• Animal cells and systems
• /
• 제5권3호
• /
• pp.243-246
• /
• 2001

Human endoqenous retroviral long terminal repeats (LTRs) have been found to be coexpressed with sequences of genes closely located nearby. It has been suggested that the LTR elements have contributed to structural changes or genetic variations of human genome connected to various diseases and evolution. Using cDNA library derived from placenta tissue, we performed PCR amplification and identified five new HERV-W LTR elements. Those LTR elements showed a high degree of sequence similarity (98-99%) with HERV-W LTR (AF072500). A phylogenetic tree obtained by the neighbor-joining method revealed that HERV-W LTR elements could be mainly divided into two groups through evolutionary divergence. Five new HERV-W LTR elements (pla-1, 4, 5, 6, 7) belonged to the group I with AX000960, AF072504, and AF072506 from GenBank database. The data suggest that several copy numbers of the HERV-W LTR elements are transcribed in placenta and may contribute to the understanding of biological function such as human placental morphogenesis.

• BMB Reports
• /
• 제54권7호
• /
• pp.368-373
• /
• 2021

The vertebrate genome contains an endogenous retrovirus that has been inherited from the past millions of years. Although approximately 8% of human chromosomal DNA consists of sequences derived from human endogenous retrovirus (HERV) fragments, most of the HERVs are currently inactive and noninfectious due to recombination, deletions, and mutations after insertion into the host genome. Several studies suggested that Human endogenous retroviruses (HERVs) factors are significantly related to certain cancers. However, only limited studies have been conducted to analyze the expression of HERV derived elements at protein levels in certain cancers. Herein, we analyzed the expression profiles of HERV-K envelope (Env) and HERV-R Env proteins in eleven different kinds of cancer tissues. Furthermore, the expression patterns of both protein and correlation with various clinical data in each tissue were analyzed. The expressions of both HERV-K Env and HERV-R Env protein were identified to be significantly high in most of the tumors compared with normal surrounding tissues. Correlations between HERV Env expressions and clinical investigations varied depending on the HERV types and cancers. Overall expression patterns of HERV-K Env and HERV-R Env proteins were different in every individual but a similar pattern of expressions was observed in the same individual. These results demonstrate the expression profiles of HERV-K and HERV-R Env proteins in various cancer tissues and provide a good reference for the association of endogenous retroviral Env proteins in the progression of various cancers. Furthermore, the results elucidate the relationship between HERV-Env expression and the clinical significance of certain cancers.

• 생명과학회지
• /
• 제25권4호
• /
• pp.481-485
• /
• 2015

수백만 년 전부터 인간의 유전체에는 retrovirus의 유전자들이 삽입되기 시작하였다. 이러한 retrovirus의 유전자들은 결실 혹은 nonsense mutation등 여러 영향으로 지금은 더 이상 활동성 있는 바이러스로서의 역할을 못하는 흔적으로만 남아 있는 형태로 존재하며 이러한 내생(endogenous) retrovirus를 human endogenous retrovirus (HERV)라 부른다. HERV의 각 유전자들은 완성된 활동성을 지닌 바이러스를 만들어 내지는 못하지만 여전히 부분적으로 발현이 가능하고 심지어는 바이러스 particle 까지 만들어지는 것이 관찰되었다. 이러한 내성 retrovirus 에 반해 실질적으로 감염되고 활동하여 질병을 야기하는 외인성(exogenous) retrovirus들이 있는데 이 중 human immunodeficiency virus (HIV)는 인간의 생명을 위협하는 대표적 바이러스로 가장 많이 연구되고 있는 바이러스중의 하나이다. 최근 흔적으로만 존재하는 것으로 보고된 HERV가 실질적으로 활성화된 바이러스인 HIV의 감염에 의해 활성화되고 발현이 증가할 뿐 아니라 HIV 감염의 여러 과정에 관여하고 있다는 연구 결과가 보고되고 있다. 또한 이러한 현상을 이용하여 HIV의 백신 및 치료 방법으로 HERV를 이용하고자 하는 시도가 활발히 이루어지고 있다. 이 리뷰에서는 HIV 감염에 의한 HERV의 활성화 및 관련 상호 기작에 관한 연구를 소개하고 HERV를 이용한 HIV의 백신 및 치료제 개발을 위한 시도들을 함께 소개하고자 한다.

