Molecule guides
Oncology Research Reagents: Peptide Families, Antisera and Kits in the Cancer Catalog
How the cancer topic is organised: which families belong to it, what each reagent is ordered for, and how to match format, species and label chemistry to your assay.
The oncology peptides and antibodies we list serve four separate purposes. A few provide receptor and checkpoint ligands for immuno-oncology experiments; others intervene in blood-vessel formation; others again serve as calibrators for quantitative immunoassays against tumour markers; and a final set are substrates cleaved by proteases in invasion studies. Arranged by parent molecule, the cancer topic page brings together the antisera, peptide standards, kits and labelled tracers laboratories order for this work. Below: which families the topic holds, the reason each is bought, and the reagent format that answers each kind of question.
What the cancer topic includes
Products are grouped by how they are used experimentally, not by any claim about clinical activity. A family belongs in this topic when oncology research treats the parent peptide or protein as a recognised marker, target or laboratory tool — which brings in the checkpoint proteins, regulators of blood-vessel growth, gastrointestinal hormones whose receptors are known to be mitogenic on tumour lines, proteases implicated in matrix degradation, and the secreted markers used to stage or monitor disease in model systems. Several families appear in more than one topic: obesity research also covers adiponectin, and neuropeptide research also covers somatostatin. To be clear, nothing here is a treatment — every product exists purely for laboratory assays and approved animal studies.
Checkpoint and immuno-oncology reagents
A large share of current orders comes from checkpoint biology. Within these families you will find antisera for staining expression in tumour material, fragments of extracellular domains, and blocking peptides:
- PD-1 and PD-L1 — peptides covering the contact surface between the two proteins, used both as immunogens and in binding or competition assays, plus antisera for scoring stained sections of tumour.
- CTLA-4 — the other classical checkpoint route, offered as antibodies and standards for research into T-cell co-stimulation.
- TNF and the interleukins — cytokines and cytokine fragments for microenvironment work, which double as calibrators in multiplex assays.
- Chemokines from the CCL and CXCL families, SDF-1 (CXCL12) among them — applied wherever cell migration or homing to secondary sites is being followed; in the literature on tumour spread, few axes have drawn as much attention as CXCR4 and SDF-1.
Angiogenesis and its peptide inhibitors
No other area in this topic supplies as many peptide reagents, and the reason is structural: several of the body's own angiogenesis inhibitors turn out to be fragments released from larger matrix proteins.
- Endostatin — released from the C-terminal region of collagen XVIII and the canonical endogenous inhibitor of vessel growth; used in endothelial tube-formation and migration assays.
- Anginex — a designed beta-sheet peptide aimed at galectin-1 on the surface of activated endothelium; an engineered tool rather than a fragment of anything natural.
- Vasohibin and PEDF — inhibitory factors produced by endothelium itself, offered as calibration standards and for detection with antibodies.
- Thrombospondin — sequences derived from the type-1 repeats of TSP-1, the ABT-510 series among them, widely used as positive controls when screening for anti-angiogenic activity.
- Angiopoietin — reagents covering Tie2 signalling and Ang-1/Ang-2 for work on vessel stability; there is considerable overlap here with the cardiovascular section.
Markers, growth factors and invasion-related families
The families that remain split into two kinds: markers you quantify in a sample, and tools for interrogating a mechanism:
- Chromogranin A — the standard marker of neuroendocrine secretion, and one of the most frequently requested assay-kit targets anywhere in this topic.
- Gastrin and CCK — used to study CCK-B/gastrin receptor signalling in gastrointestinal tumour lines, and supplied both as complete peptides and as analogues selective for one receptor.
- Bombesin and gastrin-releasing peptide — central historically to work on autocrine growth loops in small-cell lung carcinoma, and still used when developing probes directed at GRPR.
- Somatostatin — SSTR subtype pharmacology underlies neuroendocrine tumour imaging as well as a large body of cell work on antiproliferative effects.
- Survivin together with the Bcl proteins — tools for apoptosis research, including BH3-domain peptides used to assess mitochondrial priming.
- uPAR, cathepsin and autotaxin — the invasion and matrix-degradation group, in which cathepsin substrates are normally ordered as fluorogenic labelled peptides.
- Osteopontin and glypican — adhesion and co-receptor proteins with recognised marker status, glypican-3 especially in hepatocellular models.
- TGF-β — promoter in some contexts and suppressor in others, with antisera and peptide standards supporting work on either interpretation.
