#244 ‒ The history of the cell, cell therapy, gene therapy, and more | Siddhartha Mukherjee

Feb 27, 2023 Episode Page ↗
Overview

This episode features Dr. Siddhartha Mukherjee, an oncologist and Pulitzer Prize-winning author, discussing his book "The Song of the Cell." He covers the evolution of cells, cell and gene therapies like CRISPR, ethical dilemmas in gene editing, and personal insights into his writing process and mental health.

At a Glance
10 Insights
1h 40m Duration
18 Topics
9 Concepts

Deep Dive Analysis

Where The Song of the Cell Fits in Sid Mukherjee's Work

The Discovery of the Cell and Germ Theory's Impact on Medicine

The Evolutionary Drive for Multicellular Life

Ratcliffe's Yeast Experiment on Multicellular Evolution

Four Types of Cell Therapies

The Jesse Gelsinger Gene Therapy Tragedy and Its Aftermath

CAR T-cell Therapy for Cancer Treatment

Cost Reduction in CAR T-cell Therapy

Gene Therapy Approaches for Sickle Cell Anemia

The CRISPR Gene Editing Revolution

Ethical Questions Around Human Germline Gene Editing: The Case of JK

The Complexity of Genetics in Mental Illness

Two Types of Problems in Science: Eye in the Sandstorm vs. Sand in the Eye

Understanding Neural Networks and Synaptic Communication

The Importance of Learning by Doing in Science and Medicine

Sid Mukherjee's Unique Writing Process

Falls as a Liability of Multicellular Existence and Organ Failure

Sid Mukherjee's Decision to Open Up About Depression

Gene as a Score

The human genome, or any genome, is likened to a lifeless score of music, a chemical code (DNA). It requires a 'musician' to bring it to life, which is the cell.

Cell as a Musician

The cell is the entity that brings the lifeless genetic code (the gene) to life. Without the cell, the encoded information would be useless, much like a musical score without a musician to play it.

Disease vs. Desire

This is a critical distinction in gene editing ethics. 'Disease' is fundamentally linked to human suffering, while 'desire' refers to the aspiration to ameliorate suffering even when no suffering is present, or to enhance traits.

Shove Genes

These are powerful genes that strongly push an individual in one direction for a trait or condition, such as the single gene mutation in Marfan syndrome causing extreme height. They are relatively rare.

Nudge Genes

These genes contribute incrementally to a trait or condition, moving an individual 'little by little' towards a phenotype. Most mental illnesses are thought to be consequences of hundreds of these small genetic nudges rather than a single shove gene.

Eye in the Sandstorm Problem

A type of scientific problem where existing information or theories no longer fit observations, requiring a completely new paradigm or fundamental shift in thinking, similar to the transition from Newtonian to quantum physics.

Sand in the Eye Problem

A different type of scientific problem where almost everything fits within a theory, except for one specific fact. This indicates the theory is nearly correct but has an important missing piece, like the discovery of synapses in neuronal transmission.

Synapse

The space between neurons where an electrical signal is converted into a chemical signal, and then back into an electrical signal. This conversion allows for the 'weighting' or modulation of signals, enabling complex learning networks and functions like consciousness.

Body as a Citizenship

This metaphor describes the human body as a complex network where different organs and cell types depend on each other to function. The failure of one part, like a broken bone, can cascade through the system, leading to overall collapse and organ failure.

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How does Siddhartha Mukherjee's book 'The Song of the Cell' fit into his prior work?

It is part of a 'Life Series' trilogy/quartet. It follows 'The Gene' (the smallest unit of information) and precedes 'The Emperor of All Maladies' (the dysfunctional aberrant cell), explaining how the cell brings the gene to life.

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What was the evolutionary drive for multicellular life?

Multicellularity evolved independently multiple times, likely driven by advantages in predation (being bigger, having specialized defenses, mobility) and better access to food and resources, despite single-celled organisms being extraordinarily successful.

