Pharmacogenetics, Targeted Therapeutics, and Molecular Biotechnology

Comprehensive vocabulary flashcards generated from lecture transcript notes covering drug target pharmacogenetics, transport proteins, biotransformation, biological therapeutics, monoclonal antibody engineering, and molecularly targeted cancer therapy.

Promoter Single Nucleotide Polymorphism (Promoter SNP)

A single base-pair change in the regulatory region of a gene that alters transcript abundance, shifting an individual's placement on a continuous normal bell curve of gene expression without completely inactivating the gene product.

Beta-1 Receptor Position 389 Polymorphism

A functional genetic variation in the beta-1 adrenergic receptor where an arginine at position 389 produces strong cyclic AMP signaling and higher blood pressure, resulting in a significantly greater antihypertensive response to metoprolol compared to glycine at position 389.

Drug Name Suffix -olol

A standardized pharmacological naming ending that identifies drugs belonging to the class of beta-receptor antagonists or beta-blockers (e.g., metoprolol).

Drug Name Suffix -navir

A standardized pharmacological naming ending that identifies drugs belonging to the class of HIV protease inhibitors.

Reverse Transcriptase

An enzyme discovered by David Baltimore that transcribes viral genetic information from RNA to DNA, establishing an exception to the classical central dogma that genetic information flows exclusively from DNA to RNA to protein.

Highly Active Antiretroviral Therapy (HAART)

An HIV treatment combination regimen consisting of two to three nucleoside analogues, one or two protease inhibitors, and one reverse transcriptase inhibitor to maximize viral suppression and minimize host toxicity.

Chemokines

A family of small ($8\text{ to }10\,kDa$) chemotactic cytokines categorized by their cysteine residues (CC, CXC, CXXXC, C) that bind G-protein coupled receptors to direct immune cell migration.

CCR5 Deletion Mutation

A genetic deletion in the chemokine receptor CCR5 gene that confers substantial protection against HIV infection by preventing the virus from using CCR5 as an entry co-receptor alongside CD4.

Theranostics

The clinical practice of co-developing a molecularly targeted therapeutic agent alongside its companion diagnostic test (such as Herceptin paired with the Herceptest for HER2-overexpressing breast cancer) to select responsive patient populations.

Genostratification

The process of using genetic and molecular testing to screen and stratify clinical trial participants, targeted toward enrolling likely responders and excluding individuals at high risk for drug toxicity.

ABCB1 (PGP / MDR1)

ATP-binding cassette sub-family B member 1 (also termed P-glycoprotein or Multidrug Resistance 1), a critical ATP-dependent efflux transporter localized in excretory tissues and physiological barrier membranes.

Substrate Promiscuity

The property of broad, loosely defined substrate specificity displayed by major transport proteins (such as ABCB1) and metabolizing enzymes (such as Cytochrome P450s), allowing them to process a wide spectrum of hydrophobic and amphipathic xenobiotics.

Digoxin and Quinidine Interaction

A competitive drug interaction occurring on ABCB1/PGP transporters where quinidine administration leads to a two- to three-fold increase in plasma digoxin concentrations.

Digoxin and Rifampin Interaction

A drug interaction in which rifampin upregulates cellular ABCB1/PGP expression, resulting in enhanced efflux and therapeutic failure of co-administered digoxin.

Blood-Brain Barrier (BBB) Structural Components

A protective central nervous system structure comprising capillary endothelial cells joined by tight junctions and surrounded by astrocyte foot processes (podocytes), utilizing asymmetric transporter distribution to limit central drug uptake.

Blood-Testis Barrier (BTB)

A physical barrier established by tight junctions between Sertoli cells that shields maturing sperm in seminiferous tubules from blood-borne toxins and isolates them from autoimmune surveillance.

Placental Barrier Molecular Weight Threshold

The general physiological threshold where small compounds weighing under $500\text{ Daltons}$ cross the placenta relatively unimpeded by passive diffusion, whereas larger molecules display incomplete placental transfer.

Phase 1 Biotransformation

The first phase of hepatic drug biotransformation that introduces or unmasks polar functional groups on xenobiotics to increase water solubility.

Phase 2 Biotransformation

The second phase of drug biotransformation that attaches small endogenous polar molecules to functionalized sites on xenobiotics to facilitate systemic elimination.

Cytochrome P450 (CYP) Peak Absorbance

The characteristic spectrophotometric absorption peak at $450\,nm$ exhibited by CYP enzymes due to the central iron-protoporphyrin (heme carbon) catalytic domain.

Debrisoquine

A probe compound metabolized by CYP2D6 used clinically and experimentally to measure metabolic clearance rates and classify patients into poor, intermediate, extensive, or ultra-rapid metabolizers.

Nortriptyline Dosing Risk

A therapeutic challenge in managing severe depression with nortriptyline (a CYP2D6 substrate), where treatment restores physical impetus prior to improving mood, creating a critical high-risk window for suicide.

