  Energies of the giant Gamow-Teller and analog resonances - $E_{\rm G}$ and
$E_{\rm A}$, are presented, calculated using the microscopic theory of finite
Fermi system. The calculated differences $\Delta E_{\rm G-A}=E_{\rm G}-E_{\rm
A}$ go to zero in heavier nuclei indicating the restoration of Wigner
SU(4)-symmetry. The calculated $\Delta E_{\rm G-A}$ values are in good
agreement with the experimental data. The average deviation is 0.30 MeV for the
33 considered nuclei for which experimental data is available. The $\Delta
E_{\rm G-A}$ values were calculated for heavy and superheavy nuclei up to the
mass number $A $= 290. Using the experimental data for the analog resonances
energies, the isotopic dependence of the difference of the Coulomb energies of
neighboring nuclei isobars analyzed within the SU(4)-approach for more than 400
nuclei in the mass number range of $A$ = 3 - 244. The Wigner SU(4)-symmetry
restoration for heavy and superheavy nuclei is confirmed. It is shown that the
restoration of SU(4)-symmetry does not contradict the possibility of the
existence of the "island of stability" in the region of superheavy nuclei.
