PITPNM3 Antibody

What is PITPNM3 and what is its biological function?

PITPNM3, also known as Pyk2 N-terminal domain-interacting receptor 1 (NIR-1), catalyzes the transfer of phosphatidylinositol and phosphatidylcholine between membranes in vitro and binds calcium ions . It functions as a peripheral membrane protein within the endomembrane system . Recent research has identified PITPNM3 as playing significant roles in tumor invasion and metastasis, particularly in hepatocellular carcinoma and breast cancer cells .

Which applications are PITPNM3 antibodies validated for?

Commercial PITPNM3 antibodies have been validated for multiple research applications:

When selecting an antibody, researchers should verify specific application validations and optimal conditions for their experimental systems .

What tissue expression pattern does PITPNM3 exhibit?

Immunohistochemical analyses using validated PITPNM3 antibodies have demonstrated expression across multiple human tissues including:

• Human spleen

• Human kidney

• Human liver

• Human cerebral cortex

• Human pancreas (showing lower expression)

• Human epithelial cell lines (e.g., HeLa cells)

This broad expression pattern suggests PITPNM3 may have fundamental cellular functions, while its upregulation in specific cancer contexts indicates potential specialized roles in disease states .

What are the recommended validation approaches for PITPNM3 antibodies?

Thorough antibody validation is essential for reliable PITPNM3 research. Recommended approaches include:

• Western blot analysis: Verify detection of bands at the expected molecular weight using positive control lysates

• Genetic knockdown validation: Compare antibody signal between wild-type cells and those with PITPNM3 knockdown (siRNA) or knockout (CRISPR/Cas9)

• Recombinant protein controls: Some antibodies target specific regions (e.g., aa 450-600 or aa 563-613) that can be used as positive controls

• Cross-reactivity testing: If the antibody claims reactivity with multiple species (human/mouse), validation should be performed in each species

• Immunohistochemistry pattern analysis: Compare staining patterns with known expression data from multiple tissues

What controls should be included when working with PITPNM3 antibodies?

Robust experimental design requires multiple controls:

• Negative controls: Isotype control (rabbit IgG for rabbit polyclonal antibodies) to assess non-specific binding

• Positive controls: Tissues or cell lines with confirmed PITPNM3 expression (e.g., HeLa cells, liver tissue)

• Loading controls: For Western blot applications, β-Actin (ACTB) has been successfully used as a housekeeping control gene

• Specificity controls: Cells with PITPNM3 knockdown provide critical validation of antibody specificity

How should PITPNM3 antibodies be stored and handled for optimal performance?

Based on commercial product information, researchers should follow these storage guidelines:

• Store antibodies at -20°C for up to 1 year from receipt

• Avoid repeated freeze-thaw cycles to maintain antibody integrity

• Commercial antibodies are typically formulated in PBS containing glycerol (50%), BSA (0.5%), and sodium azide (0.02%)

• Prepare working dilutions fresh before use and store at 4°C for short-term applications

How does PITPNM3 contribute to cancer progression and metastasis?

PITPNM3 has emerged as a significant factor in cancer biology through several mechanisms:

• Receptor for CCL18: PITPNM3 functions as a receptor for CC-chemokine ligand 18 (CCL18) in hepatic carcinoma cells. This interaction activates downstream signaling pathways related to cell adhesion, enhancing invasion and metastasis .

• Tumor growth promotion: Tumorigenicity assays in nude mice demonstrated that PITPNM3 upregulation resulted in larger tumor volumes, while silencing PITPNM3 expression markedly attenuated the invasive and metastatic abilities of hepatocellular carcinoma cells .

• Conserved metastasis-promoting effect: Similar findings have been observed in breast cancer cells, suggesting PITPNM3's role in metastasis extends across multiple cancer types .

These findings collectively position PITPNM3 as a potential therapeutic target for preventing cancer metastasis, particularly in HCC and breast cancer.

What is the regulatory relationship between PITPNM3, SP1, and Mfn-2 in cancer cells?