• Reproductive and Developmental Biology
• /
• 제32권2호
• /
• pp.105-110
• /
• 2008

The endogenous retrovirus-like elements (HERVs) found on several human chromosomes are somehow involved in gene regulation, especially during the transcription level. HERV-H, located on chromosome Xp22, may regulate gastrin-releasing peptide receptor (GRPR) in connection with diverse diseases. By suppression subtractive hybridization screen on SV40-immortalized lung fibroblast (WI-38 VA-13), we discovered that expression of HERV-HX2, a clustered HERV-H sequence on chromosome X, was upregulated in immortalized lung cells, compared to that of normal cells. Expression of HERV-HX2 was then analyzed in various cell lines, including normal somatic cells, cancer cells, SV40-immortalized cells, and undifferentiated and differentiated human embryonic stem cells. Expression of HERV-HX2 was specifically upregulated in continuously-dividing cells, such as cancer cells and SV40-immortalized cells. Especially, HERV-HX2 in HeLa cells was highly upregulated during the S phase of the cell cycle. Similar results were obtained in hES cells, in which undifferentiated cells expressed more HERV-HX2 mRNA than differentiated hES cells, including neural precursor and endothelial progenitor cells. Taken together, our results suggest that HERV-HX2 is upregulated in cancer cells and undifferentiated hES cells, whereas downregulated as differentiation progress. Therefore, we assume that HERV-HX2 may playa role on proliferation of cancer cells as well as differentiation of hES cells in the transcriptional level.

• 한국생명과학회:학술대회논문집
• /
• 한국생명과학회 2003년도 제39회 학술심포지움
• /
• pp.105-105
• /
• 2003

• 한국동물학회:학술대회논문집
• /
• 한국동물학회 2003년도 한국생물과학협회 학술발표대회
• /
• pp.198.4-198
• /
• 2003

No Abstract, See Full Text

• Molecules and Cells
• /
• 제26권1호
• /
• pp.53-60
• /
• 2008

We characterized the human endogenous retrovirus (HERV-W) family in humans and primates. In silico expression data indicated that 22 complete HERV-W families from human chromosomes 1-3, 5-8, 10-12, 15, 19, and X are randomly expressed in various tissues. Quantitative real-time RT-PCR analysis of the HERV-W env gene derived from human chromosome 7q21.2 indicated predominant expression in the human placenta. Several copies of repeat sequences (SINE, LINE, LTR, simple repeat) were detected within the complete or processed pseudo HERV-W of the human, chimpanzee, and rhesus monkey. Compared to other regions (5'LTR, Gag, Gag-Pol, Env, 3'LTR), the repeat family has been mainly integrated into the region spanning the 5'LTRs of Gag (1398 bp) and Pol (3242 bp). FISH detected the HERV-W probe (fosWE1) derived from a gorilla fosmid library in the metaphase chromosomes of all primates (five hominoids, three Old World monkeys, two New World monkeys, and one prosimian), but not in Tupaia. This finding was supported by molecular clock and phylogeny data using the divergence values of the complete HERV-W LTR elements. The data suggested that the HERV-W family was integrated into the primate genome approximately 63 million years (Myr) ago, and evolved independently during the course of primate radiation.

• 생명과학회지
• /
• 제13권2호
• /
• pp.236-240
• /
• 2003

인간의 면역계는 외부의 병원균 등의 침입에 대하여 매우 강력한 방어작용을 수행하고 있다. 하지만, 때로 면역계의 손상으로 인해 비정상적인 면역작용이 유발됨으로써 면역성 질환이 야기되기도 한다. 특히, 자가면역 질환은 그 종류가 매우 다양하며 심각한 위험을 초래하기도 한다 이들 질환에 대한 활발한 병인학적 연구가 진행되고 있으나, 아직 정확한 메커니즘을 밝히지는 못하고 있다. 자가면역성 당뇨병의 원인 유전자로 인간의 게놈에 내생하고 있는 HERV가 거론된 후, 사이토카인의 변화나 외생 레트로바기러스의 감염에 의해 HERV의 발현이 활성화되어 superantigen으로 작용함으로써 비정상적인 면역반응이 유도된다는 새로운 사실이 밝혀져 많은 주목을 끌고 있다. 이는 내생 레트로바이러스 유래의 superantigen과 인간의 질병과의 관련성을 비교적명확하게 제시함으로써, 자가면역 질환의 극복을 위한 향후 연구에 주요한 실마리를 제공하고 있다.

• Animal cells and systems
• /
• 제8권Supplyment
• /
• pp.53-53
• /
• 2004

• 한국유전체학회:학술대회논문집
• /
• 한국유전체학회 2005년도 The 14th Korea Genome Conference
• /
• pp.75-75
• /
• 2005