David Guy Kirsch is an American oncologist currently the Barbara Levine University Professor at Duke University [1] and an Elected Fellow of the American Association for the Advancement of Science. [2]
He earned his M.D. and Ph.D. at Johns Hopkins University School of Medicine in 2000. [3]
His interests are in studying sarcomagenesis, cancer biology and radiation oncology. [2] His highest cited papers are "Conversion of Bcl-2 to a Bax-like death effector by caspases", [4] at 1332 times, and "Restoration of p53 function leads to tumour regression in vivo", [5] at 1320 times, according to Google Scholar. [6]
Apoptosis is a form of programmed cell death that occurs in multicellular organisms and in some eukaryotic, single-celled microorganisms such as yeast. Biochemical events lead to characteristic cell changes (morphology) and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, DNA fragmentation, and mRNA decay. The average adult human loses between 50 and 70 billion cells each day due to apoptosis. For an average human child between eight and fourteen years old, each day the approximate loss is 20 to 30 billion cells.
Experimental cancer treatments are mainstream medical therapies intended to treat cancer by improving on, supplementing or replacing conventional methods. However, researchers are still trying to determine whether these treatments are safe and effective treatments. Experimental cancer treatments are normally available only to people who participate in formal research programs, which are called clinical trials. Occasionally, a seriously ill person may be able to access an experimental drug through an expanded access program. Some of the treatments have regulatory approval for treating other conditions. Health insurance and publicly funded health care programs normally refuse to pay for experimental cancer treatments.
p53, also known as Tumor protein P53, cellular tumor antigen p53, or transformation-related protein 53 (TRP53) is a regulatory protein that is often mutated in human cancers. The p53 proteins are crucial in vertebrates, where they prevent cancer formation. As such, p53 has been described as "the guardian of the genome" because of its role in conserving stability by preventing genome mutation. Hence TP53 is classified as a tumor suppressor gene.
Bcl-2, encoded in humans by the BCL2 gene, is the founding member of the Bcl-2 family of regulator proteins that regulate cell death (apoptosis), by either inhibiting (anti-apoptotic) or inducing (pro-apoptotic) apoptosis. It was the first apoptosis regulator identified in any organism.
The apoptosome is a large quaternary protein structure formed in the process of apoptosis. Its formation is triggered by the release of cytochrome c from the mitochondria in response to an internal (intrinsic) or external (extrinsic) cell death stimulus. Stimuli can vary from DNA damage and viral infection to developmental cues such as those leading to the degradation of a tadpole's tail.
Betulinic acid is a naturally occurring pentacyclic triterpenoid which has antiretroviral, antimalarial, and anti-inflammatory properties, as well as a more recently discovered potential as an anticancer agent, by inhibition of topoisomerase. It is found in the bark of several species of plants, principally the white birch from which it gets its name, but also the ber tree, selfheal, the tropical carnivorous plants Triphyophyllum peltatum and Ancistrocladus heyneanus, Diospyros leucomelas, a member of the persimmon family, Tetracera boiviniana, the jambul, flowering quince, rosemary, and Pulsatilla chinensis.
Apoptosis regulator BAX, also known as bcl-2-like protein 4, is a protein that in humans is encoded by the BAX gene. BAX is a member of the Bcl-2 gene family. BCL2 family members form hetero- or homodimers and act as anti- or pro-apoptotic regulators that are involved in a wide variety of cellular activities. This protein forms a heterodimer with BCL2, and functions as an apoptotic activator. This protein is reported to interact with, and increase the opening of, the mitochondrial voltage-dependent anion channel (VDAC), which leads to the loss in membrane potential and the release of cytochrome c. The expression of this gene is regulated by the tumor suppressor P53 and has been shown to be involved in P53-mediated apoptosis.
Adenovirus E1B protein usually refers to one of two proteins transcribed from the E1B gene of the adenovirus: a 55kDa protein and a 19kDa protein. These two proteins are needed to block apoptosis in adenovirus-infected cells. E1B proteins work to prevent apoptosis that is induced by the small adenovirus E1A protein, which stabilizes p53, a tumor suppressor.
The BH3 interacting-domain death agonist, or BID, gene is a pro-apoptotic member of the Bcl-2 protein family. Bcl-2 family members share one or more of the four characteristic domains of homology entitled the Bcl-2 homology (BH) domains, and can form hetero- or homodimers. Bcl-2 proteins act as anti- or pro-apoptotic regulators that are involved in a wide variety of cellular activities.