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What are the four types of cell therapies?

The four types are: 1) using a drug to change cell behavior (e.g., antibiotics), 2) transferring unmodified cells (e.g., blood transfusion), 3) using cells to synthesize substances (e.g., insulin, antibodies), and 4) genetically modifying cells for therapeutic reasons (e.g., CAR T-cells).

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What happened in the Jesse Gelsinger gene therapy trial?

Jesse Gelsinger, a teenager with a mild genetic liver enzyme defect, died from a severe, hyperactive immune response to the adenovirus vector used to deliver the corrected gene, leading to a decade-long freeze in gene therapy research.

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How does CRISPR gene editing differ from earlier gene therapy methods?

Earlier methods involved inserting a new, foreign page (gene) into the genome, which could be recognized as foreign and inserted in unintended places. CRISPR allows for extraordinarily precise changes to a single word (gene) within the existing genetic 'library', either deleting or changing it, leaving the rest intact.

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What ethical concerns arose from the first human gene-edited babies (Lulu and Nana)?

A Chinese scientist, JK, used gene editing to make embryos HIV-resistant, despite the children having zero risk of HIV infection via IVF. This was deemed unethical because it crossed the line from treating disease (suffering) to fulfilling a 'desire' (scientific aspiration) without medical necessity.

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Why is it difficult to use gene editing for mental health conditions like autism or schizophrenia?

Most mental illnesses are not caused by single 'shove genes' with high penetrance, but rather by 'nudge genes' – hundreds of small genetic variations that cumulatively increase risk. Current gene editing technology is limited to one or a few genes, making it impractical for such complex polygenic conditions.

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Why does the nervous system convert electrical signals to chemical signals and back?

This conversion at synapses allows for modulation and 'weighting' of signals. Instead of a simple 'on/off' electrical impulse, the chemical signal can be adjusted in strength, enabling complex learning networks, discrimination, and the nuanced 'music of the brain'.

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What is the value of 'learning by doing' in science and medicine?

Textbook knowledge provides foundations but doesn't teach how to troubleshoot failures, select patients for clinical trials, manage complications, or address unexpected issues like contamination. This practical, experiential learning is crucial for translating science into human medicine.

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Why did Sid Mukherjee choose to write about his personal struggle with depression?

He made a conscious choice to challenge the stigma and 'victimhood' associated with mental disorders. He aims to frame depression as an 'organic disorder' involving dysfunctional mood-regulating neurons, akin to type 1 diabetes being a pancreatic cell dysfunction, thereby normalizing it as a physiological problem.

1. Practice Rigorous Hand Hygiene

Insist on rigorous handwashing, especially in medical settings, to prevent the transfer of “material substance” (germs) that cause infection and dramatically reduce mortality rates, as demonstrated by Semmelweis’s historical discovery.

2. Prioritize Patient Self-Diagnosis

When diagnosing a patient, always ask them, “What do you think the problem is?” because patients often provide crucial insights into their condition that doctors frequently overlook, aiding in more accurate diagnoses.

3. Embrace Experiential Learning

Recognize that practical skills in medicine and science, such as troubleshooting failures and managing complex projects, cannot be learned from textbooks alone. Actively engage in “learning by doing, learning by being, learning by experiencing” and seek guidance from peers who have practical experience.

4. View Mental Illness Organically

Challenge the notion of “special victimhood” associated with mental disorders by understanding the brain as a cellular cluster with physiology, similar to other organs like the pancreas or heart. This perspective helps remove blame and opens avenues for treating dysfunction in mood-regulating circuits.

5. Ethically Weigh Disease vs. Desire

When considering interventions like gene editing, differentiate between addressing “disease” (fundamentally linked to suffering) and fulfilling “desire” (ameliorating suffering where none exists). Prioritize interventions that alleviate actual suffering over those driven purely by scientific aspiration or enhancement.

