Curan por primera vez un cáncer aprovechando células clonadas del propio paciente

Europa Press - jueves, 19 de junio, 19.15

LONDRES/SEATTLE, 19 (OTR/PRESS) - Por primera vez, un equipo de médicos norteamericanos han curado un cáncer de piel en estado avanzado gracias a una nueva técnica que consiste en clonar las células del sistema inmunitario del propio paciente para multiplicarlas 'in vitro' y volverlas a implantar en el paciente. De esta forma, se ayuda al sistema inmunitario a luchar contra esta enfermedad y abre la puerta a una posible cura de otros muchos tumores contra los que las defensas del paciente no pueden luchar por sí solas.
(Publicidad)

Reforzar el sistema inmunitario para que las propias células del cuerpo luchen contra el cáncer. Esta es la base de una nueva forma de tratar el melanoma a la que ha llegado un equipo de investigadores norteamericanos y que han plasmado en un artículo de la England Journal of Medicine. La nueva técnica consiste en extraer al paciente una muestra de células sanas del sistema inmunitario para, ya en el laboratorio, multiplicarlas por unos cinco mil millones e insertarlas después en el paciente.

Gracias a esta clonación se ha conseguido por primera vez curar a un hombre de 52 años que padecía un melanoma en estado avanzado, que ya había afectado a los pulmones y a los nódulos linfáticos. Apenas dos meses después de que los médicos del Fred Hutchinson Cancer Research Center, en Seattle (Estados Unidos), inyectaran las células clonadas en el paciente, observaron que los tumores habían desaparecido y, dos años después, el hombre se encuentra en perfecto estado y totalmente curado del cáncer.

La célula responsable de este gran avance en la lucha contra una enfermedad que cada año se cobra miles de vidas es la CD4 o T4, un tipo de glóbulo blanco que se dedica a luchar contra las infecciones. Por ello, es la que utilizan los científicos para clonarla e insertarla en el paciente para que su sistema inmunitario sea más fuerte que el propio cáncer, según una información de la BBC recogida por otr/press.

APLICACIÓN EN OTROS PACIENTES

El sistema inmunitario juega un papel crucial para cualquier enfermedad, especialmente cuando esta es tan dura como el cáncer. Por ello, durante años los médicos han tratado de encontrar una técnica que les permita reforzar las defensas del paciente como mejor estrategia para vencer al cáncer.

De esta forma, se abre la puerta a la esperanza para otros tipos de cáncer, aunque los responsables del desarrollo de esta técnica prefieren mantener la prudencia y destacar que tan sólo la han utilizado en un paciente con un tipo concreto de cáncer. Así, el doctor Cassian Yee, líder del proyecto, señaló que "para este paciente ha sido un éxito, pero necesitaríamos confirmar la efectividad de la terapia en un estudio más amplio".

Por su parte, el catedrático Karol Sikora, experto en oncología del Imperial College de Londres, se mostró más optimista con respecto a la aplicación de esta técnica e insistió en que tendrá una aplicación potencial. "Seremos capaces de aprovechar el poder del sistema inmunológico. Aprenderemos cómo controlar el cáncer", aseguró.

EXTRAIDO: http://es.noticias.yahoo.com/ep/20080619/tes-curan-por-primera-vez-un-cncer-aprov-c5455be.html

Nanotechnology, Biomolecules And Light Unite To 'Cook' Cancer Cells

ScienceDaily (Jun. 17, 2008) — Researchers are testing a new way to kill cancer cells selectively by attaching cancer-seeking antibodies to tiny carbon tubes that heat up when exposed to near-infrared light.


Researchers used monoclonal antibodies that targeted specific sites on lymphoma cells to coat tiny structures called carbon nanotubes. Carbon nanotubes are very small cylinders of graphite carbon that heat up when exposed to near-infrared light. (Credit: Image courtesy of Wikimedia Commons)





Biomedical scientists at UT Southwestern Medical Center and nanotechnology experts from UT Dallas describe their experiments in a study available online and in an upcoming print issue of Proceedings of the National Academy of Sciences.