Research has elucidated a regulatory pathway involving PITPNM3, the transcription factor SP1, and Mitofusin-2 (Mfn-2) in cancer regulation:

• SP1 as transcriptional activator: SP1 was identified as a transcription factor for PITPNM3 with numerous binding sites in the PITPNM3 promoter region. Upregulation of SP1 results in elevated PITPNM3 expression .

• Mfn-2 as negative regulator: Co-immunoprecipitation (Co-IP) assays demonstrated that Mfn-2 interacts directly with SP1 protein. This interaction suppresses SP1's binding to the PITPNM3 promoter, as confirmed by Chromatin immunoprecipitation (ChIP) assays .

• Opposing effects on tumorigenesis: In nude mice models, SP1 and PITPNM3 transfection resulted in larger tumors, while Mfn-2 transfection led to smaller tumors. This suggests SP1 and PITPNM3 promote tumor development, while Mfn-2 exhibits anti-tumor activity .

• Mechanistic pathway: The research establishes a regulatory cascade where Mfn-2 suppresses PITPNM3 expression by interfering with SP1's transcriptional activity, ultimately inhibiting tumor development .

This regulatory pathway provides insights into potential therapeutic approaches targeting this signaling axis in cancer treatment.

How can PITPNM3 expression be effectively silenced for functional studies?

For functional studies investigating PITPNM3's role, several gene silencing approaches can be employed:

Validation of silencing effectiveness should include:

• qRT-PCR to measure mRNA reduction using appropriate primers and reference genes like β-Actin

• Western blot analysis using validated PITPNM3 antibodies

• Functional assays relevant to PITPNM3's role (cell migration, invasion assays)

What techniques can be used to study PITPNM3 interactions with other proteins?

Several methods can be employed to investigate PITPNM3 protein interactions:

• Co-immunoprecipitation (Co-IP): Successfully used in PITPNM3 research to demonstrate protein interactions, such as those between Mfn-2 and SP1 . This approach can be applied to study PITPNM3's interaction with CCL18 and other binding partners.

• Chromatin Immunoprecipitation (ChIP): Effective for studying transcription factor interactions with the PITPNM3 promoter, as demonstrated in research examining SP1 binding .

• Proximity ligation assay (PLA): Enables visualization of protein-protein interactions in situ using antibodies against PITPNM3 and potential interacting partners.

• Recombinant protein studies: Expression of PITPNM3 domains for in vitro binding assays with purified interaction partners can define specific binding regions.

These complementary approaches provide powerful tools for establishing and characterizing the protein interaction network of PITPNM3.

How can PITPNM3 be evaluated as a potential biomarker in cancer research?

Based on current research findings, PITPNM3 shows promise as a biomarker in cancer:

• Expression correlation with progression: Studies have demonstrated elevated PITPNM3 expression in hepatocellular carcinoma tissues compared to normal tissues .

• Methodological approaches for validation:

  • Immunohistochemistry analysis of tissue microarrays using validated antibodies

  • Correlation of expression levels with clinical parameters (tumor size, stage, metastasis)

  • Real-time PCR quantification in research settings

• Potential applications:

  • Diagnostic biomarker: Distinguishing malignant from benign tissues

  • Prognostic biomarker: Predicting patient outcomes based on expression levels

  • Therapeutic target: The regulatory pathway involving Mfn-2, SP1, and PITPNM3 offers multiple intervention points

What are the challenges in distinguishing PITPNM3 from other PITPNM family members?

The PITPNM family includes several related proteins that share structural and functional similarities, creating specific research challenges:

• Antibody specificity: Using antibodies targeting unique regions of PITPNM3 (e.g., aa 450-600 or aa 563-613) is essential for avoiding cross-reactivity .

• Validation strategies:

  • Western blot analysis should confirm bands at the expected molecular weight

  • Genetic knockdown/knockout models provide crucial specificity validation

  • Immunoprecipitation followed by mass spectrometry can confirm capture of the specific family member

• Primer design for qPCR studies:

  • Design primers targeting unique regions of PITPNM3 mRNA

  • Validate primer specificity using appropriate controls