• IMMUNE NETWORK
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• 제12권4호
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• pp.155-164
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• 2012

It is well established that blocking the interaction of EGFR with growth factors leads to the arrest of tumor growth, resulting in tumor cell death. ER414 is a human monoclonal antibody (mAb) derived by guided selection of the mouse mAb A13. The ER414 exhibited a ~17-fold lower affinity and, as a result, lower efficacy of inhibition of the EGF-mediated tyrosine phosphorylation of EGFR when compared with mAb A13 and cetuximab. We performed a stepwise in vitro affinity maturation to improve the affinity of ER414. We obtained a 3D model of ER414 to identify the amino acids in the CDRs that needed to be mutated. Clones were selected from the phage library with randomized amino acids in the CDRs and substitution of amino acids in the HCDR3 and LCDR1 of ER414 led to improved affinity. A clone, H3-14, with a ~20-fold increased affinity, was selected from the HCDR3 randomized library. Then three clones, ER2, ER78 and ER79, were selected from the LCDR1 randomized library based on the H3-14 but did not show further increased affinities compared to that of H3-14. Of the three, ER2 was chosen for further characterization due to its better expression than others. We successfully performed affinity maturation of ER414 and obtained antibodies with a similar affinity as cetuximab. And antibody from an affinity maturation inhibits the EGF-mediated tyrosine phosphorylation of EGFR in a manner similar to cetuximab.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권2호
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• pp.97-108
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• 2011

Cancer stem cells have stem cell-like features, such as the ability for self-renewal and differentiation but show unlimited growth because they have the lost normal regulation of cell growth. Cancer stem cells and normal stem cells have similar features. They show high motility, diversity of progeny, robust proliferative potential, association with blood vessels, immature expression profiles, nestin expression, epidermal growth factor (EGF)-receptor expression, phosphatase and tensin homolog (PTEN) expression, hedgehog pathway activity, telomerase activity, and Wnt pathway activity. On the other hand, with cancer cells, some of these signaling pathways are abnormally modified. In 1875, Cohnheim suggested the concept of cancer stem cells. Recently, evidence for the existence of cancer stem cells was identified. In 1994, the cancer stem cells' specific cell surface marker for leukemia was identified. Since then, other specific cell surface markers for cancer stem cells in solid tumors (e.g. breast and colon cancer) have been identified. In oral cancer, studies on cancer stem cells have been performed mainly with squamous cell carcinomas. Oral cancer specific cell surface markers, which are genes strongly expressed in oral cancer and cancer stem cell specific side populations, have been identified. Cancer stem cells are resistant to radiotherapy and chemotherapy. Therefore, to eliminate malignant tumors efficiently and reduce the recurrence rate, therapy targeting cancer stem cells needs to be performed. Currently, studies targeting the cancer stem cells' specific signaling pathways, telomerase and tumor vasculatures are being done.

• 대한종양외과학회지
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• 제14권2호
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• pp.89-94
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• 2018

Purpose: To investigate the relationship between MUC expression and clinicopathologic factors in advanced gastric cancer. Methods: A total of 237 tumor specimens were assessed for MUC expression by immunohistochemistry. The clinicopathologic factors were investigated with MUC1, MUC2, MUC5AC, and MUC6. Results: MUC1, MUC2, MUC5AC, and MUC6 expression was identified in 148 of 237 (62.4%), 141 of 237 (59.5%), 186 of 237 (78.5%), and 146 of 237 (61.6%) specimens, respectively. MUC1 expression was correlated with age, human epidermal growth factor receptor 2 (HER2) status, lymphatic invasion, Lauren classification and histology. Further multivariate logistic regression analysis revealed a significant correlation between MUC1expression and lymphatic invasion, diffuse type of Lauren classification. MUC5AC expression was correlated with HER2 status, Lauren classification and histology. Further multivariate logistic regression analysis revealed a significant correlation between MUC5AC expression and HER2 status, diffuse and mixed type of Lauren classification. MUC2 and MUC6 expression were not correlated with clinicopathologic factors. The patients of MUC1 expression had poorer survival than those without MUC1 expression, but MUC2, MUC5AC or MUC6 were not related to survival. In an additional multivariate analysis that used the Cox proportional hazards model, MUC1 expression was not significantly correlated with patient survival independent of age, N-stage, and venous invasion. Conclusion: When each of these four MUCs expression is evaluated, in light of clinicopathologic factors, MUC1 expression may be considered as a prognostic factor in patients with advanced gastric cancer. Therefore, careful follow-up may be necessary because the prognosis is poor when MUC1 expression is present.