6. Adopt a Holistic Writing Process

Use writing as a method for thinking and understanding, drawing from diverse sources like history, mythology, philosophy, and personal experiences. Combine memoir, journalistic, and travel writing to create a comprehensive and personal narrative that invites readers into your perspective.

7. Deepen Health Knowledge via Membership

To take your knowledge of health and wellness to the next level, consider joining a membership program that offers more in-depth, exclusive content, as suggested by the podcast host.

8. Read Mukherjee’s Science Books

For a profound understanding of life, cells, and medicine, read Siddhartha Mukherjee’s books, particularly “The Song of the Cell,” which offers a captivating journey through the history and future of cellular biology.

9. Strategic Reading of Science Trilogy

When reading Siddhartha Mukherjee’s “Life Series” (The Gene, The Song of the Cell, The Emperor of All Maladies), consider reading them chronologically as they appeared for a story that progressively delves deeper into medical mysteries, or start with “The Gene,” then “The Cell,” and finally “The Emperor of All Maladies” to understand the progression from information to life to dysfunction.

10. Understand Biophysical Size Limits

To understand the natural biophysical limitations on creature size, seek out Stephen Gould’s essay that discusses the volume-to-surface area ratio and its impact on an organism’s ability to sustain aerobic living.

Every function that we carry out, regardless of its origin or regardless of what that function is, is a consequence of cellular physiology. We ourselves and everything that we do is cellular, is a consequence of something happening in some cell.

Siddhartha Mukherjee (quoting Rudolf Virchow)

Every illness is the consequence of some cell behaving incorrectly.

Siddhartha Mukherjee (quoting Rudolf Virchow)

The most important question that you ever ask in medicine, when you're trying to diagnose a patient is to ask the patient, what do you think the problem is?

Siddhartha Mukherjee

Gene therapy is really cell therapy. If you put the gene in the wrong cell in the wrong place at the wrong time, you get nothing. You get the disaster.

Siddhartha Mukherjee

The human genome is a library. Imagine the human genome as a massive library. If it was printed in normal text, it would contain 80,000 books, a massive encyclopedia, stretching across a massive library.

Siddhartha Mukherjee

Disease is fundamentally linked to suffering. When we talk about disease, we talk about human suffering. When we talk about desire, we talk about the idea or aspiration to ameliorate suffering, even where there's no suffering involved, as far as we can tell.

Siddhartha Mukherjee

Troubleshooting your way out of failure is the most standard way that we think about medicine and biology.

Siddhartha Mukherjee

Ratcliffe's Yeast Multicellularity Experiment

Siddhartha Mukherjee (describing William Ratcliffe's work)
  1. Take single-celled yeast and culture them.
  2. Allow the yeast to grow.
  3. Collect the sediment, as anything multicellular will sink to the bottom of the flask.
  4. Allow the collected sediment to grow again in another cycle of evolution.
  5. Repeat this process for about 30 to 40 cycles.
40 years
Period of silence in genetics after Mendel's work A period where basically nothing relevant happened after Gregor Mendel's pioneering work.
20% to 30%
Maternal mortality rate from childbirth in Ward 1 (run by doctors) in Semmelweis's time One out of five to one out of three women died in this ward.
500
Number of single-lens microscopes made by Antonie van Leeuwenhoek These were tiny, difficult-to-make instruments.
30 to 40 cycles
Cycles for yeast to evolve multicellular forms in Ratcliffe's experiment This took approximately 60-90 days.
$500,000 to $1,000,000
Cost of CAR T-cell therapy per person in the United States This is an astronomical cost.
10-fold to 20-fold
Reduction in CAR T-cell therapy cost achieved in India Achieved through cheaper virus production, reduced patent burden, changed machinery, and lower hospital costs.
80,000 books
Number of books in the human genome (analogy) If the human genome were printed in normal text, it would fill a massive library.
10% to 30%
12-month mortality rate for people over 65 who fall and break their femur Depending on the study, this is a significant mortality rate following such an injury.