• Maxillofacial Plastic and Reconstructive Surgery
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• 제22권2호
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• pp.164-173
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• 2000

The p16 protein is a cyclin dependent kinase inhibitor that inhibits cell cycle progression from $G_1$ phase to S phase in cell cycle. Many p16 gene mutations have been noted in many cancer-cell lines and in some primary cancers, and alterations of p16 gene function by DNA methylation have been noticed in various kinds of cancer tissues and cell-lines. There have been a large body of literature has accumulated indicating that abnormal patterns of DNA methylation (both hypomethylation and hypermethylation) occur in a wide variety of human neoplasma and that these aberrations of DNA methylation may play an important epigenetic role in the development and progression of neoplasia. DNA methylation is a part of the inheritable epigenetic system that influences expression or silencing of genes necessary for normal differentiation and proliferation. Gene activity may be silenced by methylation of up steream regulatory regions. Reactivation is associated with demethylation. Although evidence or a high incidence of p16 alterations in a variety of cell lines and primary tumors has been reported, that has been contested by other investigators. The precise mechanisms by which abnormal methylation might contribute to carcinogenesis are still not fully elucidated, but conceivably could involve the modulation of oncogene and other important regulatory gene expression, in addition to creating areas of genetic instability, thus predisposing to mutational events causing neoplasia. There have been many variable results of studies of head and neck squamous cell carcinoma(HNSCC). This investigation was studied on 13 primary HNSCC for p16 gene status by protein expression in immunohistochemistry, and DNA genetic/epigenetic analyzed to determine the incidence, the mechanisms, and the potential biological significance of its Inactivation. As methylation detection method of p16 gene, the methylation specific PCR(MSP) is sensitive and specific for methylation of any block of CpG sites in a CpG islands using bisulfite-modified DNA. The genomic DNA is modified by treatment with sodium bisulfate, which converts all unmethylated cytosines to uracil(thymidine). The primers designed for MSP were chosen for regions containing frequent cytosines (to distinguish unmodified from modified DNA), and CpG pairs near the 5' end of the primers (to provide maximal discrimination in the PCR between methylated and unmethylated DNA). The two strands of DNA are no longer complementary after bisulfite treatment, primers can be designed for either modified strand. In this study, 13 paraffin embedded block tissues were used, so the fragment of DNA to be amplified was intentionally small, to allow the assessment of methylation pattern in a limited region and to facilitate the application of this technique to samlples. In this 13 primary HNSCC tissues, there was no methylation of p16 promoter gene (detected by MSP and automatic sequencing). The p16 protein-specific immunohistochemical staining was performed on 13 paraffin embedded primary HNSCC tissue samples. Twelve cases among the 13 showed altered expression of p16 proteins (negative expression). In this study, The author suggested that low expression of p16 protein may play an important role in human HNSCC, and this study suggested that many kinds of genetic mechanisms including DNA methylation may play the role in carcinogenesis.

• Journal of Gastric Cancer
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• 제5권3호
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• pp.200-205
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• 2005

목적: Zinc finger를 가진 KLF4는 위장관 상피세포의 항상성 유지에 중요한 역할을 하는 종양억제유전자이다. 연구자들은 KLF4 단백의 발현 변화가 위암의 발생에 관여하는지를 파악하고 위암의 병리 지표들과 연관성이 있는지를 알아보고자 하였다. 대상 및 방법: 84예의 파라핀 포매된 위암조직에서 암세포들을 각각 3군데에서 펀치하여 새로운 파라핀 블록으로 옮겨 위암의 tissue microarray를 제작하였다. Tissue microarray 절편에서 KLF4 단백에 대한 항체로 면역화학염색을 실시한 후 발현 양상을 병리 지표들인 조직학적 소견, 침습 정도, 림프절 전이 및 복막파종 등과의 연관성을 조사하였다. 결과: KLF4 단백은 위점막의 표면과 소와 상피세포의 세포질과 핵에서 주로 발현되고 있었고 조사된 위암 84예 중 43예(51.2%)에서 발현이 현저히 저하되어 있거나 소실되어 있었다. 이러한 KLF4 단백의 발현 소실은 조직학적 소견, 침습 정도, 림프절 전이 및 복막파종과는 통계적으로 연관성이 없었다. 결론: 이러한 연구 결과는 KLF4 단백의 발현 소실이 위장관 상피세포의 비정상적인 성장과 분화를 유도하고 위암의 발생 초기에 관여한다는 것을 의미한다.

