2009년 11월 13일 금요일
유방암 치료의 새 희망! 암 줄기세포를 찾아내자.
전신의 혈액을 타고 암세포가 돌아다니지요.
이 암세포중에 특히 암 줄기세포가 많이 있다면?
암 줄기세포로 실험을 한 결과, 기존의 항암제, 호르몬요법, 항체요법에 모두
반응을 하지 않았다는 연구결과도 있습니다.
유방암 뿐 아니라, 암의 사망률이 높은 것은, 이렇게 약제에 반응을 하지 않는
암들이 많기 때문입니다.
약들이 반응을 안하는 중요한 이유중 하나가 암도 암줄기세포라는 것을 가지고 있으며
이 암줄기세포가 항암제에 듣지 않기 때문이라는 것은,
앞으로 약제 개발의 방향을 제시해 줍니다.
이 암줄기세포를 죽이지 않으면 암치료가 성공하지 못한다는 것이지요.
이 암줄기세포를 죽이는 것은 NKcell일 수도 있고,
아직 알지 못하는, 그 어떤 인자에 의해 암줄기세포가 빠르게 분화하고
노화하여 apoptosis를 일으켜 버리는 방법도 있을 것 같습니다.
이렇게 암줄기세포를 분화시키는 약을 개발할 수 있다면, 대박나겠네요.
부작용으로, 정상세포들까지 분화해 버리면? 노화가 진행이 되겠지요 .
다음 연구 결과를 보세요.
The researchers were testing the theory that cancer cells circulating in the bloodstream may be linked with the stem cell like tumor cells that are thought to be the active source of metastatic spread from primary tumors. They were also testing the theory that these cells may undergo physical or biochemical changes which allow these cells to travel and metastize without getting affected by conventional cancer therapies.
The researchers tested blood samples from patients with metastatic breast cancer who were receiving palliative chemotherapy, antibody or hormonal therapy. Using the Company's AdnaTest™ EMT1/StemCell product, they looked for the presence of four different EMT and stem cell biomarkers and compared these findings with the presence of circulating tumor cells and the response to therapy. The results showed that a major proportion of the circulating cancerous tumor cells in these patients had the expected biomarkers and tumor stem cell characteristics.
Based upon these results, the researchers concluded that the detection of these biomarkers in circulating tumor cells could be used to better diagnose patients, and evaluate the effectiveness or the potential risk of resistance to prescribed treatments sooner.
출처: medicalnewstoday
2009년 11월 12일 목요일
폐조직도 만들어 냅니다. 배아줄기세포로!
다른 모든 장기도 그렇지만, 폐도 손상되면 회복이 잘 안됩니다.
특히, 만성적으로 염증이 있는 환자는 폐이식 이외에는 답이 없었습니다.
그런데,
배아줄기세포로 폐조직을 성공적으로 만들어 내었다고 합니다.
이는 아마도 성체줄기세포로는 한계가 있어서 안될것이고 오직 배아줄기세포만 가능할 것 같습니다.
아직은 실험단계이지만, 만성폐쇄성폐질환으로 고생하는 분들에게 희망이 되겠네요.
출처
iPS와 ES는 같은 것이 아닙니다.
엄연히 methylation에서 차이가 난답니다.
오히려, 암세포와 methylation에서 유사한 점이 많다고 합니다.
"The surprise," says Feinberg, "is that there is such a degree of overlap between the differently methylated regions and genes that are involved in turning a fibroblast into a stem cell and turning a normal cell into a cancer cell."
따라서, ipS를 ES처럼 임상에 사용하려면, ES와 유사하게 methylation을 시키는 기술이
개발되어야 할 것입니다.
암세포, 배아줄기세포, IPS... 빠른 속도로 여러번 자기 복제를 한다는 점에서 동일한 놈들이지요.
아니나 다를까. methylation도 비슷하다네요.
이 IPS를 잘 연구하면, 암을 치료하는 또하나의 방법이 나오지 않을까요?
커다란 암덩어리를 분화시켜버리고, 림파액에 전이된 암은 NK cell로 죽이는 치료를 상상해 봅니다.
