Stretching inhibits tumor growth in MMTV-PYMT via a direct mechanical effect

Background: Tumor-associated architecture and emerging mechanical properties (forces, pressure, tension, stiffness) affect the growth and invasiveness of cancer cells. Collagen fibers aligned perpendicular to the boundaries of tumors promote local tumor invasiveness in mouse mammary tumor models and are associated with a poor prognosis in human breast cancer. Our previous study revealed that daily gentle stretching (~25% strain) for 10 min reduced the growth of P53/PTEN-/- orthotopic mouse mammary tumors by 50%.
Results: In this study, we further investigated the mechanism of stretching in a more aggressive MMTV-PYMT (mammary tumor virus-polyomavirus middle T antigen) tumor model in vivo and in vitro and analyzed its impact on collagen reorganization at both the tumor-stromal interface and the tumor microenvironment composition at single cell level. Stretching reduced the average tumor size by 30–50% in orthotopic (Active and Passive Stretch) and transgenic (Passive Stretch) models. In ..., Berrueta et al tumors collagen signature Data  092624: data was collected from images taken by confocal second harmonic generation microscopy and analyzed using the CurveAlign sofware
Berrueta et al Orthotopic active stretch Master file  72623: data was collected by weekly measurements of the tumor using caliper and 3D ultrasound and procceced with the VevoLab sofware  
Berrueta et al Orthotopic model Passive stretch master file 61223: data was collected by weekly measurements of the tumor using caliper and 3D ultrasound and procceced with the VevoLab sofware 
Berrueta et al  qPCR data from Orthotopic active stretch Master file _Batch 16-18   062323: data was collected by homogenizing the tumors after euthanasia, then extracting RNA and running qPCR for gene expression 
Berrueta et al  qPCR Orthotopic passive stretch Master file Batch   071823: data was collected by homogenizing the tumors after euthanasia, then extracting RNA and runnin..., , # Stretching inhibits tumor growth in MMTV-PYMT via a direct mechanical effect

Dataset DOI: [10.5061/dryad.1rn8pk13r](https://doi.org/10.5061/dryad.1rn8pk13r)

## Description of the data and file structure

**Berrueta_et_al__qPCR_Orthotopic_passive_stretch_Master_file_Batch___071823.csv**

The data include 13 columns: column A is Animal Identification (ID); column B is batch number, column C; is condition: 1=Stretch, 0= No stretch; column D is relative gene expression for collagen 1a1 (Col1a1); column E is relative gene expression for Collagen 5a2 (Col5a2); column F is relative gene expression for Collagen 6a2 (Col6a2); Column G is relative gene expression for Actin Alpha 2, Smooth Muscle (a-SMA), Column H is relative gene expression for Transforming Growth Factor Beta (TGF-b); Column I is relative gene expression for connexin-43; Column J is relative gene expression for Piezo; Column K is relative gene expression for Discoidin Domain Receptor 1 (Ddr1); Column L is relative gene expres...,