Invasive non-native species are one of the main threats to biodiversity. Recently, more than 30 non-native species were reported to have established in the four major rivers of South Korea, and introduction of non-native species is gradually accelerating. However, ecological information necessary for prevention and management of non-native species introductions and consequent spread is lacking in South Korea, and especially so for freshwater non-native species. In this study, we assessed eight non-native freshwater fishes established in the Geum River watershed [the Risk Assessment (RA) area] using the Aquatic Species Invasiveness Screening Kit (AS-ISK). Receiver operating curve analysis identified threshold values of 24.75 for the BRA (Basic Risk Assessment) and 35.75 for the BRA+CCA (BRA + Climate Change Assessment). Four species, namely Carassius cuvieri, Lepomis macrochirus, Micropterus salmoides and Oreochromis niloticus were ranked as ‘high risk’; whereas, the lowest scoring non-native species was Coreoperca kawamebari, which is not likely to be invasive in the RA area because it has not established self-reproducing populations and its distribution is currently narrowing across the country. The results of this study indicate that application of AS-ISK allows the assessment of potentially invasive non-native species and provides a framework of action for the development of management guidelines for non-native species and the conservation of native species (cf. ecological traits such as species competition, habitat preference, food resources, and reproduction). As a case study for the Geum River watershed in South Korea, it is recommended that additional screening studies should be carried out for the non-native species in the four major rivers of South Korea.

본 연구는 선행된 연구자료의 어류군집을 이용하여 강릉남대천 내 이입종의 현황을 파악하고, 수생태계에 악영향을 미칠 수 있는 잠재적 침습성을 평가하고자 실시하였다. 강릉남대천에 서식하고 있는 국내 타수계 이입종은 12종으로 조사되었으며, 1982년 이후로 지속적으로 증가하는 추세를 나타냈다. 이입종의 FISK 평가 결과 피라미 (Zacco platypus)와 참붕어 (Pseudorasbora parva)가 높은 침습성을 보이는 것으로 분석되었다. FISK 질문의 답변에 대한 신뢰도 값은 평균 3.2 (3.06±0.16~3.42±0.13)로 분석되었으며, 최대 신뢰도 값이 4인 것을 고려할 때, 상대적으로 높은 수준을 나타내었다. 조사지점별 물리적 서식지 평가 (Qualitative Habitat Evaluation Index; QHEI) 결과 평균 146 (88~171)으로 최적의 서식처 환경을 유지하고 있는 것으로 분석되었다. 지점별 하천 인근 토지이용률과 QHEI, 이입종 출현빈도를 구분한 결과 하천의 고도가 낮아질수록 QHEI 값은 감소하는 결과를 나타내었으며, 토지이용 측면에서는 산림지역이 감소하고, 도심지역이 점차 증가하는 경향을 나타내었다. 어류군집, QHEI, 하천 인근 토지이용률, 이입종간의 상관관계 분석을 실시한 결과 하천 상·하류간의 연속성을 나타내는 고도와 지점별 종수 (r= -0.782, p=0.0127), 종수와 산림지역 (r= - 0.737, p=0.0234), QHEI와 도심지역 (r= - 0.292, p=0.446)과는 음의 상관성을 나타내었으며, 타수계 이입종의 경우 도심지역과는 양의 상관성 (r=0.313, p=0.412)을 나타내었으나 통계적으로는 유의하지 않은 것으로 분석되었다.

A poor prognosis of oral squamous cell carcinoma (SCC) is partly due to the invasiveness and metastasis of the tumor. One of key elements in tumor invasion and metastasis in the degradation of extracellular matrix is tissue inhibitors of metalloproteinases (TIMPs). This study was performed to determine the expression of TIMP-1 and TIMP-2 of oral SCCs with regard to the histologic invasiveness and differentiation in 5 normal oral mucosa and 36 oral SCCs. The histologic invasiveness of oral SCCs were classified into 4 grades. The differentiation of oral SCCs was divided into 3 grades. The StreptAvidin-Biotin immunohistochemical process, using TIMP-1 and TIMP-2 monoclonal antibodies, was performed to determine the expression of TIMP-1 and TIMP-2. The expression of TIMP-1 was positive in 5 of 17 oral SCCs with weak invasiveness and was positive in 8 of 19 oral SCCs with strong invasiveness. The TIMP-1 expression did not increase significantly with respect to the invasiveness of oral SCCs (P>0.05). The expression of TIMP-2 was strongly positive in 5 out of 17 SCCs with weak invasiveness and was strongly positive in 15 of 19 SCCs with strong invasiveness. The TIMP-2 expression increased significantly with respect to the invasiveness of oral SCCs; the stronger the expression, the stronger the invasiveness (P<0.05). The expression of TIMP-1 and TIMP-2 did not increase significantly with respect to the histologic differentiation. We concluded that with respect to the invasiveness, the TIMP-2 expression increases significantly in oral SCCs but the TIMP-1 expression does not; and that with respect to the histologic differentiation, their expressions do not increase significantly. These results suggested that TIMP-2 can be used as a tool to evaluate the invasiveness of oral SCCs.

Matrix metalloproLeases(MMPs) a re a family of zinc dependent enzymes with the capacity to degrade extracellular matrix prote ins. MMPs express ion correlates with cancer cell invasiveness and metas taslS The purpose of our sωdy was t。 determine the role 0 1' stroma l fïbrob lasts in ca ncer cell invasi on by examining the expression and activity of MMP-2 and -9 We used a YD- lOB squalllous ca rcinoma cell line that was est a blished in Yonsei Univer s ity ‘ College 0 1' Dentistry. We then appli ed two types of s lrolllal fibroblastsdel‘ ived from normal gingival tissue and cancer supporting ti ss ue Morphologic examination of fïbroblas ls was carried out by rnicroscopy and doubling time was measured by MTI assay . YD-lOB cells were cultured by lh ree-d imensional culture using collagen gel with two types of flbroblasts To examine the stromal - mesenchyma l inleraclion. we used a direct co-cul tu re system between YD-IOB cells and fibroblasts. Gelatin zymography was performed to exa llline MMP-2 a ncl 9 activit ies. We found that cancer-derived fibroblasts di splay stel late-shaped cells wi th many cyLopl asmic processes. whereas normal gingi val fibroblasts were spindle shaped. The c1oubling time of bOLh lïbroblasLs was not statistically different. Three-dimensional co-culture 0 1' ca ncer cells with ca n cer- c1erived fïbroblasts induced the formation 0 1' multi - Iayered atypical cells, as compared to culturing with normal gin gival f lbrobl asts Both three-c1 imens ional culture ti ss ues inclucecl the invasive gro￦th of cancer cells into the dermal eq uival enLs . Gelatin zymography s howecl that gelatinolytic activity of MMP-2 was activaterl in both co-culture models. However , MMP-9 ac li vity was not a lterecl in YD-lOB carcinoma cells In conclusion. enhanced MMP-2 activity was inc1 uced by boLh cance r- c1eri vecl a ncl norlllal gingival fibroblasts. suggesting that the potential to invacle by stromal fibroblasts was noL l imilecl to ca ncer- c1 eri ved lïbroblasts