Glutamine antagonist DRP-104 suppresses tumor growth and enhances response to checkpoint blockade in KEAP1 mutant lung cancer.

Loss-of-function mutations in KEAP1 frequently occur in lung cancer and are associated with poor prognosis and resistance to standard of care treatment, highlighting the need for the development of targeted therapies. We previously showed that KEAP1 mutant tumors consume glutamine to support the metabolic rewiring associated with NRF2-dependent antioxidant production. Here, using preclinical patient-derived xenograft models and antigenic orthotopic lung cancer models, we show that the glutamine antagonist prodrug DRP-104 impairs the growth of KEAP1 mutant tumors. We find that DRP-104 suppresses KEAP1 mutant tumors by inhibiting glutamine-dependent nucleotide synthesis and promoting antitumor T cell responses. Using multimodal single-cell sequencing and ex vivo functional assays, we demonstrate that DRP-104 reverses T cell exhaustion, decreases Tregs, and enhances the function of CD4 and CD8 T cells, culminating in an improved response to anti-PD1 therapy. Our preclinical findings provide compelling evidence that DRP-104, currently in clinical trials, offers a promising therapeutic approach for treating patients with KEAP1 mutant lung cancer.

Glutamine antagonist DRP-104 suppresses tumor growth and enhances response to checkpoint blockade in KEAP1 mutant lung cancer.

Loss-of-function mutations in KEAP1 frequently occur in lung cancer and are associated with resistance to standard of care treatment, highlighting the need for the development of targeted therapies. We have previously shown that KEAP1 mutant tumors have increased glutamine consumption to support the metabolic rewiring associated with NRF2 activation. Here, using patient-derived xenograft models and antigenic orthotopic lung cancer models, we show that the novel glutamine antagonist DRP-104 impairs the growth of KEAP1 mutant tumors. We find that DRP-104 suppresses KEAP1 mutant tumor growth by inhibiting glutamine-dependent nucleotide synthesis and promoting anti-tumor CD4 and CD8 T cell responses. Using multimodal single-cell sequencing and ex vivo functional assays, we discover that DRP-104 reverses T cell exhaustion and enhances the function of CD4 and CD8 T cells culminating in an improved response to anti-PD1 therapy. Our pre-clinical findings provide compelling evidence that DRP-104, currently in phase 1 clinical trials, offers a promising therapeutic approach for treating patients with KEAP1 mutant lung cancer. Furthermore, we demonstrate that by combining DRP-104 with checkpoint inhibition, we can achieve suppression of tumor intrinsic metabolism and augmentation of anti-tumor T cell responses.

Factors related to the absorption rate of benign thyroid nodules after image-guided microwave ablation: a 3-year follow-up.

PURPOSE: To assess the absorption rate and factors related to the development of benign thyroid nodules (BTNs) following image-guided microwave ablation (MWA). MATERIALS AND METHODS: This retrospective study reviewed nodule efficacy in patients who underwent MWA of BTNs between January 2016 and January 2018. The endpoint was a third-year follow-up. Nodules were categorized into those showing complete absorption (volumes with less than 100% volume reduction ratio (VRR) and those showing partial absorption (100% VRR)). Univariable and multivariable regression analyses were carried out to identify variables that were associated with nodule absorption rates. RESULTS: A total of 173 BTNs (median volume= 4.23 ml; 25-75 percentiles= 2.27-9.00 ml) from 173 patients were evaluated. 49.7% (86/173) of patients had nodules that became completely absorbed. The mean VRRs of all BTNs were 18.0%, 78.7%, 89.0%, 94.5%, and 97.1% at the 1-, 6-,12-, 24- and 36- month follow-ups. At the 3-year follow-up time point, nodule characteristics related to nodule VRR included nodule volume (adjusted odds ratio [AOR], 1.1 [95% CI: 1.0, 1.2]; p = 0.03) and nodule margin (AOR, 5.3 [95% CI: 1.8, 16.0]; p < 0.01). Treatment-related characteristics included energy per ml in nodular volume (AOR, 1.0 [95% CI: 1.0, 1.0]; p < 0.01) and blockage of peripheral flow (AOR, 3.3 [95% CI: 1.3 8.3]; p = 0.01). CONCLUSIONS: US-guided image-guided MWA results in satisfactory long-term outcomes for the patients with BTNs. Factors related to nodule absorption rate were the volume and margin of the nodule, energy per ml in nodular volume and blockage of peripheral flow.

