Triple-negative breast cancer (TNBC) lacks three important receptors, ER, PR, and HER2. It is more aggressive and more likely to relapse after treatment, thus has been identified as one of the most malignant breast cancer types. The development of efficient targeted TNBC therapy is an important research topic in TNBC treatment. We report the development of a new aptamer–drug conjugate (ApDC), AS1411–triptolide conjugate (ATC), as targeted therapy for the treatment of TNBC with high efficacy. The conjugate possesses excellent specificity and high cytotoxicity against the MDA-MB-231 cell line. The advantages of our newly invented ATC are further highlighted by its excellent in vivo anti-TNBC efficacy and negligible side effects toward healthy organs.

Because altered microRNAs (miRNAs) expression patterns have been observed in a variety of diseased tissues, miRNA expression was compared in human cervical cancer tissues relative to adjacent normal cervical tissues in the present study. Microarray chips with 924 probes were used to detect the expression of miRNAs in cervical cancer tissue and adjacent normal cervical tissue of 13 patients with cervical cancer (11 squamous cervical cancers, one cervical adenocarcinoma, and one cervical sarcoma), all of whom were infected with human papilloma virus (HPV) 16 and/or HPV18. Compared to the expression levels in normal cervical tissues, 18 miRNAs (1.9%) were significantly upregulated (increase of ≥2×), and 19 miRNAs (2.1%) were significantly downregulated (decrease of ≤0.5×) in cervical cancer tissues. miRNA expression was independent of lymph node involvement, vascular invasion, and pathological differentiation. Taken together, cervical cancer tissues have altered expression of miRNAs relative to adjacent normal tissues. Further studies are necessary to determine whether aberrant miRNA expression is related to the pathogenesis of cervical cancer.

Aptamers and antibodies, as molecular recognition probes, play critical roles in cancer diagnosis and therapy. However, their recognition ability is based on target overexpression in disease cells, not target exclusivity, which can cause on-target off-tumor effects. To address the limitation, we herein report a novel strategy to develop a conditional aptamer conjugate which recognizes its cell surface target, but only after selective activation, as determined by characteristics of the disease microenvironment, which, in our model, involve tumor hypoxia. This conditional aptamer is the result of conjugating the aptamer with PEG5000-azobenzene-NHS, which is responsive to hypoxia, here acting as a caging moiety of conditional recognition. More specifically, the caging moiety is unresponsive in the intact conjugate and prevents target recognition. However, in the presence of sodium dithionite or hypoxia (<0.1% O2) or in the tumor microenvironment, the caging moiety responds by allowing conditional recognition of the cell-surface target, thereby reducing the chance of on-target off-tumor effects. It is also confirmed that the strategy can be used for developing a conditional antibody. Therefore, this study demonstrates an efficient strategy by which to develop aptamer/antibody-based diagnostic probes and therapeutic drugs for cancers with a unique hypoxic microenvironment.

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Polytherapy( or drug combination cancer therapy (DCCT)), targeting multiple mechanisms associated with tumor proliferation, can efficiently maximizet herapeutic efficacy,d ecrease drug dosage,a nd reduce drug resistance. However,most DCCT strategies cannot coordinate the specific delivery of adrug combination in an accurately tuned ratio into cancer cells.T oa ddress these limitations,t he present work reports the engineering of circular bivalent aptamer-drug conjugates (cb-ApDCs). The cb-ApDCs exhibit high stability, specific recognition, excellent cellular uptake,a nd esterasetriggered release.F urthermore,t he drug ratios in cb-ApDCs can be tuned for an enhanced synergistic effect without the need for complex chemistry.T herefore,c b-ApDCs provide apromising platform for the development of DCCT strategies for different drug combinations and ratios.

Arsenic trioxide (ATO, As2O3) is currently used to treat acute promyelocytic leukemia. However, expanding its use to include high-dose treatment of other cancers is severely hampered by serious side effects on healthy organs. To address these limitations, we loaded ATO onto folate (FA)-labeled human serum albumin (HSA) pretreated with glutathione (GSH) based on the low pH- and GSH-sensitive arsenic-sulfur bond, and we termed the resulting smart nanodrug as FA-HSA-ATO. FA-HSA-ATO could specifically recognize folate receptor-β-positive (FRβ+) chronic myeloid leukemia (CML) cells, resulting in more intracellular accumulation of ATO. Furthermore, the nanodrug could upregulate FRβ expression in CML cancer cells and xenograft tumor model, facilitating even more recruitment and uptake of FRβ-targeting drugs. In vitro and in vivo experiments indicate that the nanodrug significantly alleviates side effects and improves therapeutic efficacy of ATO on CML and xenograft tumor model.

Pharmacokinetic drug–drug interactions (DDIs) occur when a drug alters the absorption, transport, distribution, metabolism or excretion of a co-administered agent. The occurrence of pharmacokinetic DDIs may result in the increase or the decrease of drug concentrations, which can significantly affect the drug efficacy and safety in patients. Enzyme-mediated DDIs are of primary concern, while the transporter-mediated DDIs are less understood but also important. In this review, we presented an overview of the different mechanisms leading to DDIs, the in vitro experimental tools for capturing the factors affecting DDIs, and in silico methods for quantitative predictions of DDIs. We also emphasized the power and strategy of physiologically based pharmacokinetic (PBPK) models for the assessment of DDIs, which can integrate relevant in vitro data to simulate potential drug interaction in vivo. Lastly, we pointed out the future directions and challenges for the evaluation of pharmacokinetic DDIs.

Purpose The role of HHLA2, a new immune checkpoint ligand, is gradually being elucidated in various solid tumours. However, its role in ovarian cancer remains unclear; thus, its expression profile and clinical significance in ovarian cancer must be examined. Methods We performed immunohistochemistry to examine HHLA2 expression in 64 ovarian cancer tissues and 16 normal ovarian tissues. The relationships between HHLA2 expression and clinicopathological features, prognosis, and CD8+ tumour-infiltrating lymphocytes (TILs) in patients were analysed. Additionally, the Cancer Cell Line Encyclopedia database was used to analyse the correlation between HHLA2 expression and PD-L1 or B7x expression. Furthermore, the biological function of HHLA2 in ovarian cancer cells was initially explored. Results Only 17.2% of ovarian cancer patients showed HHLA2 expression, which was significantly associated with the differentiation of ovarian cancer cells (p = 0.027), and well-differentiated tumours expressed higher levels of HHLA2. The density of CD8+ TIL was associated with increased HHLA2 expression (p = 0.017), and the CD8+ TIL count was higher in the HHLA2-positive group than that in the HHLA2-negative group (p = 0.023). Moreover, multivariate analysis identified HHLA2 expression as an independent prognostic factor that predicted improved survival (p = 0.049; HR = 0.156; 95% CI = 0.025–0.992). Additionally, we also found that overexpressing HHLA2 inhibited the proliferation of ovarian cancer cells. Conclusion HHLA2 is associated with tumour differentiation and high CD8+ TIL levels; and predicts improved survival in ovarian cancer. Along with previously reported findings that HHLA2 behaves as a co-stimulatory ligand, our study suggests that the loss of HHLA2 may contribute to the immunosuppressive microenvironment and progression of ovarian cancer.