AmpliChip

A microarray DNA diagnostic chip designed to genotype individual CYP gene polymorphisms, which saw limited clinical implementation due to a lack of actionable clinical algorithms connecting genotypes to dosing choices.

High-Throughput Screening

A drug discovery methodology that rapidly screens massive combinatorial chemical libraries (millions of compounds) against target molecules to isolate rare, high-affinity interaction leads without requiring prior structural information.

Rational Drug Design

A deterministic drug development approach that utilizes detailed three-dimensional protein structures (obtained via X-ray crystallography, NMR, cryo-EM, or computational tools like AlphaFold) to optimize drug structures for specific binding pockets, such as dihydrofolate reductase.

Plasmid

A small, circular, extrachromosomal DNA molecule utilized in recombinant DNA technology as a vector to clone and insert target genes into bacterial hosts.

Ampicillin Resistance Gene Selection

A molecular selection strategy where an ampicillin resistance gene is co-incorporated onto a vector plasmid, allowing only successfully transformed host bacteria to survive exposure to ampicillin.

E. coli as an Expression Host

A rapid and inexpensive bacterial host system for recombinant protein production, limited by its inability to perform eukaryotic post-translational modifications, lack of protein secretion, and tendency to fold complex proteins into non-functional lowest-energy states.

Mammalian Cells as an Expression Host

A recombinant expression system that provides correct protein folding and complex eukaryotic post-translational modifications, but requires expensive growth media, exhibits slow doubling times, and carries risks of co-purifying mammalian pathogens or prions.

Biosimilars

Biological therapeutics manufactured in living systems that are highly similar but non-identical to an approved reference biologic, requiring a specialized regulatory pathway distinct from small-molecule generic drugs.

Hybridoma Technology

A monoclonal antibody production method pioneered by Georges Köhler and César Milstein that fuses a single, specific antibody-producing B cell with an immortal myeloma cell.

Human Anti-Mouse Antibody (HAMA) Response

An unwanted human immune response mounted against injected murine-derived antibodies, leading to rapid antibody neutralization and severe loss of therapeutic efficacy upon repeated administration.

Monoclonal Antibody Nomenclature Suffix -mab

The mandatory standardized suffix used at the end of non-trade drug names to denote that the drug is a monoclonal antibody.

Chimeric Monoclonal Antibody (-ximab)

An engineered monoclonal antibody containing mouse variable Fab regions attached to human constant Fc regions, resulting in approximately 70% human sequence content (e.g., Infliximab).

Humanized Monoclonal Antibody (-zumab)

An engineered antibody constructed by grafting murine complementarity-determining regions (CDRs) into a human immunoglobulin framework, yielding approximately 90% human sequence content (e.g., Trastuzumab).

Fully Human Monoclonal Antibody (-umab)

A therapeutic antibody derived entirely from human gene sequences, containing 100% human amino acid sequence composition (e.g., Adalimumab).

Trastuzumab (Herceptin)

A humanized monoclonal antibody targeting HER2 that prevents receptor dimerization and blocks growth signal transduction in HER2-overexpressing breast cancers.

HER2 (Human Epidermal Growth Factor Receptor 2)

A receptor tyrosine kinase member of the EGF receptor family that is pathologically overexpressed in approximately 20-25% of human breast cancers.

Etanercept (Enbrel)

A engineered fusion protein combining the extracellular ligand-binding domain of the human TNF receptor with the Fc portion of human IgG, forming a dimeric decoy receptor that scavenges soluble TNF-alpha.

Anakinra (Kineret)

A recombinant form of the endogenous human interleukin-1 receptor antagonist (IL-1Ra) used to block IL-1 signaling and slow joint degradation in rheumatoid arthritis.

Philadelphia Chromosome

An abnormal chromosome generated by a reciprocal translocation between chromosomes 9 and 22 ($t(9;22)$), serving as a characteristic genetic hallmark of chronic myelogenous leukemia (CML).

BCR-ABL Fusion Protein

An oncogenic chimeric protein created by placing the Breakpoint Cluster Region (BCR) gene upstream of the Abelson (ABL) kinase gene, breaking the enzyme's internal off-switch and triggering constitutive kinase signaling.

Imatinib Mesylate (Gleevec)

A pioneering small-molecule tyrosine kinase inhibitor developed by Brian Drucker that competitively binds the ATP-binding pocket of the BCR-ABL fusion protein to treat chronic myelogenous leukemia (CML).

Gefitinib (Iressa)

A small-molecule EGFR tyrosine kinase inhibitor that selectively targets the L858R kinase domain point mutation at position 858, a mutation that pried open the catalytic domain in non-smoking lung cancer patients.

EGFR Inhibitor Class Side Effect

A mandatory class-wide adverse effect associated with drugs that inhibit epidermal growth factor receptors, presenting clinically as severe cutaneous skin rashes.