• 치과방사선
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• 제21권2호
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• pp.203-220
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• 1991

The purpose of this study was to investigate the changes of morphology and structure of bone tissue, caused by administration of high-dose hydrocortisone, elcatonin and cyclophosphamide. In order to carry out experiment, 60 four-week old Sprague-Dawley strain rats weighing about 107 gms were selected and divided into experimental group and control group. The experimental group was subdivided into three groups, assigned fifteen rats for each group, by the different drugs administered. Each experimental group was then categorized as follows: hydrocortisone 30㎎/㎏ b.w. with daily subcutaneous injection, elcatonin 20U/㎏ b.w. with daily subcutaneous injection, and cyclophosphamide 100㎎/㎏ b.w. with a single intraperitoneal injection. Fifteen rats were injected daily with 5㎖/㎏ b.w. of normal saline solution subcutaneously in control group. Rats in control group and experimental group were serially sacrificed on the 6th, the 15th and the 22nd day after injection of normal saline, hydrocortisone, elcatonin and cyclophosphamide, respectively. Being sacrificed, both sides of mandibular condyles were removed and fixed with 10% neutral formaline. The one side of mandibular condyles was radiographed with soft X-ray apparatus. Thereafter, the obtained radiographs were observed, and the bone density of condylar head and condylar neck regions was measured by use of transferring video-based digital radiograph. The other side was further decalcified and embedded in paraffin as usual manner, then sectioned and stained with hematoxylin and eosin, observed by light microscope. The obtained results were as follows: 1. Sclerotic changes with regularly increased trabecular pattern were seen throughout experimental periods in hydrocortisone group. Increased the number of trabecular pattern with irregularity and periodic striation on the periphery of condylar head region were appeared with lapse of time in elcatonin group. In cyclophosphamide group, irregular trabecular pattern and stippled radiopacities on mandibular condyle were observed with lapse of time. 2. The bone density of condylar head region was increased in hydrocortisone group, decreased in elcatonin group, and tended to be decreased in cyclophosphamide group, compared with that of control group according to the experimental periods. 3. The bone density of condylar neck region tended to be rather increased in hydrocortisone group, elcatonin group and cyclophosphamide group, depending on the experimental periods. 4. In microscopic studies, there were irregular trabecular bonds and osteoblastic activity in hydrocortisone group and elcatonin group throughout experimental periods, degenerative cartilage and trabecular bones in the 6th day and densely calcified trabecular bones in the 22nd day in cyclophosphamide group.

• 치과방사선
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• 제22권2호
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• pp.241-252
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• 1992