Scientists are able to use biological molecules called monoclonal antibodies that bind to cancer cells. Monoclonal antibodies can work alone or can be attached to powerful anti-cancer drugs, radionuclides or toxins to deliver a deadly payload to cancer cells.

In this study, the researchers used monoclonal antibodies that targeted specific sites on lymphoma cells to coat tiny structures called carbon nanotubes. Carbon nanotubes are very small cylinders of graphite carbon that heat up when exposed to near-infrared light. This type of light, invisible to the human eye, is used in TV remote controls to switch channels and is detected by night-vision goggles. Near-infrared light can penetrate human tissue up to about 1½ inches.

In cultures of cancerous lymphoma cells, the antibody-coated nanotubes attached to the cells' surfaces. When the targeted cells were then exposed to near-infrared light, the nanotubes heated up, generating enough heat to essentially "cook" the cells and kill them. Nanotubes coated with an unrelated antibody neither bound to nor killed the tumor cells.

"Using near-infrared light for the induction of hyperthermia is particularly attractive because living tissues do not strongly absorb radiation in this range," said Dr. Ellen Vitetta, director of the Cancer Immunobiology Center at UT Southwestern and senior author of the study. "Once the carbon nanotubes have bound to the tumor cells, an external source of near-infrared light can be used to safely penetrate normal tissues and kill the tumor cells.

"Demonstrating this specific killing was the objective of this study. We have worked with targeted therapies for many years, and even when this degree of specificity can be demonstrated in a laboratory dish, there are many hurdles to translating these new therapies into clinical studies. We're just beginning to test this in mice, and although there is no guarantee it will work, we are optimistic."

The use of carbon nanotubes to destroy cancer cells with heat is being explored by several research groups, but the new study is the first to show that both the antibody and the carbon nanotubes retained their physical properties and their functional abilities -- binding to and killing only the targeted cells. This was true even when the antibody-nanotube complex was placed in a setting designed to mimic conditions inside the human body.

Biomedical applications of nanoparticles are increasingly attracting the attention of basic and clinical scientists. There are, however, challenges to successfully developing nanomedical reagents. One is the potential that a new nanomaterial may damage healthy cells and organisms. This requires that the effects of nanomedical reagents on cells and organisms be thoroughly studied to determine whether the reagents are inherently toxic.

"There are rational approaches to detecting and minimizing the potential for nonspecific toxicity of the nanoparticles developed in our studies," said Dr. Rockford Draper, leader of the team from UT Dallas and a professor of molecular and cell biology.

Other researchers from UT Southwestern involved in the research were lead authors Pavitra Chakravarty, a graduate student in biomedical engineering, and Dr. Radu Marches, assistant professor in the Cancer Immunobiology Center. Authors from UT Dallas' Alan G. MacDiarmid NanoTech Institute were Dr. Inga Musselman, Dr. Paul Pantano and graduate student Pooja Bajaj. Two undergraduate students in UT Southwestern's Summer Undergraduate Research Fellowship program -- Austin Swafford from UT Dallas and Neil Zimmerman from the Massachusetts Institute of Technology -- also participated.

The research was supported by the Cancer Immunobiology Center at UT Southwestern, the Robert A. Welch Foundation, the Department of Defense and the Center for Applied Biology at UT Dallas.

Dr. Vitetta is a co-inventor on a patent describing the techniques outlined in the study.

ournal reference:

1. Chakravarty et al. Thermal ablation of tumor cells with antibody-functionalized single-walled carbon nanotubes. Proceedings of the National Academy of Sciences, Published online on June 16, 2008 DOI: 10.1073/pnas.0803557105


Extraido de :http://www.sciencedaily.com/releases/2008/06/080616170807.htm