The two-dimensional kagome spin lattice structure of Mn atoms in the family of Mn3X noncollinear antiferromagnets are providing substantial excitement in the exploration of Berry-curvature physics and the associated nontrivial magnetotransport responses. Much of these studies are performed in the hexagonal systems, mainly Mn3Sn and Mn3Ge with the kagome planes having their normal along the  direction. In this paper, we report our study in the cubic Mn3Pt thin films with their kagome planes normal to the  crystal axis. Our studies reveal a hole conduction dominant Hall response with a non-monotonic temperature dependence of anomalous Hall conductivity (AHC), increasing from 9ω-1cm-1 at room temperature to 29ω-1cm-1 at 100 K, followed by a drop and unexpected sign reversal at lower temperatures. Similar sign reversal is also observed in magnetoresistance measurements. We attribute this sign reversal to the transition from a Berry-curvature-dominated AHC at high temperature to a weak canted ferromagnetic AHC response at lower temperatures below 70 K caused by the reorientation of Mn moments out of the kagome plane. Our above results in thin films of Mn3Pt make advances in their integration with room-temperature antiferromagnetic spintronics. © 2021 American Physical Society.