The purpose of this study was to investigate the changes of morphology and structure of bone tissue in the irradiated mandibular bone in rats which were fed a low calcium diet. In order to carry out this experimant, 64 seven-week old Sprague-Dawley strain rats weighing about 150gms were selected and equally divided into one experimental group of 32 rats and one control group with the remainder. The experimental group and the control group were then subdivided into two groups when the rats reached ten-week old, 16 were assigned rats for each subdivided group, exposed to irradiation. The two irradiation groups received a single dose of 20 Gy in the jaws area only and irradiated with a cobalt-60 teletherapy unit. The rats in the control and experimental groups were serially terminated by fours on the 3rd, the 7th, the 14th, and the 21st day after irradiation. Following termination, both sides of the dead rats mandibular bodies were removed and fixed with 10% neutral formalin. One side of the mandibular body was radiographed with a soft X-ray apparatus. Thereafter, the obtained microradiographs were observed by a light microscope. The remaining side of the mandibular bone was further decalcified and embedded in paraffin as using the general method. The specimen sectioned and stained with hematoxylin and eosin, and Rabit Anti-Human Tumor Necrosis Factor-a, observed by a light microscope. The obtained results were as follows: 1. Microradiogram revealed that thinning of the cortex and a decrease in the trabecula of the interradicular bone and mandibular body were observed and noted from the start to finish throughout the experiment in the non-irradiated rats on the low calcium diet rather than in the non-irradiated rats on the normal diet. In microscopic observations, there were marked osteolytic changes in the center of the bone marrow. 2. Microradiogram revealed that thinning of the cortex and a decrease in the trabecula of interradicular bone and mandibular body were more marked after 7 days in the irradiated rats on the low calcium diet rather than in the non-irradiated rats on the low clacium diet. In microscopic observations, osteoblasts were decreased markedly after 7 days, and a few osteoclasts were observed. 3. Microradiogram revealed that thinning of the cortex and a decrease in trabecula of interradicular bone and the mandibular body were more marked from the strart to finish troughout the experiment in the irradiated rats on the low calcium diet rather than in the irradiated rats on the normal diet. In microscopic observations, there were no osteolytic changes noted in the irradiated rats on the normal diet. 4. In immunocytochemical findings, a few bone marrow cells including Tumor Necrosis Factor were observed in the irradiated rats on the normal diet, but was not observed in the rats on the low calcium diet.

• Asian Pacific Journal of Cancer Prevention
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• 제15권9호
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• pp.4061-4065
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• 2014

The presence of viral DNA in breast cancer cells is controversial. However, some studies have revealed a possible role for the human papillomavirus in the pathogenesis of breast cancer. The aim of the present study was to investigate the presence of HPV-DNA in breast tissue in a group of Iranian women with and without breast cancer and identification of the detected HPV types. Paraffin-embedded specimens from 65 malignant breast cancer cases and 65 cases with benign breast lesions were investigated for presence of HPV-DNA by nested polymerase chain reaction. We found HPV-DNA in 22 (33.8%) of the breast cancer specimens. All non-cancerous specimens were negative. Low and high-risk HPV types, including HPV-6 (26.2%), HPV-16 (1.5%), HPV-35 (1.5%), HPV-52 (1.5%), and HPV-11 (1.5%) were detected in our study. HPV-6 was the most prevalent type in the breast cancer specimens. Although high-risk HPV types have been shown to have a major role in cervix cancer, there have been no data that support the same relevance for other types of malignancies. Furthermore, presence of low-risk HPV types in malignancies still is a matter of debate. The data presented in this study indicates a strong need for epidemiological studies correlating different HPV types in human breast cancer.

• Journal of Gastric Cancer
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• 제2권3호
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• pp.151-156
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• 2002

Purpose: The prognosis of gastric cancer depends on the depth of invasion, lymph-node metastasis, invasion to adjacent tissues, and distant metastasis. Recently, it is known that tumor-associated proteases and adhesion molecules have been shown to play a relevant role in the process of progression and metastasis. The purpose of our study was to demonstrate the value of MMP-2 (matrix metalloproteinase), cathepsin D and E-cadherin as prognostic factors. Materials and Methods: In this study, formalin-fixed, paraffin-embedded tissue blocks from 69 patients with gastric cancer were immunohistochemically studied using antibodies to MMP-2, cathepsin D, and E-cadherin, and their expressions were analyzed according to the pathologic stage, lymph-node metastasis, histological differentiation, and patient survival. The medical records of these patients were retrospectively reviewed. Results: Increased expression of MMP-2 significantly correlated with advanced pathologic stage (P=0.026). Patients with lymph-node metastasis also had increased expression of MMP-2. Those patients with increased expression of MMP-2 showed a poorer survival; nevertheless, it was not statistically significant. Increased expression of cathepsin D significantly correlated with advanced pathologic stage (p=0.029). However, no correlation was observed between advanced pathologic stage and either lymph-node status or histological differentiation. Patients with increased expression of cathepsin D had a poorer survival, but that result was not statistically significant. No association was found between reduced expression of E-cadherin and pathologic stage, lymph-node status, or histological differentiation. Also, no correlation was found between the expression of E-cadherin and survival. In addition, when a combination of MMP-2 and cathepsin D expressions was analyzed, if both were negative, the survival seems to be longer, but it was not statistically significant. Conclusions: In patients with gastric cancer, expressions of MMP-2 and cathepsin D correlated with tumor stage; therefore, they may be considered as prognostic factors.