Activation of the NRF2 antioxidant program sensitizes tumors to G6PD inhibition.

The KEAP1/NRF2 pathway promotes metabolic rewiring to support redox homeostasis. Activation of NRF2 occurs in many cancers, often due to KEAP1 mutations, and is associated with more aggressive disease and treatment resistance. To identify metabolic dependencies in cancers with NRF2 activation, we performed a metabolism-focused CRISPR screen. Glucose-6-phosphate dehydrogenase (G6PD), which was recently shown to be dispensable in Ras-driven tumors, was a top dependency. G6PD catalyzes the committed step of the oxidative pentose phosphate pathway that produces NADPH and nucleotide precursors, but neither antioxidants nor nucleosides rescued. Instead, G6PD loss triggered tricarboxylic acid (TCA) intermediate depletion because of up-regulation of the alternative NADPH-producing enzymes malic enzyme and isocitrate dehydrogenase. In vivo, G6PD impairment markedly suppressed KEAP1 mutant tumor growth, and this suppression was further augmented by TCA depletion by glutaminase inhibition. Thus, G6PD inhibition­induced TCA depletion is a therapeutic vulnerability of NRF2-activated cancer.

UBQLN4 is an ATM substrate that stabilizes the anti-apoptotic proteins BCL2A1 and BCL2L10 in mesothelioma.

ATM serine/threonine kinase (ATM; previously known as ataxia-telangiectasia mutated) plays a critical role in maintaining genomic stability and regulates multiple downstream pathways, such as DNA repair, cell cycle arrest, and apoptosis. As a serine/threonine kinase, ATM has an array of downstream phosphorylation substrates, including checkpoint effector checkpoint kinase 2 (CHK2). ATM inhibits cell cycle progression by phosphorylating and activating CHK2, which plays an important role in the formation and development of tumors and participates in DNA repair responses after double-stranded DNA breaks. In this study, we used a recently developed mammalian functional genetic screening system to explore a series of ATM substrates and their role in DNA damage to enhance our understanding of the DNA damage response. Ubiquilin 4 (UBQLN4), which belongs to the ubiquilin family characterized by its ubiquitin-like (UBL) and ubiquitin-associated (UBA) domains, was identified as a new substrate for ATM. UBQLN4 is involved in various intracellular processes, such as autophagosome maturation, p21 regulation, and motor axon morphogenesis. However, the biological function of UBQLN4 remains to be elucidated. In this study, we not only identified UBQLN4 as a substrate for ATM, but also found that UBQLN4 interacts with and stabilizes the anti-apoptotic proteins Bcl-2-related protein A1 (BCL2A1) and Bcl-2-like protein 10 (BCL2L10) and prevents mesothelioma cell apoptosis in response to DNA damage. These findings expand our understanding of the role of UBQLN4 in mesothelioma and provide new insights into potential mesothelioma treatments targeting substrates for ATM.

SHANK2 is a frequently amplified oncogene with evolutionarily conserved roles in regulating Hippo signaling.

Dysfunction of the Hippo pathway enables cells to evade contact inhibition and provides advantages for cancerous overgrowth. However, for a significant portion of human cancer, how Hippo signaling is perturbed remains unknown. To answer this question, we performed a genome-wide screening for genes that affect the Hippo pathway in Drosophila and cross-referenced the hit genes with human cancer genome. In our screen, Prosap was identified as a novel regulator of the Hippo pathway that potently affects tissue growth. Interestingly, a mammalian homolog of Prosap, SHANK2, is the most frequently amplified gene on 11q13, a major tumor amplicon in human cancer. Gene amplification profile in this 11q13 amplicon clearly indicates selective pressure for SHANK2 amplification. More importantly, across the human cancer genome, SHANK2 is the most frequently amplified gene that is not located within the Myc amplicon. Further studies in multiple human cell lines confirmed that SHANK2 overexpression causes deregulation of Hippo signaling through competitive binding for a LATS1 activator, and as a potential oncogene, SHANK2 promotes cellular transformation and tumor formation in vivo. In cancer cell lines with deregulated Hippo pathway, depletion of SHANK2 restores Hippo signaling and ceases cellular proliferation. Taken together, these results suggest that SHANK2 is an evolutionarily conserved Hippo pathway regulator, commonly amplified in human cancer and potently promotes cancer. Our study for the first time illustrated oncogenic function of SHANK2, one of the most frequently amplified gene in human cancer. Furthermore, given that in normal adult tissues, SHANK2's expression is largely restricted to the nervous system, SHANK2 may represent an interesting target for anticancer therapy.

