Correction: A preliminary study for the development of cleavable linkers using activatable fluorescent probes targeting leucine aminopeptidase.

Correction for 'A preliminary study for the development of cleavable linkers using activatable fluorescent probes targeting leucine aminopeptidase' by Julie Kang et al., Analyst, 2022, https://doi.org/10.1039/d2an01145j.

A preliminary study for the development of cleavable linkers using activatable fluorescent probes targeting leucine aminopeptidase.

Ligand-targeted drugs (LTDs) such as antibody-drug conjugates (ADCs) are currently attracting great attention as an alternative class of therapeutics to conventional chemotherapy for the clinical treatment of cancer. The linker is one of important factors determining the efficacy and toxicity of LTDs. The linker for LTDs should have enough stability during blood circulation, effectively release the payload, and leave no polar moieties in the released payload. However, the drug release activity and plasma stability of cleavable linkers are generally evaluated by complex and sophisticated in vivo techniques containing LC-MS, and the designing of new clinically applicable linkers remains a challenge. In this work, leucine aminopeptidase (LAP)-responsive fluorescent probes were designed as a simple preliminary model to verify whether a peptidase-responsive fluorescent probe can be used as a facile tool for the development of cleavable linkers although LAP is an exopeptidase and can't be a real target for cleavable linkers. LAP-responsive fluorescent probes were prepared by conjugation of a leucine to several xanthene fluorophores through a few linkages with a p-aminobenzyl spacer. The stability tests, kinetic study and live cell imaging of LAP-responsive activatable fluorescent probes demonstrated that the chemical stability and intrinsic activity of the linker for the release of drug can be easily evaluated by a fluorogenic assay. The ex vivo plasma stability test using mice suggested that an enzyme-responsive activatable fluorescent probe can be used as a feasible platform to evaluate the plasma stability of cleavable linkers during blood circulation.

Photoelectron spectroscopy of cryogenically cooled NiO2-via slow photoelectron velocity-map imaging.

High-resolution anion photoelectron spectra of cryogenically cooled NiO2- anions, obtained using slow photoelectron velocity-map imaging (cryo-SEVI), are presented in tandem with coupled cluster electronic structure calculations including relativistic effects. The experimental spectra encompass the X̃1Σg+ ← X̃2Πg, ã3Πg ← X̃2Πg, and Ã1Πg ← X̃2Πg photodetachment transitions of linear ONiO0/-, revealing previously unobserved vibrational structure in all three electronic bands. The high-resolution afforded by cryo-SEVI allows for the extraction of vibrational frequencies for each state, consistent with those previously measured in the ground state and in good agreement with scalar-relativistic coupled-cluster calculations. Previously unobserved vibrational structure is observed in the ã3Πg and Ã1Πg states and is tentatively assigned. Further, a refined electron affinity of 3.0464(7) eV for NiO2 is obtained as well as precise term energies for the ã and à states of NiO2 of 0.3982(7) and 0.7422(10) eV, respectively. Numerous Franck-Condon forbidden transitions involving the doubly degenerate ν2 bending mode are observed and ascribed to Herzberg-Teller coupling to an excited electronic state.

Psychological Impact of Type of Breast Cancer Surgery: A National Cohort Study.

BACKGROUND: The present study assessed the impact of different types of breast surgery on rates of psychological disorders in breast cancer patients. METHODS: This nationwide cohort study, based on Korean Health Insurance Review and Assessment Service claims data, included 26,259 breast patients who underwent surgery from June 1, 2017, to December 31, 2018. Associations between the incidence of psychological disorders and variables were evaluated by time dependent Cox regression analyses. RESULTS: Of the 26,259 patients, 9394 (35.8%) underwent total mastectomy (TM) and 16,865 (64.2%) underwent partial mastectomy (PM); of the former, 4056 (43.2%) underwent breast reconstruction surgery (RS). A total of 4685 patients (17.84%) were newly diagnosed with psychological disorders after surgery. Multivariable analysis showed that axillary lymph node dissection was significantly associated with increased rates of overall psychological disorders (p < 0.0001), depression (p = 0.0462), anxiety (p < 0.0001) and insomnia (p < 0.0001). The rates of overall psychological disorders (p = 0.0002) and insomnia (p = 0.01) were significantly lower in patients who underwent TM than PM. RS tended to associated with reduced rates of overall psychological disorders in patients who underwent TM. Subgroup analysis showed that, compared with PM, RS after TM significantly associated with a reduced incidence of overall psychological disorders and insomnia in younger patients (< 50 years) and those who underwent sentinel lymph node biopsy. CONCLUSION: In contrast to general belief, rates of overall psychological disorders and insomnia were lower in patients who underwent TM than PM. Moreover, RS after TM confers psychological benefit in younger patients with early stage breast cancer compared with PM.