Formats found in the cancer topic
Four kinds of product recur throughout these families. The workhorses are synthetic peptide standards — immunogens, receptor ligands and blocking peptides, generally supplied at ≥95% HPLC purity in fills from micrograms to milligrams. Labelled peptides count for more here than in other topics, because protease assays depend on FRET-based fluorogenic substrates and pull-down experiments depend on biotinylated ligands. Polyclonal antisera cover Western detection and staining of tumour sections. Secreted markers such as endostatin or chromogranin A are quantified in conditioned medium and plasma using EIA and ELISA kits. Immunoprecipitation and pull-down work additionally uses magnetic beads, and projects mapping epitopes use peptide libraries — a set of overlapping scans across a tumour antigen is an everyday request.
Choosing within a family
Three considerations come up again and again. Fragment or whole molecule? Checkpoint experiments almost always use peptides covering the binding interface rather than a complete ectodomain, and remember that a blocking peptide is validated for soaking up an antibody, not for receptor pharmacology. Which species? Syngeneic and xenograft mouse models need mouse-sequence reagents, and an antiserum raised against a human sequence should never be assumed to cross-react — species reactivity is stated on every item. Does it suit the assay? A fluorogenic substrate is characterised as much by its quenching chemistry and label pair as by its amino acids, so confirm the excitation and emission spectra match your plate reader before you order.
Handling notes specific to this topic
The majority of peptides in this topic are small, freeze-dried and stable for years while sealed at −20 °C. Two cautions matter more here than elsewhere. Hydrophobic sequences — a number of thrombospondin-derived and BH3 peptides among them — go into solution reluctantly in aqueous buffer and may need an organic co-solvent; peptide solubility explains the options. And because fluorogenic substrates are sensitive to light, aliquot them under dim light and store them in amber vials. For general practice see the storage and aliquoting guides, and the COA guide for verifying what you have received.
Where to look next
You can browse the whole cancer topic or begin at the research catalog hub. Also relevant: the cardiovascular section, which shares the vessel-growth families, and the assay kit type guide if your interest is in quantifying markers rather than probing mechanism.
Questions
Can any of these products treat cancer?
No, not one. Everything listed in this part of the catalogue is a reagent intended for in-vitro experiments and properly approved animal work. Certain families do have a history in clinical research — somatostatin analogues, thrombospondin-derived peptides, endostatin — but what we supply is not manufactured to pharmaceutical standards.
What does a blocking peptide do?
A blocking peptide is the immunogen sequence used to raise a given antiserum. Incubating the antibody with an excess of that peptide beforehand should abolish the specific signal, which is the conventional way to demonstrate specificity in Western blots and immunohistochemistry. It is strictly a control reagent, not a pharmacological agent; see the glossary definition of blocking peptides.
For a xenograft study, should reagents be human or mouse sequence?
It hinges on what you are measuring. Reagents based on the human sequence detect the implanted tumour; reagents based on the mouse sequence detect the vasculature, stroma and infiltrating immune cells of the host. Because the immune infiltrate and new vessels in a xenograft are supplied by the animal rather than the graft, mouse-sequence reagents are normally what you need — even though the tumour cells themselves are human.
Why do protease substrates come as labelled peptides?
Because the assay reads activity as a fluorescence change. In a fluorogenic substrate, a quencher sits on one side of the scissile bond and a fluorophore on the other; when the enzyme cuts, the two are separated and signal appears. That makes the choice of label pair every bit as important as the choice of sequence, so check that the excitation and emission wavelengths suit your reader. Our labelled peptides guide covers the available chemistries.
Which markers in this topic are better measured with a kit than with an antibody?
Anything that appears in serum, plasma or conditioned medium: endostatin, osteopontin, chromogranin A and a number of chemokines. A kit gives you a validated working range, calibration standards and an antibody pair known to work together, which is faster and far more repeatable than building the assay from components. For blotting or localising a target in tissue, individual antibodies remain the right tool.
Are BH3 peptides and other hydrophobic sequences stable in solution?
Less stable than a typical hydrophilic peptide, and more troublesome to dissolve in the first place. Many require DMSO or a comparable organic solvent before being taken into aqueous buffer, and they tend to aggregate if left standing. Where the assay allows it, make them up fresh, freeze single-use aliquots, and measure the concentration rather than assuming nothing was lost during filtration.