BAP1 regulates AMPK-mTOR signalling pathway through deubiquitinating and stabilizing tumour-suppressor LKB1.

Liver kinase B1 (LKB1), a tumour suppressor, participates in many cellular processes, including cell survival, growth, apoptosis, transformation, and metabolism. Upon performing yeast two-hybrid screening, co-immunoprecipitation, and GST pull-down, we identified that BRCA1-associated protein 1 (BAP1), a deubiquitinase, interacts with LKB1. Immunoblotting was performed to examine the effect of BAP1 on the activation of 5' AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR), downstream of LKB1. The relationship between BAP1 deficiency and cancer cell proliferation was examined using cell survival assay and soft agar assay. qRT-PCR and oil red O staining were performed to evaluate lipid synthesis. Our findings reveal that BAP1 deubiquitinates LKB1, inhibits its degradation, and stabilises it, thereby affecting AMPK activation and downstream mTOR activity. BAP1 deficiency may enhance cellular proliferation as well as lipid synthesis.

Defining relative mutational difficulty to understand cancer formation.

Most mutations in human cancer are low-frequency missense mutations, whose functional status remains hard to predict. Here, we show that depending on the type of nucleotide change and the surrounding sequences, the tendency to generate each type of nucleotide mutations varies greatly, even by several hundred folds. Therefore, a cancer-promoting mutation may appear only in a small number of cancer cases, if the underlying nucleotide change is too difficult to generate. We propose a method that integrates both the original mutation counts and their relative mutational difficulty. Using this method, we can accurately predict the functionality of hundreds of low-frequency missense mutations in p53, PTEN, and INK4A. Many loss-of-function p53 mutations with dominant negative effects were identified, and the functional importance of several regions in p53 structure were highlighted by this analysis. Our study not only established relative mutational difficulties for different types of mutations in human cancer, but also showed that by incorporating such a parameter, we can bring new angles to understanding cancer formation.

Can Combined Screening of Ultrasound and Elastography Improve Breast Cancer Identification Compared with MRI in Women with Dense Breasts-a Multicenter Prospective Study.

Objectives: To assess the performance of elastography (ES) and ultrasound (US) in predicting the malignancy of breast lesions and to compare their combined diagnostic value with that of magnetic resonance imaging (MRI). Materials and Methods: The study prospectively enrolled 242 female patients with dense breasts treated in 35 heath care facilities in China between November 2018 and October 2019. Based on conventional US and elastography, radiologists classified the degree of suspicion of breast lesions according to the US Breast Imaging Reporting and Data System (BI-RADS) criteria. The diagnostic value was compared between US BI-RADS and MRI BI-RADS, with pathological results used as the reference standard. Results: The results demonstrated that irregular tumor shape, a nonparallel growth orientation, indistinct margins, angular contours, microcalcifications, color Doppler flow and ES score on US imaging were significantly related to breast cancer in dense breasts (P=0.001; P=0.001; P=0.008; P<0.001; P=0.019; P=0.008; P=0.002, respectively). The sensitivity, specificity, PPV, NPV, accuracy and AUC of US BI-RADS category were 94.7%, 90.7%, 95.8%, 88.0%, 93.4% and 0.93 (95%CI, 0.88-0.97), respectively, while those of MRI BI-RADS category were 98.2%, 57.5%, 84.3%, 83.3%, 86.0% and 0.78 (95%CI, 0.71-0.85), respectively. MRI BI-RADS showed a significantly higher sensitivity than US BI-RADS (98.2% vs 94.7%, P=0.043), whereas US BI-RADS showed significantly higher specificity (90.7% vs 57.5%, P<0.001). US BI-RADS showed better diagnostic efficiency in differentiating nodules in dense breasts than MRI BI-RADS (AUC 0.93 vs 0.78, P<0.001). Conclusion: By combining the use of ES and conventional US, US BI-RADS had better diagnostic efficiency in differentiating nodules in dense breasts than MRI. For the diagnosis of malignant tumors in patients with dense breasts, MRI and US BI-RADS can be used as supplemental diagnostic tools to detect lesions, with US BI-RADS considered the preferred adjunctive resource.