Maturation of human intestinal organoids in vitro facilitates colonization by commensal lactobacilli by reinforcing the mucus layer.

Lactobacilli, which are probiotic commensal bacteria that mainly reside in the human small intestine, have attracted attention for their ability to exert health-promoting effects and beneficially modulate host immunity. However, host epithelial-commensal bacterial interactions are still largely unexplored because of limited access to human small intestinal tissues. Recently, we described an in vitro maturation technique for generating adult-like, mature human intestinal organoids (hIOs) from human pluripotent stem cells (hPSCs) that closely resemble the in vivo tissue structure and cellular diversity. Here, we established an in vitro human model to study the response to colonization by commensal bacteria using luminal microinjection into mature hIOs, allowing for the direct examination of epithelial-bacterial interactions. Lactobacillus reuteri and Lactobacillus plantarum were more likely to survive and colonize when microinjected into the lumen of mature hIOs than when injected into immature hIOs, as determined by scanning electron microscopy, colony formation assay, immunofluorescence, and real-time imaging with L plantarum expressing red fluorescent protein. The improved mature hIO-based host epithelium system resulted from enhanced intestinal epithelial integrity via upregulation of mucus secretion and tight junction proteins. Our study indicates that mature hIOs are a physiologically relevant in vitro model system for studying commensal microorganisms.

Multigene Panel Testing for Hereditary Cancer and Genetic Counseling.

As sequencing technology and information of the genomic causes for cancer development expand, multi-gene panel testing for hereditary cancer is increasing in clinical practice. In this chapter, we reviewed the application of multi-gene panel with pre-/post- testing considerations and summarized genetic counseling based on panel testing results in clinical field. In addition, we introduce multi-gene panel for hereditary cancer developed in Seoul National University Hospital.

Multimodal Imaging Probe Development for Pancreatic ß Cells: From Fluorescence to PET.

Pancreatic ß cells are responsible for insulin secretion and are important for glucose regulation in a healthy body and diabetic disease patient without prelabeling of islets. While the conventional biomarkers for diabetes have been glucose and insulin concentrations in the blood, the direct determination of the pancreatic ß cell mass would provide critical information for the disease status and progression. By combining fluorination and diversity-oriented fluorescence library strategy, we have developed a multimodal pancreatic ß cell probe PiF for both fluorescence and for PET (positron emission tomography). By simple tail vein injection, PiF stains pancreatic ß cells specifically and allows intraoperative fluorescent imaging of pancreatic islets. PiF-injected pancreatic tissue even facilitated an antibody-free islet analysis within 2 h, dramatically accelerating the day-long histological procedure without any fixing and dehydration step. Not only islets in the pancreas but also the low background of PiF in the liver allowed us to monitor the intraportal transplanted islets, which is the first in vivo visualization of transplanted human islets without a prelabeling of the islets. Finally, we could replace the built-in fluorine atom in PiF with radioactive 18F and successfully demonstrate in situ PET imaging for pancreatic islets.

Long-term prognostic effect of hormone receptor subtype on breast cancer.

