Journal: Nature cell biology
Article Title: Pancreatic cancer cells upregulate LPAR4 in response to isolation stress to promote an ECM-enriched niche and support tumor initiation
doi: 10.1038/s41556-022-01055-y
Figure Lengend Snippet: a, Immunohistochemistry staining of LPAR4 in a PDAC tissue array consisted of 15 PDAC samples and 4 samples of normal pancreas. Scale bar is 50 μM. Representative images showing normal pancreas (n=4 biological samples), low-LPAR4 PDAC (n=9 biological samples), and high-LPAR4 PDAC (n=6 biological samples). Bar graph shows the relative percentage of LPAR4-low and LPAR4-high patients in the PDAC tissue array. b, Quantitative RT-PCR confirming the manipulation of LPAR4 expression in 2 pancreatic cancer cell lines (Colo-357, MIA PaCa-2) and 2 patient-derived cancer cells (79E, 34E). Data were shown as mean ± s.d. (n=4 independent experiments for Colo-357 and 79E cells with LPAR4 stable knockdown, n=3 for Colo-357, 79E, and MiaPaCa2 cells with LPAR4 ectopic expression, n=3 for 34E cells with LPAR4 stable knockdown, and n=4 for 34E with LPAR4 ectopic expression). c, Non-invasive Bioluminescence images showing tumors formed at day 10 for Colo-357+sh-CTRL+luciferase or Colo-357+sh-R4.1+luciferase of various number implanted in the pancreas of nu/nu mice. Right panel showing the luminescence intensity in a blue-to-red spectrum. d, f, Trypan blue exclusion assay showing the relative number of viable cells with or without LPAR4 expression manipulation grown in 10% serum and 2D at day 4 and day 7. e, Tumor growth rates for 1 million Colo-357 cells with or without LPAR4 expression manipulation in a subcutaneous tumor model. Data were presented as mean ± s.d. for n=8 independent samples for each group. g, Quantitative RT-PCR confirming the knockdown of LPAR1 in Colo-357 cells. h, Effects of LPAR1 knockdown using siRNA on 2D or 3D (methylcellulose sphere forming) cell growth. Data were presented as mean ± s.d. for n=3 independent experiments (d,f,g, and h). Statistical analyses were performed using two tailed unpaired one sample t-test (b,g, and h) and one-way ANOVA (d-f). Source numerical data are available in source data.
Article Snippet: Immunohistochemistry staining of LPAR4 or FN1 in human PDAC tissue array (US Biomax PA484a) or formalin-fixed, paraffin-embedded xenograft tumors were performed using the LPAR4 antibody (Thermo Fisher, #PA5–49727) or FN1 antibody (CST, #26836, E5H6X) following the manufacturer’s protocol.
Techniques: Immunohistochemistry, Staining, Quantitative RT-PCR, Expressing, Derivative Assay, Luciferase, Trypan Blue Exclusion Assay, Two Tailed Test