• Journal of Breast Cancer
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• 제21권4호
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• pp.415-424
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• 2018

Purpose: Triple-positive breast cancer is defined by estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2) positivity. Several systemic breast cancer therapies target hormonal and HER2 responsiveness. We compared clinical outcomes of triple-positive disease with those of HER2-enriched and luminal HER2-negative disease and investigated the clinical efficacy of anti-HER2 therapy for triple-positive disease. Methods: We retrospectively compared overall and recurrence-free survival among cases included in the Korean Breast Cancer Society (KBCS) and Seoul St. Mary's Hospital breast cancer registries and the therapeutic efficacy of trastuzumab for triple-positive and HER2-enriched cases. Results: KBCS registry data (2006-2010; median follow-up, 76 months) indicated that patients with triple-positive breast cancer had intermediate survival between those with luminal A and HER2-enriched subtypes (p<0.001). Trastuzumab did not improve overall survival among patients with triple-positive breast cancer (p=0.899) in contrast to the HER2-enriched subtype (p=0.018). Seoul St. Mary's Hospital registry data indicated similar recurrence-free survival outcomes (p<0.001) and a lack of improvement with trastuzumab among patients with triple-positive breast cancer (median follow-up, 33 months; p=0.800). Multivariate analysis revealed that patients with triple-positive breast cancer had better overall survival than those with HER2-enriched disease and similar survival as those with the luminal A subtype (triple-positive: hazard ratio, 1.258, p=0.118; HER2-enriched: hazard ratio, 2.377, p<0.001). Conclusion: Our findings showed that anti-HER2 therapy was less beneficial for treatment of triple-positive breast cancer than for HER2-enriched subtypes of breast cancer, and the triple-positive subtype had a distinct prognosis.

• Asian Pacific Journal of Cancer Prevention
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• 제15권6호
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• pp.2753-2758
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• 2014

Background: GC-binding factor 2 (GCF2) is a transcriptional regulator that represses transcriptional activity of the epidermal growth factor receptor (EGFR) by binding to a specific GC-rich sequence in the EGFR gene promoter. In addition to this function, GCF2 has also been identified as a tumor-associated antigen and regarded as a potentially valuable serum biomarker for early human hepatocellular carcinoma (HCC) diagnosis. GCF2 is high expressed in most HCC tissues and cell lines including HepG2. This study focused on the influence of GCF2 on cell proliferation and apoptosis in HepG2 cells. Materials and Methods: GCF2 expression at both mRNA and protein levels in HepG2 cells was detected with reverse transcription (RT) PCR and Western blotting, respectively. RNA interference (RNAi) technology was used to knock down GCF2 mRNA and protein expression. Afterwards, cell viability was analyzed with a Cell Counting Kit-8 (CCK-8), and cell apoptosis and caspase 3 activity by flow cytometry and with a Caspase 3 Activity Kit, respectively. Results: Specific down-regulation of GCF2 expression caused cell growth inhibition, and increased apoptosis and caspase 3 activity in HepG2 cells. Conclusions: These primary results suggest that GCF2 may influence cell proliferation and apoptosis in HepG2 cells, and also provides a molecular basis for further investigation into the possible mechanism at proliferation and apoptosis in HCC.

• Journal of Breast Disease
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• 제6권2호
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• pp.52-59
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• 2018

Purpose: This study aimed to determine whether clinicopathological factors are potentially associated with successful breast-conserving surgery (BCS) after neoadjuvant chemotherapy (NAC) and develop a nomogram for predicting successful BCS candidates, focusing on those who are diagnosed with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative tumors during the pre-NAC period. Methods: The training cohort included 239 patients with an HR-positive, HER2-negative tumor (${\geq}3cm$), and all of these patients had received NAC. Patients were excluded if they met any of the following criteria: diffuse, suspicious, malignant microcalcification (extent >4 cm); multicentric or multifocal breast cancer; inflammatory breast cancer; distant metastases at the time of diagnosis; excisional biopsy prior to NAC; and bilateral breast cancer. Multivariate logistic regression analysis was conducted to evaluate the possible predictors of BCS eligibility after NAC, and the regression model was used to develop the predicting nomogram. This nomogram was built using the training cohort (n=239) and was later validated with an independent validation cohort (n=123). Results: Small tumor size (p<0.001) at initial diagnosis, long distance from the nipple (p=0.002), high body mass index (p=0.001), and weak positivity for progesterone receptor (p=0.037) were found to be four independent predictors of an increased probability of BCS after NAC; further, these variables were used as covariates in developing the nomogram. For the training and validation cohorts, the areas under the receiver operating characteristic curve were 0.833 and 0.786, respectively; these values demonstrate the potential predictive power of this nomogram. Conclusion: This study established a new nomogram to predict successful BCS in patients with HR-positive, HER2-negative breast cancer. Given that chemotherapy is an option with unreliable outcomes for this subtype, this nomogram may be used to select patients for NAC followed by successful BCS.

