With the large increases in video content, mobile network operators (MNOs) are persistently seeking to lower their content access latency and backhaul traffic. To mitigate these challenges, operators have started developing an operator-owned content caching system. However, in such networks, it is difficult to provide cost-effective and reliable cache performance for dynamically changing traffic using traditional proprietary network equipment. Meanwhile, network function virtualization (NFV) technology has become a key enabler in providing new business models with reduced costs and enhanced service agility to mobile networks. In addition, dynamic scaling of virtualized network functions can be used to leverage adaptable management of network services on the fly. In this study, we introduce a system architecture of an MNO-driven virtualized caching-service based on an NFV standard platform that uses an integer linear programming (ILP)-based centralized optimization algorithm. Our proposed system employs mainly two techniques: a hierarchical caching model and a hybrid (centralized and distributed) orchestration scheme to optimize cache function with fine-grained control. Through experiments, we show that the conceptual MNO caching service is an effective strategy for reducing the traffic burden and enhancing the quality of service (QoS) for streaming video.