소스
건망증도 줄기세포로 치료할 수 있을까?
실험은 방사선으로 뇌세포를 파괴시킨 쥐를 대상으로 했답니다.
줄기세포를 이식했더니, 정상수준으로 회복이 되었고 이식안한쥐는
50%수준으로 감소했답니다.
뇌종양이 있어서 뇌에 방사선을 쬐는 사람들의 경우에는 필연적으로,
정상뇌세포도 손상이 되고, 그러면, 기억력, 인지력의 장애가 생깁니다.
이런 환자들에게 , 희망이되겠네요.
종양에게 더 강하게 맘대로 쐬고,
다친 정상세포는 되돌리면 되니까요.
또한, 치매, 건망증환자도 도움이 되지 않을까요?
출처
경추손상으로 사지 완전마비도 되돌리는 배아줄기세포!!!
배아줄기세포치료를 승인했지요.
그런데 이것은 경추를 제외하고 그 아랫부위의 척추가 손상된 사람들에게만 승인된것이었답니다.
이유는, 아직 경추손상에 대한 동물실험이 끝나지 않았었기 때문이지요.
이번에 , 쥐를 상대로 한 동물실험이 성공했다네요.
경추손상으로 100% 마비를 만든 쥐에게 배아줄기세포를 투여했더니,
손상의 97%가 회복이 되었다고 합니다.
오늘도 도로를 달리는 폭주족 오토바이들...
줄기세포 치료제의 발전을 믿고 그러는 걸까요?
source
당뇨합병증(DM foot) 을 줄기세포유도제로 완치??
"It appears that DSC127 directs MSCs to the injury site, mobilizing them to help repair wounded or burned skin, accelerate healing and reduce scar formation," said Edward J. Quilty, Chairman & CEO of Derma Sciences Inc.
이 DSC127이라는 넘을 당뇨로인해 궤양이 생긴 발에 주사를 하면, 그 쪽으로 혈관을 타고 , 혹은 주위 조직에서 ,
MSC들이 유도되어 , 궤양을 치료한다는 생각입니다.
실제로 , 동물실험에서 성공을 했다고 합니다.
지금까지는, 지방에서 MSC를 추출해서 그것을 직접 병변에 주사하는 방법이나 IV하는 방법을 써왔는데요.
그러려면, 일단 어딘가 상처를 내서 지방을 추출해야 하지요.
골수의 경우에도 마찬가지로 상처를 내야 하지요.
배아줄기세포치료는 윤리적, 안전성 문제로 조금 미뤄두고,
IPS도 아직은 실험단계라 미뤄두고,
제대혈 줄기세포는 좋은 대안이지만, 그 공여자 수가 적고, Matching되는 공여자를 만나기도 쉽지 않지요.
따라서, 이렇게 줄기세포 자체가 아닌, 줄기세포를 활성화하고 유도하는 약제들이
앞으로 실제적으로 간편하게 사용되지 않을까요?
응용범위는 낭뇨발부터, 심근경색,당뇨로 혈관이 막혀 다리궤사된 것들, 중풍등등...
혈관질환에서부터 시작하겠군요.
정말 ,MSC를 유도 활성화 한다면, MSC를 쓰는 모든 질환에 응용가능하겠네요
연골이 닳은 OA, 콧대성형, 자가면역질환등등....
알러지비염, 아토피피부염도 연고로 만들면 응용가능 하겠습니다.
DSC127 is an analog of a naturally occuring peptide, Angiotensin, and was developed at the University of Southern California. It has been shown to increase keratinocyte proliferation, increase extracellular matrix production, and increase vascularization. Additionally, histological examination has shown that DSC127 accelerated collagen deposition six-fold. All these help to accelerate dermal tissue repair. The patented amino acid peptide optimizes the wound healing capabilities of Angiotensin while removing all blood pressure effects of the compound.