Systematic Analysis of Drug Vulnerabilities Conferred by Tumor Suppressor Loss.

In addition to oncogene inhibition, targeting tumor suppressor deficiency could provide potential venues for precision cancer medicine. However, the full spectrum of drug vulnerability conferred by tumor suppressor loss remains unclear. We systematically analyzed how loss of 59 common tumor suppressors each affected cellular sensitivity to 26 different types of anticancer therapeutics. The experiments were performed in a one-gene, one-drug manner, and through such a large gene-drug iteration study, we were able to generate a drug sensitivity map that describes numerous examples of drug resistance or hypersensitivity conferred by tumor suppressor loss. We further delineated the mechanisms of several gene-drug interactions, showing that loss of tumor suppressors could modify drug sensitivity at various steps of drug action. This systematic drug sensitivity map highlights potential drug vulnerabilities associated with tumor suppressor loss, which may help expand precision cancer medicine on the basis of tumor suppressor status.

Incidence of second-time lateral patellar dislocation is associated with anatomic factors, age and injury patterns of medial patellofemoral ligament in first-time lateral patellar dislocation: a prospective magnetic resonance imaging study with 5-year follow-up.

PURPOSE: To examine the predictors of the second-time lateral patellar dislocation (LPD) in patients after acute first-time LPD in a 5-year follow-up. METHODS: Data were collected prospectively from patients after acute first-time LPD with conservative treatment. Factors included sex, age at the first-time LPD, anatomical variants [trochlear dysplasia, patellar height, tibial tuberosity-trochlear groove (TT-TG) distance], and injury patterns of medial patellofemoral ligament (MPFL) in acute first-time LPD. Logistic regression was carried out to identify the independent risk factors for the incidence of the second-time LPD. RESULTS: The incidence rate of a second-time LPD was 35.5% (59 of 166) in the 5-year follow-up. Univariate analysis revealed significant differences in the incidence rate of the second-time LPD among age at the first-time LPD (P = 0.04), trochlear dysplasia (P = 0.003), patella height (P = 0.017) and the TT-TG distance (P = 0.027). Risk factors for the second-time LPD were age < 18 years at the first-time LPD [odds ratio (OR) 4.088], low-grade trochlear dysplasia (OR 7.214), high-grade trochlear dysplasia (OR 18.945), patella alta (OR 8.416), elevated TT-TG distance (OR 12.742), complete MPFL tear at its isolated femoral-side (OR 6.04) and complete combined MPFL tear (OR 5.851). CONCLUSIONS: Trochlear dysplasia, elevated TT-TG distance, patella alta, age < 18 years at the first-time LPD, complete MPFL tear at its isolated femoral-side and complete combined MPFL tear in the first-time LPD are independently associated with a higher incidence rate of the second-time LPD. LEVEL OF EVIDENCE: III.

Radioprotective effect of lactoferrin in mice exposed to sublethal X-ray irradiation.

The radioprotective effect of lactoferrin (LF) was studied in mice subjected to sublethal X-ray irradiation. The mice were randomly divided into the Control (non-irradiated mice fed a standard diet without LF), IR (irradiated mice fed a standard diet) and IR+LF (irradiated mice fed LF) groups. The mice were fed daily for 7 days prior to irradiation and for 30 continuous days following irradiation. The survival ratio of the mice in the IR+LF group was significantly increased compared with the IR group between days 15 and 30 after irradiation. The body weight of the mice in the IR+LF group was increased compared with the IR group, and the difference was statistically significant. Blood was collected from the mice via the tail vein on days 2, 7, 14, 21 and 30 following irradiation. The laboratory indicators, including leukocyte, erythrocyte and platelet counts recovered more rapidly following irradiation in the IR+LF group compared with the IR group. Treatment of the irradiated mice with LF significantly reduced the DNA damage. In the hepatic tissue the level of superoxide dismutase in the IR+LF group was significantly increased, while malondialdehyde was significantly decreased compared with the IR group. These findings indicate that LF may prevent radiation damage and may have potential as a treatment for patients with cancer who receive radiotherapy.

Ultrasonographic manifestations of a rare granular cell tumor of the accessory breast: A case report.

