  We investigate possible renormalization effects on the low-energy mass
spectrum of the minimal supersymmetric standard model (MSSM), using a
calculable model of strongly coupled hidden sector. We model the hidden sector
by N=2 supersymmetric quantum chromodynamics with gauge group SU(2) x U(1) and
N_f=2 matter hypermultiplets, perturbed by a Fayet-Iliopoulos term which breaks
the supersymmetry down to N=0 on a metastable vacuum. In the hidden sector the
Kahler potential is renormalized. Upon identifying a hidden sector modulus with
the renormalization scale, and extrapolating to the strongly coupled regime
using the Seiberg-Witten solution, the contribution from the hidden sector to
the MSSM renormalization group flows is computed. For concreteness, we consider
a model in which the renormalization effects are communicated to the MSSM
sector via gauge mediation. In contrast to the perturbative toy examples of
hidden sector renormalization studied in the literature, we find that our
strongly coupled model exhibits rather intricate effects on the MSSM soft
scalar mass spectrum, depending on how the hidden sector fields are coupled to
the messenger fields. This model provides a concrete example in which the
low-energy spectrum of MSSM particles that are expected to be accessible in
collider experiments is obtained using strongly coupled hidden sector dynamics.