Extensive pre-clinical studies have demonstrated the efficacy of the compound in accelerating healing and reducing scar formation. Pre-clinical stduies thus far have shown:
Improved in-growth of host tissue into artificial skins
Accelerated healing in full thickness skin excision wounds in rats and diabetic mice
Accelerated healing in partial thickness thermal injuries in guniea pigs
Accelerated healing in a random flap skin model in rats Improved scar reduction in rats
A Phase I safety study in humans was completed in Q4 2007, and patients are currently enrolling into the Phase II efficacy study. This study of 75 patients will look at percentage of diabetic ulcers completely healed over a 12-week period, among other outcomes.
The efficacy of DSC127 and other Angiotensin analogs has been extensively studied, with numerous peer-reviewed articles published. These include:
• Rodgers KE, Roda N, Felix JC, Espinoza T, Maldonado S, diZerega G. Histological evaluation of the effects of angiotensin peptides on wound repair in diabetic mice. Experimental Dermatology 2003;12(6): 784-790.
• Rodgers K, Xiong S, Felix J, Roda N, Espinoza T, Maldonado S, diZerega G. Development of angiotensin (1-7) as an agent to accelerate dermal repair. Wound Repair Regen 2001;9:238-250.
• Rodgers KE, Espinoza T, Felix J, Roda N, Maldonado S, diZerega acceleration of healing, Reduction of fibrotic scar, and normalization of tissue architecture by an angiotensin analogue, norleu3-a(1-7). Plast Reconstr Surg 2003; 111:1195-1206.
• Rodgers, KE, Abiko M, Girgis W, St. Amand KM, Campeau JD, diZerega GS. Acceleration of dermal tissue repair by Angiotensin II. Wound Repair Regen 1997;5:175-183.
• Rodgers, KE, DeCherney AH, St. Amand KM, Dougherty WR, Felix JC,, Girgis W, diZerega GS. Histologic alterations in dermal repair after thermal injury: effects of topical angiotensin II. Burn Care and Rehabilitation 1997;18:381-388.
• Okuyama N, Roda N, Guerrero A, Dougherty W, Nguyen T, diZerega GS, Rodgers KE. Effect of angiotensin II on the viability, vascularity of random flaps in a rat model. Annals Plastic Surgery Res 1999;68:913-918.
• Rodgers KE, Ellefson DD, Espinoza T, Roda N, Maldonado S, diZerega GS. Effect of NorLeu3-A(1-7) on scar formation over time after full thickness incision injury in the rat. Wound Repair Regen 2005;13:309-317.
source: medicalnewtoday , http://www.dermasciences.com/subcategory.php?sid=66&id=1&show=p
2009년 11월 4일 수요일
백혈병에 골수대신 제대혈 줄기세포를 배양하여 이식?
백혈병에 골수이식을 대신해서 더 좋은 결과를 얻을 수 있다고 합니다.
StemEx라는 제대혈 확장기를 개발한 회사도 그 중하나로,
이미 동물실험은 성공했다고 주장합니다.
그런데, 아마도 동물실험은 생생한 제대혈로 했을 것이고,
사람의 경우에는 얼린 것을 쓸 수 밖에 없으니까,
동물실험하고 같은 결과가 나올까요?
한번 얼린 줄기세포를 배양한다는 것이.... 쉽지는 않지요.
또한, HSC를 배양에 성공했다는 거 같은데? 정말일까요?
정말, 동물에서 제대혈의 HSC를 배양하는 데 성공했다면,
사람에서도 희망은 보입니다.
이 회사 주장대로라면, 현재 미국, 유럽에서 3상 임상실험중이랍니다.
아이를 낳는 병원에서 회사로 질소가스로 냉동해서 옮기지 말고,
그 자리에서 바로 충분한 양을 배양해서 , 그 배양한 것을
아주 천천히 얼려서, 세포가 최대한 보존되도록 한다면,
나중에 백혈병에 쓸 수 있을 것으로 보입니다.