RATIONALE: The ultrasound manifestations of granular cell tumor (GCT) is a consequence of the histopathological characteristic of the tumor and can be distinguished from breast cancer. PATIENT CONCERNS: A GCT is a rare, benign, hyperplasia-based lesion. Approximately 1% to 2% of GCTs are malignant. About 5% to15% of the cases occur in the breast, and it is relatively rare in the axillary accessory breast. There are no effective preventive measures for GCTs, early detection combined with a thorough and wide complete resection of the tumor remains the best treatment for a favorable outcome. DIAGNOSES: A 45-year-old female patient with an axillary mass of more than 3 months duration was examined through physical examination, color Doppler ultrasound and postoperative pathology. INTERVENTIONS: A provisional diagnosis of left axillary lymph node enlargement was made and necessary investigations were advised. OUTCOMES: A differential diagnosis of accessory breast in the left arm pit, possibly malignant, or a solid mass in the left arm pit secondary to chronic inflammation. Postoperative pathology: GCT of axillary accessory breast, with tumor-free margins. Immunohistochemical staining showed strong S-100 positivity, CD68 positivity, and negative periodic acid-Schiff staining. LESSONS: The ultrasound examination can detect GCT mass in the breast/accessory breast and is not easy to misdiagnosis.

Correlation analysis between injury patterns of medial patellofemoral ligament and vastus medialis obliquus after acute first-time lateral patellar dislocation.

PURPOSE: To evaluate the correlation between injury patterns of the medial patellofemoral ligament (MPFL) and vastus medialis obliquus (VMO) after acute first-time lateral patellar dislocation (LPD) in adults. METHODS: Magnetic resonance imaging (MRI) was prospectively performed in 132 consecutive adults with acute first-time LPD. Images were acquired and evaluated using standardized protocols. Injury patterns of MPFL were grouped by location and severity for analysis of the prevalence of VMO injury. RESULTS: MRI demonstrated VMO injury in 63 (47.7%) patients. Twenty (38.5%) and 43 cases (56.6%) were present in partial and complete MPFL tear subgroups, respectively. Compared with partial MPFL tears, complete tears showed a higher prevalence of VMO injury (P = 0.044). The mean coronal (28.5 mm) and mean sagittal VMO elevations (20.7 mm) were higher in the complete MPFL tear subgroup than in the partial tear subgroup (19.8 mm, P = 0.005; 11.9 mm, P < 0.001). No correlations were identified between the prevalence of VMO injury and location subgroups of MPFL injury (n.s.). Mean VMO elevations were higher in isolated femoral-side (FEM) and combined MPFL tear (COM) subgroups (mean coronal VMO elevation of 29 mm and mean sagittal VMO elevation of 20.8 mm in the FEM subgroup; mean coronal VMO elevation of 29.6 mm and mean sagittal VMO elevation of 23.1 mm in the COM subgroup) than in the isolated patellar-side MPFL tear (PAT) subgroup (P = 0.022, P < 0.001) (mean coronal VMO elevation of 20.7 mm and mean sagittal VMO elevation of 10.6 mm). CONCLUSIONS: Complete MPFL tear predisposes to VMO injury and has a higher elevation of torn VMO after acute first-time LPD in adults. Isolated femoral-side and combined MPFL tears predispose to higher elevation of torn VMO. LEVEL OF EVIDENCE: IV.

Immunological mechanism of low-dose priming radiation resistance in walker-256 tumor model mice.

The aim of the present study was to investigate whether low-dose priming radiation induces antitumor immunity that can be augmented by the modulation of natural killer (NK) cell and cytokine activity using a mouse tumor model. Walker-256 cells were injected into the right flank of male BALB/c mice. At 7 days after inoculation, mice were divided into three groups, including group 1,2,3. In group 1 the mice were without radiation, in group 2 the mice were received 2 Gy radiation only, and in group 3 the mice were radiated with a priming dose of 75 mGy followed by 2 Gy radiation after 24 h. On day 21 following the radiation, the tumors were removed and the tumor index (tumor weight as a percentage of body weight) was calculated. At 1, 7, 14 and 21 days following the 2 Gy radiation, mouse splenocytes were isolated to analyze the NK activity and measure the production of the cytokines interleukin-1ß, interferon-γ and tumor necrosis factor-α by ELISA. Apoptosis was also measured by flow cytometry. The results demonstrated that priming radiation significantly delayed the tumor growth and prolonged the median survival time to 38 days compared with the 31-day survival in the 2 Gy radiation group. The percentage of apoptotic cells was significantly higher in the mice that received 75 mGy + 2 Gy radiation compared with that in the mice that received 2 Gy alone; by contrast, mice that were not irradiated exhibited a relatively low level of apoptosis. The primed mice had a higher level of NK activity as compared with the mice exposed to 2 Gy radiation only or mice that were not irradiated. Furthermore, cytokine expression remained at a higher level in mice receiving priming dose of radiation compared that in the mice receiving only 2 Gy radiation. In conclusion, the results indicated that low-dose priming X-ray radiation may enhance the NK activity and the levels of cytokines, and that the immune response serves an important role in anticancer therapy, including radiotherapy.