• 한국수정란이식학회지
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• 제33권4호
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• pp.287-296
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• 2018

Ganglioside GM3 is known as an inhibition factor of cell differentiation and proliferation via inhibition of epidermal growth factor receptor (EGFR) phosphorylation. Our previous study showed that the exogenous ganglioside GM3 reduced the meiotic maturation of porcine oocytes and induced apoptosis at 44 h of in vitro maturation (IVM). However, the role of ganglioside GM3 in the relationship between EGFR signaling and apoptosis during porcine oocyte maturation has not yet been studied. First, porcine cumulus-oocyte complexes (COCs) were cultured in the NCSU-23 medium with exogenous ganglioside GM3 according to maturation periods (non-treated, only IVM I: 0 - 22 h, only IVM II: 22 - 44 h and IVM I & II: 0 - 44 h). We confirmed that the proportion of germinal vesicle breakdown (GVBD) increased significantly in the IVM I treated group than in the control group. We also confirmed that the meiotic maturation until M II stage and polar body formation decreased significantly in the only IVM I treated group. Cumulus cell expansion and mRNA levels of the expansion-related factors (HAS2, TNFAIP6 and PTX3) decreased significantly in the IVM I treated group than in the control group. Protein levels of EGFR, p-EGFR, ERK1/2, and p-ERK1/2 decreased significantly in the GM3-treated groups, during the IVM I period. In addition, cellular apoptosis, determined using TUNEL assay, and protein levels of Cleaved caspase 3, were increased significantly in the GM3-treated COCs during the IVM I period. Based on these results, ganglioside GM3 exposure of porcine COCs during the IVM I period reduced meiotic maturation and cumulus cell expansion via inhibition of EGFR activity in pigs.

• Journal of Chest Surgery
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• 제31권4호
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• pp.362-368
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• 1998

편평세포폐암 환자 혈청내 SCC항원(squamous cell carcinoma antigen)의 암표지자로서의 유용성을 검정하고 암종이 성장함으로써 정상조직으로 침범하는 기전을 규명하기 위하여 폐암수술후 절제해 낸 폐암조직의 중심부와 말초부 그리고 암세포가 없는 정상 폐조직을 채취하여 SCC항원 농도와 DNA합성을 통해 세포성장과 분화에 관련이 있는 것으로 알려진 EGFr(epidermal growth factor receptor)의 농도를 측정하였다. 편평세포폐암종 조직내 SCC항원의 농도는 69＋25 ng/ml로 정상 폐조직 34＋7 ng/ml, 폐선암 35＋25 ng/ml보다 높았으며(p<0.05), EGFr의 농도는 폐암조직, 즉 편평세포암 47＋6 pmol/min, 선암 69＋20 pmol/min으로 정상 폐조직 34＋5 pmol/min, 39＋8 pmol/min보다 각각 높게는 나타났으나 유의성은 없었다. 암종의 크기에 따른 부위별 SCC항원의 농도는 암종이 직경이 3cm이하인 경우는 암종의 중심부(100＋82 ng/ml)가 말초부(55＋24 ng/ml)보다 높게 나타났으나(p>0.05), 5cm이상인 경우는 암종의 말초부(324＋92 ng/ml)가 중심부(34＋18 ng/ml)보다 현저히 높았다.(p<0.05) 그러나 부위별 EGFr의 농도는 암종의 크기에 따라 차이가 없었다. 암병기에 따른 부위별 SCC항원의 농도는 암중심부에서는 1, 2병기에서 3, 4병기로 암병기가 높아짐에 따라 감소하는 경향을 보였으나 통계적 유의성은 없었고(p>0.05), 암말초부에서는 1, 2병기 68＋37 ng/ml, 87＋35 ng/ml에서 3,4병기414＋87 ng/ml, 473＋226 ng/ml로 병기가 높아짐에 따라 현저하게 증가하였다.(p<0.05) 그러나 EGFr은 암중심부에서 1병기에서 2, 3, 4병기로 병기가 높아짐에 따라 증가하는 경향을 보였으나 통계적 유의성이 없었고(p<0.05), 암말초부에서는 병기에 따른 농도의 특이한 변화를 관찰할 수 없었다. 이상의 결과로 편평세포폐암종 조직내 SCC항원의 농도는 정상 폐조직이나 폐선암조직에서 보다 높게 나타나 혈청내 SCC항원의 농도가 편평세포폐암의 진단 및 치료효과를 예측하는데 유용한 암표지자로 생각되나, 암종내 부위별 SCC항원의 농도와 EGFr의 농도가 일치하지 않음으로써 암종이 성장함으로써 주위조직으로의 침범과 SCC항원의 농도와의 관계에 대해서는 보다 더 많은 연구가 필요할 것으로 사료된다.