관련 기사
관련 회사
관련회사2
관련 논문
725] Nicotinamide Modulates Ex-Vivo Expansion of Cord Blood Derived CD34+ Cells Cultured with Cytokines and Promotes Their Homing and Engraftment in SCID Mice. Session Type: Oral Session, ASH December 12, 2006 Tony Peled, Sophie Adi, Iddo Peleg, Noga G. Rosenheimer, Yaron Daniely, Arnon Nagler, Eitan Fibach, Amnon Peled R&D, Gamida Cell Ltd, Jerusalem, Israel; Hematology, Chaim Sheba Medical Center, Tel Hashomer, Israel; Hematology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel Nicotinamide (NA) is a non-competitive inhibitor of NAD(+)-dependent ADP-ribosyl transferases, of CD38 NADase (a major regulator of cellular NAD levels) and of Sir2 histone-deacetylase. These enzymes are playing a pivotal role in regulation of signal transduction pathways and gene expression. In the present study, we evaluated the effect of NA on the ex-vivo expansion of cord-blood (CB) derived CD34+ cells and their bone-marrow (BM) homing and engraftment potential. Culturing of CD34+ cells for three weeks in the presence of cytokines (SCF, TPO, IL-6, FLT3-ligand) only or cytokines + NA (5mM) resulted in similar expansion of CD34+ cells (40-fold relative to input). However, a remarkable increase in the fraction of CD34+ cells displaying an early progenitor cell phenotype (CD34+Lin-) was observed in the NA-treated cultures as compared with cytokines-only treated cultures (18.6±3% and 0.7±0.06%, n=6, p<0.05, respectively). Tracking the cell-cycle history by PKH2 staining showed fewer division cycles of CD34+ cells cultured with NA. These results may suggest a direct correlation between the rate of proliferation and expansion of CD34+Lin- cells. NA-treated CD34+ cells express similar levels of CXCR4 but display increased migratory activity in response to CXCL12 over CD34+ cells treated with cytokines only (36±19% and 11±4%, n=4, p<0.05, respectively). In order to test their homing potential, similar number of mononuclear cells (MNC), before or following expansion with or without NA, were labeled with CFSE and transplanted into irradiated NOD/SCID mice. Twenty-four hours later the numbers of human cells (CD45+CFSE+) and human progenitor cells (CD34+CFSE+) in the BM were counted. Homing of CD45+CFSE+ cells was comparable in the three groups tested. However, CD34+CFSE+ cells with BM homing potential were 3-fold more numerous in NA-treated cultures relative to cytokines-treated cultures, and 6-fold more than in non-cultured CB cells (n=14, p<0.05). To evaluate engraftment, SCID mice were transplanted with 3x103, 6x103 and 12x103 non-cultured CD34+ cells or their entire progeny
following 3-week expansion with cytokines only or cytokines + NA (n = 63). The frequency of SCID repopulating cells (SRC) was estimated by limiting dilution analysis as 1/ 36,756 (non-cultured), 1/19,982 (cytokines), 1/ 2,620 (NA) (SCID engraftment was considered as ≥0.5% human CD45+ cells). We found that, in correlation with homing, NA-treated cells have a 14- and 7.6-fold more SRC than non-cultured cells or cytokine-treated cells, respectively. The marked increase in SCID engraftment potential following culturing with NA may be attributed to both improved homing of CD34+ cells as well as higher proportion of early progenitor cells within the CD34+ cell compartment. Despite their numerical expansion, progenitor cells generated in cytokine-supplemented cultures have reduced homing and engraftment capacity. Our study demonstrates that NA modulates in-vitro expansion and augments the in-vivo homing and engraftment of CB-derived CD34+ cells cultured with cytokines. Abstract #725 appears in Blood, Volume 108, issue 11, November 16, 2006 Keywords: Engraftment|Ex vivo expansion|Homing
CD34 세포에 cytokine과 동시에 Nicotinamide를 가했더니 cytokine만 준 그룹은 물론, 배양을 안한 그룹보다
생착률과 homing율이 올라갔다고 합니다. 그것도 10배 이상!!!
또한 이렇게 배양을 하니까 early progenitor의 비율도 증가했답니다.
즉, 또리또리한 세포들로만 많이 배양이 되었다는 것입니다.
이 원리를 이용하여 gamida cell에서는 StemEx라는 CD34 세포 배양기기를 만들어 냈답니다.
이것을 이용하여, 제대혈의 HSC를 배양하여, 백혈병에 사용하겠다는 것입니다.