Injury patterns of medial patellofemoral ligament after acute lateral patellar dislocation in children: Correlation analysis with anatomical variants and articular cartilage lesion of the patella.

OBJECTIVES: To assess the relationship between injury patterns of medial patellofemoral ligament (MPFL) and anatomical variants and patellar cartilage lesions after acute lateral patellar dislocation (LPD) in children. METHODS: MR images were obtained in 140 children with acute LPD. Images were acquired and evaluated using standardised protocols. RESULTS: Fifty-eight cases of partial MPFL tear and 75 cases of complete MPFL tear were identified. Injuries occurred at an isolated patellar insertion (PAT) in 52 cases, an isolated femoral attachment (FEM) in 42 cases and an isolated mid-substance (MID) in five cases. More than one site of injury was identified in 34 cases. Compared with Wiberg patellar type C, Wiberg patellar type B predisposed to complete MPFL tear (P = 0.042). No correlations were identified between injury patterns of MPFL and trochlear dysplasia, patellar height and tibial tuberosity-trochlear groove distance (P > 0.05). Compared with partial MPFL tear, complete MPFL tear predisposed to Grade-IV and Grade-V patellar chondral lesion (P = 0.02). There were no correlations between incidence of patellar cartilage lesion and injury locational-subgroups of MPFL (P = 0.543). CONCLUSIONS: MPFL is most easily injured at the PAT in children. Wiberg patellar type B predisposes to complete MPFL tear. Complete MPFL tear predisposes to a higher grade of patellar chondral lesion. KEY POINTS: • MPFL is most easily injured at its patellar insertion in children. • Wiberg patellar type B predisposes to complete MPFL tear. • No correlations between injury patterns of MPFL and other three anatomical variants. • Complete MPFL tear predisposes to higher grade patellar chondral lesion. • No correlations between injury locations of MPFL and patellar cartilage lesion.

The Sonographic Features of an Oral Lymphoma.

The gastrointestinal tract is the most commonly involved extranodal site in non-Hodgkin lymphomas (NHL). Oral cavity as primary site constitutes only 2% of all extranodal non-Hodgkin lymphomas. The oral buccal mucosa involvement by lymphoma is very rare. Here, the authors report a case of primary mucosa-associated lymphoid tissue lymphoma of the oral mucosa. The sonographic features of the mass are described in depth.

A DNA/HDAC dual-targeting drug CY190602 with significantly enhanced anticancer potency.

Genotoxic drugs constitute a major treatment modality for human cancers; however, cancer cells' intrinsic DNA repair capability often increases the threshold of lethality and renders these drugs ineffective. The emerging roles of HDACs in DNA repair provide new opportunities for improving traditional genotoxic drugs. Here, we report the development and characterization of CY190602, a novel bendamustine-derived drug with significantly enhanced anticancer potency. We show that CY190602's enhanced potency can be attributed to its newly gained ability to inhibit HDACs. Using this novel DNA/HDAC dual-targeting drug as a tool, we further explored HDAC's role in DNA repair. We found that HDAC activities are essential for the expression of several genes involved in DNA synthesis and repair, including TYMS, Tip60, CBP, EP300, and MSL1. Importantly, CY190602, the first-in-class example of such DNA/HDAC dual-targeting drugs, exhibited significantly enhanced anticancer activity in vitro and in vivo. These findings provide rationales for incorporating HDAC inhibitory moieties into genotoxic drugs, so as to overcome the repair capacity of cancer cells. Systematic development of similar DNA/HDAC dual-targeting drugs may represent a novel opportunity for improving cancer therapy.