (HAT) and histone deacetyltransferase (HDAC) that regulate gene promoter activity within chromatin. Although ING proteins have the same PHD motif, the variation in the N-terminal dictates the differences in tumor the suppressive ability of ING in various tumors. Inactivation of the normal function is achieved through allelic loss of genomic regions containing the ING gene, alteration in the ING promoter region, variation of mRNA splicing efficacy or reduced mRNA stability. It is most probably the apparent combination of these aberrant mechanisms that resulted in reduced availability of functional ING protein. In cancer cells, ING transcript levels are often suppressed but the genes are rarely mutated. The mechanism of suppression of ING expression may have to do with the abnormally high methylation levels of the ING gene promoter, which have been correlated with low transcript levels. Emerging evidence on the function of ING and related regulatory mechanisms strongly points to ING as a candidate TSG and therefore a potential target in the molecular therapy of some types of tumor.