TY - JOUR
T1 - Rab11-FIP1C is a critical negative regulator in ErbB2-mediated mammary tumor progression
AU - Boulay, Pierre Luc
AU - Mitchell, Louise
AU - Turpin, Jason
AU - Huot-Marchand, Julie Émilie
AU - Lavoie, Cynthia
AU - Sanguin-Gendreau, Virginie
AU - Jones, Laura
AU - Mitra, Shreya
AU - Livingstone, Julie M.
AU - Campbell, Shirley
AU - Hallett, Michael
AU - Mills, Gordon B.
AU - Park, Morag
AU - Chodosh, Lewis
AU - Strathdee, Douglas
AU - Norman, Jim C.
AU - Muller, William J.
N1 - Publisher Copyright:
© 2016 American Association for Cancer Research.
PY - 2016/5/1
Y1 - 2016/5/1
N2 - Rab coupling protein (FIP1C), an effector of the Rab11 GTPases, including Rab25, is amplified and overexpressed in 10% to 25% of primary breast cancers and correlates with poor clinical outcome. Rab25 is also frequently silenced in triplenegative breast cancer, suggesting its ability to function as either an oncogene or a tumor suppressor, depending on the breast cancer subtype. However, the pathobiologic role of FIP family members, such as FIP1C, in a tumor-specific setting remains elusive. In this study, we used ErbB2 mouse models of human breast cancer to investigate FIP1C function in tumorigenesis. Doxycycline-induced expression of FIP1C in the MMTV-ErbB2 mouse model resulted in delayed mammary tumor progression. Conversely, targeted deletion of FIP1C in the mammary epithelium of an ErbB2 model coexpressing Cre recombinase led to accelerated tumor onset. Genetic and biochemical characterization of these FIP1C-proficient and -deficient tumor models revealed that FIP1C regulated E-cadherin (CDH1) trafficking and ZONAB (YBX3) function in Cdk4-mediated cell-cycle progression. Furthermore, we demonstrate that FIP1C promoted lysosomal degradation of ErbB2. Consistent with our findings in the mouse, the expression of FIP1C was inversely correlated with ErbB2 levels in breast cancer patients. Taken together, our findings indicate that FIP1C acts as a tumor suppressor in the context of ErbB2-positive breast cancer and may be therapeutically exploited as an alternative strategy for targeting aberrant ErbB2 expression.
AB - Rab coupling protein (FIP1C), an effector of the Rab11 GTPases, including Rab25, is amplified and overexpressed in 10% to 25% of primary breast cancers and correlates with poor clinical outcome. Rab25 is also frequently silenced in triplenegative breast cancer, suggesting its ability to function as either an oncogene or a tumor suppressor, depending on the breast cancer subtype. However, the pathobiologic role of FIP family members, such as FIP1C, in a tumor-specific setting remains elusive. In this study, we used ErbB2 mouse models of human breast cancer to investigate FIP1C function in tumorigenesis. Doxycycline-induced expression of FIP1C in the MMTV-ErbB2 mouse model resulted in delayed mammary tumor progression. Conversely, targeted deletion of FIP1C in the mammary epithelium of an ErbB2 model coexpressing Cre recombinase led to accelerated tumor onset. Genetic and biochemical characterization of these FIP1C-proficient and -deficient tumor models revealed that FIP1C regulated E-cadherin (CDH1) trafficking and ZONAB (YBX3) function in Cdk4-mediated cell-cycle progression. Furthermore, we demonstrate that FIP1C promoted lysosomal degradation of ErbB2. Consistent with our findings in the mouse, the expression of FIP1C was inversely correlated with ErbB2 levels in breast cancer patients. Taken together, our findings indicate that FIP1C acts as a tumor suppressor in the context of ErbB2-positive breast cancer and may be therapeutically exploited as an alternative strategy for targeting aberrant ErbB2 expression.
UR - http://www.scopus.com/inward/record.url?scp=84969674110&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84969674110&partnerID=8YFLogxK
U2 - 10.1158/0008-5472.CAN-15-2782
DO - 10.1158/0008-5472.CAN-15-2782
M3 - Article
C2 - 26933086
AN - SCOPUS:84969674110
SN - 0008-5472
VL - 76
SP - 2662
EP - 2674
JO - Cancer Research
JF - Cancer Research
IS - 9
ER -