• 대한골관절종양학회지
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• 제5권3호
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• pp.162-168
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• 1999

c-fos와 c-jun은 암 유전자의 하나이며, 이 유전자의 단백질 산물은 여러 가지의 다른 활성화 단백 (activator protein 1, AP-1)으로 골 종양에서 골세포의 증식과 분화를 조절하는 중요한 역할을 하는 인자 중 하나로 알려져 있다. 본 연구에서는 단클론 항체를 이용하여 포르말린에 고정된 파라핀 포매조직을 이용하여 35례의 사람 골육종에서 c-fos 단백의 발현을 연구하였다. c-fos의 발현은 골 형성 병변에서 주로 발현되며, 저등급의 연골형성 병변에서는 발현이 관찰되지 않았다. 높은 빈도의 c-fos 단백의 발현이 골아성 골육종에서 발현되었으나 (17례 중 13례에서 1등급 내지 2등급으로 발현), 2례의 연골형성 골육종, 1례의 섬유아세포성 골육종, 2례의 방골성 골육종에서는 음성으로 나타났다. 2례의 혈관확장성 골육종에서는 양성으로 c-fos 단백의 발현되었다. 비록 조직학적으로 고등급의 골육종에서 면역조직화학적 염색상 고 빈도의 c-fos 단백의 발현이 관찰되나, 조직학적 등급과, 면역염색상 발현사이에 통계적인 유의성은 관찰되지 않았다. 이상의 결과로 c-fos 단백이 골육종의 발생에 관여할 것으로 추론되며, 저등급의 연골형성 육종에 이 단백의 역할에는 추후 연구가 필요할 것으로 사료된다.

• 대한수의학회지
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• 제41권4호
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• pp.467-475
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• 2001

Cardiac arrest, hypoxia, shock or seizure has been known to induce cerebral ischemia. This study was designed to investigate the effect of ischemia on hippocampal pyramidal layer induced by transient bilateral occlusion of the common carotid arteries. Mature Mongolian gerbils were sacrificed at days 2, 4, and 7 after carotid occlusion for 10 minutes. Sham-operated gerbils of control group were subjected to the same protocol except for carotid occlusion. During operation for ischemia, body temperature was maintained $37{\pm}0.5^{\circ}C$ in all gerbils. Paraffin-embedded brain tissue blocks were cut into coronal slices and stained with H-E stain or immunostain by TUNEL method. Neurons with the oval and prominent nucleus and without the eosinophilic cytoplasm in the subfield of hippocamapal pyramidal layer were calculated as to be viable neurons. Their chromatins were condensed or clumped. Their nuclei appeared multiangular or irregularly shrinked. The width of the pyramidal layer was reduced due to the loss of nuclei. At day 2 after reperfusion, some neurons in the CA1 subfield were slightly eosinophilic. But most neurons in the CA2 subfield were strongly eosinophilic. At day 4 day, most neurons in the CA1 subfield were severely damaged and at day 7 day, only a few survived neurons were observed. Survived neurons per longitudinal 1mm sector in the CA1, CA2, CA3, and CA4 subfields of pyramidal layer were investigated. At day 2, the mean numbers of pyramidal neurons in CA1, CA2, CA3, and CA4 subfiedls were 104.5/mm (54.3%), 51.0/mm (33.8%), 105.5/mm (85.6%), and 124.3/mm (93.5%) compared to the nonischemic control group, respectively. At day 4, the mean numbers of pyramidal neurons in CA1, CA2, CA3, and CA4 subfields were 3.2/mm (1.7%), 51.5/mm(34.2%), 95.3/mm (77.4%), and 112.5/mm (84.6%), respectively. At day 7, the mean numbers of pyramidal neurons in CA1, CA2, CA3, and CA4 subfiedls were 0.8/mm (0.4%), 5.7/mm(3.8%), 9.8/mm (8.0%), and 5.0/mm (3.7%), respectively. The mean numbers of apoptotic positive neurons in the CA1 subfield at day 2, 4, and 7 after reperfusion were 67.8/mm, 153.2/mm and 123.7/mm, respectively. These results suggest that the transient cerebral ischemia cause severe damages in most neurons at day 7 and that the prosminent apoptotic positive neurons in hippocampal pyramidal layer are the delayed neuronal death induced by ischemia.

