Summary
Lung cancer is an extremely heterogeneous disease, and its treatment remains one of the most challenging tasks in medicine. Few existing laboratory lung cancer models can faithfully recapitulate the diversity of the disease and predict therapy response. Here, we establish 12 patient-derived organoids from the most common lung cancer subtype, lung adenocarcinoma (LADC). Extensive gene and histopathology profiling show that the tumor organoids retain the histological architectures, genomic landscapes, and gene expression profiles of their parental tumors. Patient-derived lung cancer organoids are amenable for biomarker identification and high-throughput drug screening
in vitro
. This study should enable the generation of patient-derived lung cancer organoid lines, which can be used to further the understanding of lung cancer pathophysiology and to assess drug response in personalized medicine.
Pyridine carboxamides are a class of medicinal agents with activity that includes the reduction of iron-induced renal damage, the regulation of nicotinamidase activity, and radio- and chemosensitization. Such pharmacological activities, and the prevalence of the carboxamide moiety and the importance of amide rotations in biology, motivate detailed investigation of energetics in these systems. In this study, we report the use of dynamic nuclear magnetic resonance to measure the amide rotational barriers in the pyridine carboxamides picolinamide and nicotinamide. The activation enthalpies and entropies of DeltaH++ = 12.9 +/- 0.3 kcal/mol and DeltaS++ = -7.7 +/- 0.9 cal/mol K for nicotinamide and DeltaH++ = 18.3 +/- 0.4 kcal/mol and DeltaS++ = +1.3 +/- 1.0 cal/mol K for picolinamide report a substantial energetic difference for these regioisomers. Ab initio calculations of the rotational barriers are in good agreement with the experimentally determined values and help partition the 5.4 kcal/mol enthalpy difference into its major contributions. Of principal importance are the variations in steric interactions in the ground states of picolinamide and nicotinamide, superior pi electron donation from the pyridine ring in the transition state of nicotinamide, and an intramolecular hydrogen bond in the ground state of picolinamide.
Based on recent advances in organoid research as well as the need to find more accurate models for drug screening in cancer research, patient-derived organoids have emerged as an effective in vitro model system to study cancer. Showing numerous advantages over 2D cell lines, 3D cell lines, and primary cell culture, organoids have been applied in drug screening to demonstrate the correlation between genetic mutations and sensitivity to targeted therapy. Organoids have also been used in co-clinical trials to compare drug responses in organoids to clinical responses in the corresponding patients. Numerous studies have reported the successful use of organoids to predict therapy response in cancer patients. Recently, organoids have been adopted to predict treatment response to radiotherapy and immunotherapy. The development of high throughput drug screening and organoids-on-a-chip technology can advance the use of patient-derived organoids in clinical practice and facilitate therapeutic decision-making.
The development of genetic engineering, especially synthetic biology, greatly contributes to the development of novel metal biosensors. The cad operon encoding cadmium resistance was previously characterized from Pseudomonas putida. In this study, single-, dual-, and triple-signal output Cd(II) biosensors were successfully developed using artificial translationally coupled cad operons. Sensitivity, selectivity, and response toward Cd(II) and Hg(II), of three biosensors were all determined. Reporter signals of three biosensors all increased within the range 0.1–3.125 μM Cd(II). Three biosensors responded strongly to Cd(II), and weakly to Hg(II). However, the detection ranges of Cd(II) and Hg(II) do not overlap in all three biosensors. Next, novel Cd(II) biosensing coupled with bioadsorptive artificial cad operons were assembled for the first time. Cd(II)-induced fluorescence emission, enzymatic indication, and Cd(II) binding protein surface display can be achieved simultaneously. This study provides an example of one way to realize multiple signal outputs and bioadsorption based on the redesigned heavy metal resistance operons, which may be a potential strategy for biodetection and removal of toxic metal in the environment, facilitating the study of the mechanism and dynamics of bioremediation.
A recent hypothesis suggests that tumor-specific killing by radiation and chemotherapy agents is due to defects or loss of cell cycle checkpoints. An important component of some checkpoints is p53-dependent induction of p21cip-1/waf-1. Both p53 and p21 have been shown to be required for microtubule damage checkpoints in mitosis and in G1 phase of the cell cycle and they thus help to maintain genetic stability. We present here evidence that p21cip-1/waf-1 deficiency relaxes the G1 phase microtubule checkpoint that is activated by microtubule damage induced with nocodazole. Reduced p21cip-1/waf-1expression also results in gross nuclear abnormalities and centriole overduplication. p53 has already been implicated in centrosome regulation. Our findings further suggest that the p53/p21 axis is involved in a checkpoint pathway that links the centriole/centrosome cycle and microtubule organization to the DNA replication cycle and thus helps to maintain genomic integrity. The inability to efficiently upregulate p21cip-1/waf-1 in p21cip-1/waf-1antisense-expressing cells in response to microtubule damage could uncouple the centrosome cycle from the DNA cycle and lead to nuclear abnormalicies and polyploidy. A centrosome duplication checkpoint could be a new target for novel chemotherapy strategies.
The
treatment of bladder cancer has recently shown minimal progress.
Gene therapy mediated by CRISPR provides a new option for bladder
cancer treatment. In this study, we developed a versatile liposome
system to deliver the CRISPR-Cas13a gene circuits into bladder cancer
cells. After in vitro studies and intravesical perfusion
studies in mice, this system showed five advantages: (1) CRISPR-Cas13a,
a transcriptional targeting and cleavage tool for gene expression
editing, did not affect the stability of the cell genome; (2) the
prepared liposome systems were targeted to hVEGFR2, which is always
highly expressed in bladder cancer cells; (3) the CRISPR-Cas13a sequence
was driven by an artificial tumor specific promoter to achieve further
targeting; (4) a near-infrared photosensitizer released using near-infrared
light was introduced to control the delivery system; and (5) the plasmids
were constructed with three crRNA tandem sequences to achieve multiple
targeting and wider therapeutic results. This tumor cell targeting
lipid delivery system with near-infrared laser-controlled ability
provided a versatile strategy for CRISPR-Cas13a based gene therapy
of bladder cancer.
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