Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings PowerPoint® Lectures Lectures by April Lynch Tumor-Busting Viruses Current Issues in Biology, Volume 2 Scientific American

Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Tumor-Busting Viruses How can doctors kill cancer cells without harming healthy ones? Such targeted treatment is one of the biggest challenges in cancer care. This image shows how cancerous cells intermingle with healthy ones. Melanoma, or skin cancer cells, are shown in green amid healthy cells, shown in red.

Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Tumor-Busting Viruses A new answer may lie in virotherapy. This type of treatment uses scientifically-engineered viruses to target cancer cells.

Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Tumor-Busting Viruses Some viruses, such as engineered adenoviruses, show promise at selecting and destroying cancer cells. They kill tumor cells by invading through unique receptors on the surface of cancer cells, and then burst the cells open or make them more vulnerable to traditional chemotherapy.

Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Tumor-Busting Viruses Here are examples of cancer experiments involving virotherapy.

Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Concept Review Tumor-Busting Viruses But more research is needed to prevent engineered adenovirus therapies from having dangerous side effects. Normal adenoviruses are common, causing illnesses such as colds. Many people could have immune systems already primed to fight adenoviruses, and suffer severe immune reactions from engineered ones. In 1999, an 18-year-old patient died after suffering a severe immune reaction in an adenovirus experiment.

Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Testing Your Comprehension Tumor-Busting Viruses What is virotherapy? a) stimulating cancer tissue with sonic pulses b) exposing patients to cold viruses to boost their immunity c) applying engineered viruses to infect and kill cancer cells d) putting patients in a pressure chamber during treatment

Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Testing Your Comprehension Tumor-Busting Viruses What is virotherapy? c) applying engineered viruses to infect and kill cancer cells

Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Testing Your Comprehension Tumor-Busting Viruses Which of these structures would you not find in a virus? a) mitochondrion b) ribosome c) nucleus d) all of the above

Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Testing Your Comprehension Tumor-Busting Viruses Which of these structures would you not find in a virus? d) all of the above

Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Testing Your Comprehension Tumor-Busting Viruses How do viruses selectively attach to target cells? a) target cells display unique cell-surface receptors b) target cells secrete unique identification proteins c) viruses attach to specific materials engulfed by cells d) viruses are not selective about target cells

Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Testing Your Comprehension Tumor-Busting Viruses How do viruses selectively attach to target cells? a) target cells display unique cell-surface receptors

Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Testing Your Comprehension Tumor-Busting Viruses What would be the purpose of giving patients immuno- suppressive drugs during virotherapy with adenoviruses? a) adenovirus can damage a normal immune system b) to hold the immune system in reserve after therapy c) to minimize side effects caused by immune response d) none of the above is correct

Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Testing Your Comprehension Tumor-Busting Viruses What would be the purpose of giving patients immuno- suppressive drugs during virotherapy with adenoviruses? c) to minimize side effects caused by immune response

Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Biology and Society Tumor-Busting Viruses If I were diagnosed with a deadly form of cancer, and were offered the chance to join a virotherapy research trial, I’d be willing to try this experimental therapy. Strongly Agree Strongly Disagree A. E. C. B. D.

Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Thinking about Science Tumor-Busting Viruses What would be important medical safety steps to include in a research trial studying whether a certain brain cancer could be fought with engineered adenovirus?

Copyright © 2006 Pearson Education, Inc. publishing as Benjamin Cummings Interpreting Data and Graphs Tumor-Busting Viruses Using this illustration as a guide, describe how an engineered virus can infect and kill a cancer cell, while leaving a healthy cell alone.