• Journal of Chest Surgery
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• 제43권6호
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• pp.588-595
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• 2010

배경: 종양의 종류에 따라 발현되는 종양 항원의 종류도 다양하며 그 발현률의 차이는 더욱 다양하다. 이와 같은 이유로 폐암의 치료연구를 위해서는 인체를 대신할 만한 동물 모형이 절대 필요하다. 저자는 편평상피세포암의 세포주를 배양하여 Nude mice의 흉강 내에 주입하는 방법으로 종양형성을 시도하여 종양형성의 성공 유무와 조직학적 변화와 함께 폐암과 관련 있는 EGFR (epidermal growth factor receptor)의 수용기 중 하나인 HER2/neu 종양 유전자와 세포 성장 억제 작용과 악성화 과정에서의 저항성으로 작용하는 TGF-${\beta}_1$을 각각 정량 하도록 하여 인공적인 동소 폐암의 경우 암유전자의 발현에 관하여 조사해보고자 하였다. 대상 및 방법: 면역성이 없는 20마리의 수컷생쥐 (Male BALB/c nude mice)로 5마리를 대조군으로 하였으며, 나머지 15마리는 실험군으로 하고 체중은 20~25 gm (Orient, Japan)의 범위에 있었다. HER2/neu는 채혈하여 보관된 혈액의 혈청을 분리하여 CLIA (chemiluminiscent immunoassay) 법으로 정량적으로 측정하였으며 TGF-${\beta}_1$은 immunosandwitch법을 이용하여 정량 분석하였다. 통계학적 분석을 위하여 SPSS통계(SPSS Version10.0, USA)프로그램을 이용하였으며 Student T test를 하였으며 p값이 0.05 미만인 경우를 유의성이 있는 것으로 간주하였다. 결과: 정상 대조군에서나 인위적으로 주입한 폐암 세포주에 의한 폐암이 만들어진 이후에도 HER2/neu 유전자의 증폭은 전혀 반응을 나타내지 못하였다. 하지만 TGF-${\beta}_1$ 대조군의 정량치는 $28,490{\pm}8,549pg/mL$이었고 폐암 세포 주입군은 $42,362{\pm}14,449pg/mL$로 유의하게 1.48배 높게 나왔다(p<0.483). HER2/neu 유전자와 TGF-${\beta}_1$은 유의한 상관관계가 없는 것으로 나타났다. 결론: TGF-${\beta}_1$유전자는 대조군에 비하여 1.48배 정도의 증폭이 발현되었다. TGF-${\beta}_1$의 증폭은 Nude mice에서 발암에 의한 생체 치유 억제 기전이 확실히 작동하고 있다는 것을 의미하며, 인체의 조기 폐암의 발견에 역할을 가능케 하는 정량 검사법으로 이용할 수도 있을 것이다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권14호
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• pp.5539-5544
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• 2014

Background: To evaluate the location of tumor relapse and imaging modality for detection according to the breast cancer subtype: luminal A, luminal B, HER2 positive luminal B, nonluminal HER2 positive, and triple negative. Materials and Methods: A total of 1244 patients with breast cancer with known estrogen receptor (ER), progesterone receptor (PR), Ki-67 and human epidermal growth factor receptor 2 (HER2), who underwent breast surgery from 2009 to 2012 were analyzed. Patients were classified into the following categories: luminal A (n=458), luminal B (n=241), HER2 positive luminal B (n=227), nonluminal HER2 positive (n=145) and triple negative (n=173). A total of 105 cases of relapse were detected in 102 patients: locoregional recurrence (n=46), recurrence in the contralateral breast (n=28) and distant metastasis (n=31). Comparison of proportions was used to determine the difference between subtypes. Results: Relapse rates by subtypes are as follows: luminal A 23 of 458 (5.02%), luminal B 19 of 241(7.88%), HER2 positive luminal B 15 of 227 (6.61%), nonluminal HER2 postive 19 of 145 (13.10%) and triple negative 29 of 173(16.76%). Luminal A tumors had the lowest rate of recurrence and had significantly lower recurrence rate in comparison with nonluminal HER2 postive (p=0.0017) and triple negative subtypes (p<0.0001). Compared with all other subtypes except nonluminal HER2 positive, triple negative tumors had the highest rate of tumor recurrence (p<0.01). Triple negatives were most likely to develop contralateral recurrence against all subtypes (p<0.05). Detection rate of locoregional and contralateral tumor recurrence were 28.3% on mammography (n=17/60). Conclusions: Luminal A tumors are associated with a low risk of recurrence while triple negative lesions have a high risk. In case of triple negative tumors, the contralateral breast has much more recurrence as compared with all other subtype. In terms of detection rates, breast USG was the best modality for detecting tumor recurrence, compared with other modalities (p<0.05). Subtyping of breast tumors using a molecular gene expression panel can identify patients who have increased risk of recurrence and allow prediction of locations of tumor recurrence for each subtype.