이론적으로는 , 배양 안하는 기존 골수이식보다 생착율이 올라갈 것이고,
면역관용이 더 많으므로, 더 많은 사람들에게 쓰일 수 있을 것입니다.
정확히,
역시 궁금한것은,
냉동했던 제대혈의 HSC도 같은정도로 배양, 생착이 될까요?
면역 관용의 정도는 얼마만큼까지 일까요?
또한, MSC도 이러한 기기로 배양하면 더 생착율을 올릴 수 있지 않을까요?
이 회사가 홈페이지에 공개한 기술입니다.
Gamida Cell employs proprietary technologies to expand populations of functional hematopoietic progenitor cells (HPC). These epigenetic technologies utilize small molecules to modulate differentiation, homing and engrafment abilities of cultured cells. The Phase I/II study of the first developed technology showed preliminarily positive results which prompted a subsequent global, multi-center, pivotal phase III study to further investigate safety and efficacy. www.clinicaltrials.gov
Successful ex vivo expansion of HPC depends on their ability to proliferate while maintaining their basic characteristics. Most protocols for ex vivo expansion utilize various combinations of cytokines that support extensive proliferation of cultured cells. Nonetheless, in vitro proliferation is tightly coupled with commitment and differentiation, thereby lessening the clinical utility of cultured cells. Thus, culture conditions attenuating in vitro differentiation were suggested to support more successful expansion of HPC and to increase their clinical applicability.
Gamida Cell has developed four proprietary technologies for ex vivo expansion of HPC utilizing low molecular weight compounds, which regulate physiological pathways of cell differentiation. Two of the four technologies have been presented in scientific forums. Gamida Cell is applying these expansion technologies to develop a pipeline of products for bone marrow transplantation and tissue regeneration.
Copper Chelator Based Technology
The first technology developed by Gamida Cell is based on the discovery that copper ions modulate self-renewal and differentiation of cultured hematopoietic progenitor cells (HPC). Copper deficiency delays differentiation and prolongs proliferation while increase in cellular copper level, accelerates differentiation and substantially reduce proliferation potential. (Exp Hematol. 2005; 33:1092.). Intriguing, copper deficiency in patients was shown to mimic refractory anemia manifested by excess of immature cells and reduced proportion of differentiated cells in the bone marrow. Oral copper replacement completely normalized the bone marrow findings (Leuk Res. 2008; 32(3):495). Therefore, this mechanism is used to modify the balance between self renewal and differentiation in vitro and in vivo.
The lead molecule of the copper-based technology is the high affinity copper chelator – Tetraethylpentamine (TEPA). TEPA reduces the intracellular copper level, delays differentiation, and enables robust expansion of HPC during the first few weeks in culture. The resulting cell population contains increased proportions and absolute numbers of HPC displaying increased self-renewal potential, and shows high levels of engraftment as well as multi-lineage differentiation potential in pre-clinical in vivo models (Exp Hematol. 2004 Jun;32(6):547-55.)
Most importantly, thepercentage of engrafted human progenitor cells as well as
that of myeloid and lymphoid cells was reproducibly and significantly superior in SCID mice transplanted with TEPA-mediated ex vivo expanded cells than mice transplanted with similar numbers of cells expanded with the cytokine cocktail without TEPA, or with the corresponding cell fraction before expansion.
NAM Based Technology
Ongoing
pre-clinical studies have enabled Gamida Cell to develop an additional
propriety technology based on epigenetic modulation of NAD+ -dependent
ADP ribosyl transferase enzymes. Nicotinamide (NAM), a form of vitamin
B3, shown to be the most potent inhibitor of NAD+ -dependent ADP
ribosyl transferase enzymes, is the lead molecule of this novel
technology. NAM increases the therapeutic potential of stem cells. The
pre-clinical results show the tremendous potential of NAM technology to
improve the homing and rate of engraftment of cord blood derived stem
cells to maximize their full therapeutic potential in bone marrow
transplantation and tissue regeneration. In December 2006, Gamida Cell
addressed the American Society of Hematology in an oral presentation on
the recent results of a pre-clinical study of its NAM technology.
Currently, the company is focused on applying these technologies in
development of new products.
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