The p53 upregulated modulator of apoptosis (PUMA) also known as Bcl-2-binding component 3 (BBC3), is a pro-apoptotic protein, member of the Bcl-2 protein family. In humans, the Bcl-2-binding component 3 protein is encoded by the BBC3 gene. The expression of PUMA is regulated by the tumor suppressor p53. PUMA is involved in p53-dependent and -independent apoptosis induced by a variety of signals, and is regulated by transcription factors, not by post-translational modifications. After activation, PUMA interacts with antiapoptotic Bcl-2 family members, thus freeing Bax and/or Bak which are then able to signal apoptosis to the mitochondria. Following mitochondrial dysfunction, the caspase cascade is activated ultimately leading to cell death.
Phorbol-12-myristate-13-acetate-induced protein 1 is a protein that in humans is encoded by the PMAIP1 gene, and is also known as Noxa.
Survivin, also called baculoviral inhibitor of apoptosis repeat-containing 5 or BIRC5, is a protein that, in humans, is encoded by the BIRC5 gene.
Bcl-2 homologous antagonist/killer is a protein that in humans is encoded by the BAK1 gene on chromosome 6. The protein encoded by this gene belongs to the BCL2 protein family. BCL2 family members form oligomers or heterodimers and act as anti- or pro-apoptotic regulators that are involved in a wide variety of cellular activities. This protein localizes to mitochondria, and functions to induce apoptosis. It interacts with and accelerates the opening of the mitochondrial voltage-dependent anion channel, which leads to a loss in membrane potential and the release of cytochrome c. This protein also interacts with the tumor suppressor P53 after exposure to cell stress.
The BCL2 associated agonist of cell death (BAD) protein is a pro-apoptotic member of the Bcl-2 gene family which is involved in initiating apoptosis. BAD is a member of the BH3-only family, a subfamily of the Bcl-2 family. It does not contain a C-terminal transmembrane domain for outer mitochondrial membrane and nuclear envelope targeting, unlike most other members of the Bcl-2 family. After activation, it is able to form a heterodimer with anti-apoptotic proteins and prevent them from stopping apoptosis.
B-cell lymphoma-extra large (Bcl-xL), encoded by the BCL2-like 1 gene, is a transmembrane molecule in the mitochondria. It is a member of the Bcl-2 family of proteins, and acts as an anti-apoptotic protein by preventing the release of mitochondrial contents such as cytochrome c, which leads to caspase activation and ultimately, programmed cell death.
Bcl-2-like protein 1 is a protein encoded in humans by the BCL2L1 gene. Through alternative splicing, the gene encodes both of the human proteins Bcl-xL and Bcl-xS.
Induced myeloid leukemia cell differentiation protein Mcl-1 is a protein that in humans is encoded by the MCL1 gene.
Azurin is a small, periplasmic, bacterial blue copper protein found in Pseudomonas, Bordetella, or Alcaligenes bacteria. Azurin moderates single-electron transfer between enzymes associated with the cytochrome chain by undergoing oxidation-reduction between Cu(I) and Cu(II). Each monomer of an azurin tetramer has a molecular weight of approximately 14kDa, contains a single copper atom, is intensively blue, and has a fluorescence emission band centered at 308 nm.
miR-31 has been characterised as a tumour suppressor miRNA, with its levels varying in breast cancer cells according to the metastatic state of the tumour. From its typical abundance in healthy tissue is a moderate decrease in non-metastatic breast cancer cell lines, and levels are almost completely absent in mouse and human metastatic breast cancer cell lines. Mir-31-5p has also been observed upregulated in Zinc Deficient rats compared to normal in ESCC and in other types of cancers when using this animal model. There has also been observed a strong encapsulation of tumour cells expressing miR-31, as well as a reduced cell survival rate. miR-31's antimetastatic effects therefore make it a potential therapeutic target for breast cancer. However, these two papers were formally retracted by the authors in 2015.
Paraptosis is a type of programmed cell death, morphologically distinct from apoptosis and necrosis. The defining features of paraptosis are cytoplasmic vacuolation, independent of caspase activation and inhibition, and lack of apoptotic morphology. Paraptosis lacks several of the hallmark characteristics of apoptosis, such as membrane blebbing, chromatin condensation, and nuclear fragmentation. Like apoptosis and other types of programmed cell death, the cell is involved in causing its own death, and gene expression is required. This is in contrast to necrosis, which is non-programmed cell death that results from injury to the cell.