To avoid cell cycle arrest or apoptosis, rapidly proliferating cancer cells have to promote DNA double strand break (DSB) repair to fix replication stress induced DSBs. Therefore, developing drugs blocking homologous recombination (HR) and nonhomologous end joining (NHEJ) - 2 major DSB repair pathways - holds great potential for cancer therapy. Over the last few decades, much attention has been paid to explore drugs targeting DSB repair pathways for cancer therapy. Here, using 2 well-established reporters for analyzing HR and NHEJ efficiency, we found that both HR and NHEJ are elevated in hepatoma cell lines Hep3B and HuH7 compared with normal liver cell lines Chang liver and QSG-7701. Our further study found that Harmine, a natural compound, negatively regulates HR but not NHEJ by interfering Rad51 recruitment, resulting in severe cytotoxicity in hepatoma cells. Furthermore, NHEJ inhibitor Nu7441 markedly sensitizes Hep3B cells to the anti-proliferative effects of Harmine. Taken together, our study suggested that Harmine holds great promise as an oncologic drug and combination of Harmine with a NHEJ inhibitor might be an effective strategy for anti-cancer treatment.

No abstract

No abstract

Image steganography is the technique of hiding secret information within images. It is an important research direction in the security field. Benefitting from the rapid development of deep neural networks, many steganographic algorithms based on deep learning have been proposed. However, two problems remain to be solved in which the most existing methods are limited by small image size and information capacity. In this paper, to address these problems, we propose a high capacity image steganographic model named HidingGAN. The proposed model utilizes a new secret information preprocessing method and Inception‐ResNet block to promote better integration of secret information and image features. Meanwhile, we introduce generative adversarial networks and perceptual loss to maintain the same statistical characteristics of cover images and stego images in the high‐dimensional feature space, thereby improving the undetectability. Through these manners, our model reaches higher imperceptibility, security, and capacity. Experiment results show that our HidingGAN achieves the capacity of 4 bits‐per‐pixel (bpp) at 256 × 256 pixels, improving over the previous best result of 0.4 bpp at 32 × 32 pixels.

Smartphones are playing an increasingly important role in personal life and carrying massive private data. Unfortunately, once the smartphones are stolen, all the sensitive information, such as contacts, messages, photos, credit card information and passwords, may fall into the hands of malicious people. In order to protect the private data, remote deletion mechanism is required to allow owners to wipe the sensitive data on the stolen phone remotely. Existing remote deletion techniques rely on the availability of either WiFi for Internet connection or SIM card for cellular network connection; however, these requirements may not be satisfied when the phones are stolen by some sophisticated adversaries. In this paper, we propose a new remote deletion mechanism that allows the phone owner to delete the private data remotely even if the WiFi is disabled and the SIM card is unplugged. The basic idea is to use emergency call mechanisms to establish a communication connection with a service provider to verify the state of the phone and perform remote deletion. We present a case study of our mechanism with the Universal Mobile Telecommunications System (UMTS) network.

No abstract

No abstract

Android Framework is a layer of software that exists in every Android system managing resources of all Android apps. A vulnerability in Android Framework can lead to severe hacks, such as destroying user data and leaking private information. With tens of millions of Android devices unpatched due to Android fragmentation, vulnerabilities in Android Framework certainly attract attackers to exploit them. So far, enormous manual effort is needed to craft such exploits. To our knowledge, no research has been done on automatic generation of exploits that take advantage of Android Framework vulnerabilities. We make a first step towards this goal by applying symbolic execution of Android Framework to finding bugs and generating exploits. Several challenges have been raised by the task. (1) The information of an app flows to Android Framework in multiple intricate steps, making it difficult to identify symbolic inputs. (2) Android Framework has a complex initialization phase, which exacerbates the state space explosion problem. (3) A straightforward design that builds the symbolic executor as a layer inside the Android system will not work well: not only does the implementation have to ensure the compatibility with the Android system, but it needs to be maintained whenever Android gets updated. We present novel ideas and techniques to resolve the challenges, and have built the first system for symbolic execution of Android Framework. It fundamentally changes the state of the art in exploit generation on the Android system, and has been applied to constructing new techniques for finding vulnerabilities.