• Asian Pacific Journal of Cancer Prevention
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• 제15권1호
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• pp.369-374
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• 2014

Background: Colorectal cancer (CRC) is the fourth most common cause of cancer death in the world. Genetic variants in 8q24.21 including rs10505477 and rs6983267 have been hypothesized to be involved in susceptibility to CRC. This study aims to investigate the possible association between these loci and their haplotypes with CRC risk in Iranian population. Materials and Methods: Subjects were recruited from two hospitals in Tehran. The rs10505477 and rs6983267 polymorphisms were genotyped by TaqMan real time PCR using subject genomic DNA, extracted either from formalin-fixed, paraffin-embedded tissue of patients or from blood of the controls by standard methods. Results: A total of 715 subjects (380 CRC patients and 335 matched controls) were genotyped in this study. Allele and genotype analysis of the rs10505477 and rs6983267 polymorphisms by gender, age at diagnosis, tumor location, tumor grade, and tumor node metastasis (TNM) showed no significant association with CRC risk. There was a significant relationship between GG haplotype and susceptibility to age at diagnosis for both <60 and ${\geq}60$ (p=0.0005 and p=0.000004, respectively) and between GT and CRC in the age at diagnosis ${\geq}60$ (Table 3: p=0.031). The GG haplotype was less frequent in CRC patients with the age at diagnosis <60, but was more common in subjects with the age at diagnosis ${\geq}60$. Conclusions: Results of this study suggests that the rs6983267 and rs10505477 polymorphisms alone may not be relevant to CRC risk, but their GG haplotype plays a notable role in age at diagnosis of CRC in the Iranian population.

• 폴리머
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• 제30권3호
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• pp.196-201
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• 2006

온도감응성 고분자인 폴리 (에틸렌 글리콜)을 기본으로 하는 다이블록 및 트리블록 폴리에스테르 공중합체들은 비독성과 생체적합성 그리고 생분해성 특징 때문에 조직공학 분야 및 주사제형의 약물전달체에서 많은 응용이 이루어지고 있다. 본 연구에서는 다이블록 공중합체를 이용한 솔-젤 전이 현상을 갖는 고분자를 평균분자량 750 g/mole의 메톡시 폴리 (에틸렌 글리콜)과 카프로락톤을 실온에서 HCl $Et_2O$ 존재 하에서 개환중합을 통하여 합성하였다. 이 공중합체를 이용하여 in vivo상에서 골수간엽줄기세포와 골유도물질인 덱사메타손의 존재 여부에 따라 골분화의 가능성을 조사하였다. 조직을 파라핀으로 고정시켜 슬라이드를 제조한 후 hematoxylin & eosin, 본쿠사 및 오스테오칼신 염색을 통하여 골형성 정도를 확인하였다. 결론적으로 덱사메타손이 함유된 젤이 골형성에 도움을 주지만 젤만으로는 강한 골형성을 유도할 수 없으므로 줄기세포나 다른 골형성 유도재료를 사용하면 우수하게 골형성 효과를 가져올 것이라고 판단되었다.