PURPOSE: To determine the long-term prognostic role of hormone receptor subtype in breast cancer using surveillance, epidemiology, and end results (SEER) database. METHODS: Data of 810,587 female operable invasive breast cancer patients from SEER database with a mean follow-up period of 94.2 months (range, 0-311 months) were analyzed. Hormone receptor subtype was classified into four groups based on estrogen receptor (ER) and progesterone receptor (PR) statuses: ER(+)/PR(+), ER(+)/PR(-), ER(-)/PR(+), and ER(-)/PR(-). RESULTS: Numbers of subjects with ER(+)/PR(+), ER(+)/PR(-), ER(-)/PR(+), ER(-)/PR(-), and unknown were 496,279 (61.2%), 86,858 (10.7%), 11,545 (1.4%), 135,441 (16.7%), and 80,464 (9.9%), respectively. The ER(+)/PR(+) subtype showed the best breast-cancer-specific survival, followed by ER(+)/PR(-), ER(-)/PR(+), and ER(-)/PR(-) subtypes in the respective order (all p < 0.001). Survival difference among hormone receptor subtypes was maintained in subgroup analysis according to anatomic stage, race, age group, and year of diagnosis. Hormone receptor subtype was a significant independent prognostic factor in multivariable analyses (p < 0.001). Hazard ratios of ER(+)/PR(-), ER(-)/PR(+), and ER(-)/PR(-) for breast-cancer-specific mortality risk were 1.419 (95% confidence interval [CI] 1.383-1.456), 1.630 (95% CI 1.537-1.729), and 1.811 (95% CI 1.773-1.848), respectively, with ER(+)/PR(+) as reference. CONCLUSION: Hormone receptor subtype is a significant independent prognostic factor in female operable invasive breast cancer patients with long-term effect. The ER(+)/PR(+) subtype shows the most favorable prognosis, followed by ER(+)/PR(-), ER(-)/PR(+), and ER(-)/PR(-) subtypes in the respective order. Prognostic impacts of hormone receptor subtypes are also maintained in subgroup analysis according to anatomic stage, race, age, and year of diagnosis.

Holding-Oriented versus Gating-Oriented Live-Cell Distinction: Highlighting the Role of Transporters in Cell Imaging Probe Development.

Small molecule imaging probes are powerful tools to understand complex biological systems. The mainstreams of imaging probe developments have been focused on the target holding of the probes; the holding targets are often cell-type-specific biomarkers. This type of the probe mechanism can be designated as holding-oriented live-cell distinction (HOLD). Our group has worked on the development of cell-type-selective probes using a diversity-oriented fluorescence library approach (DOFLA), where unbiased phenotypic screening is employed using fluorescent library compounds. Through the conventional target identification methods such as an affinity-based analysis, we elucidated that some of the probe mechanisms are HOLD. However, we also realized that sometimes there is no specific holding target for probes or the holding targets are ubiquitous. The observation led us to test an alternative mechanism of cell-type-specific probes as gating-oriented live-cell distinction (GOLD). We started to examine the gating mechanism of probes, which is mainly based on transporters but which does not necessarily require probe holding to cellular targets. Transporters can control the in and out movement of various nutrients and chemicals. Different expression levels of transporters in various cell types could provide the molecular mechanism of differential staining of cells by regulating the intracellular accumulation of a certain specific probe. A number of GOLD probes have been developed by modifying or mimicking endogenous substrates of transporters such as inorganic ions, glucose, amino acids, or neurotransmitters, utilizing broad substrate specificity of transporters. The radiolabeled or fluorophore-conjugated substrate mimetics have been widely used for live cell distinction and various applications such as disease-related cell or tissue imaging. In humans, there are about 400 solute carrier (SLC) transporters and 50 ATP-binding cassette (ABC) transporters. Since some transporters have broad substrate specificity, they can transport not only derivatives of endogenous natural substrates but also totally synthetic diverse imaging probes, such as DOFLA probes. Without preconsidering the structure of endogenous substrates, we recently demonstrated a series of live-cell imaging probes and elucidated their molecular mechanism as a gating one, either by SLC or ABC transporters. Transporter inhibitor panel and CRISPR-based transporter libraries could provide a systematic gating target elucidation platform. Considering the generality of DOFLA and the CRISPR-based genomic tool for transporter systems (>450 in humans), the GOLD approach will offer new insight and promise for unprecedented levels of novel cell imaging probe development.

A Near-Infrared Probe Tracks and Treats Lung Tumor Initiating Cells by Targeting HMOX2.

Tumor initiating cells (TIC) are resistant to conventional anticancer therapy and associated with metastasis and relapse in cancer. Although various TIC markers and their antibodies have been proposed, it is limited to the use of antibodies for in vivo imaging or treatment of TIC. In this study, we discovered heme oxygenase 2 (HMOX2) as a novel biomarker for TIC and developed a selective small molecule probe TiNIR (tumor initiating cell probe with near infrared). TiNIR detects and enriches the functionally active TIC in human lung tumors, and through the photoacoustic property, TiNIR also visualizes lung TIC in the patient-derived xenograft (PDX) model. Furthermore, we demonstrate that TiNIR inhibits tumor growth by blocking the function of HMOX2, resulting in significantly increased survival rates of the cancer model mice. The novel therapeutic target HMOX2 and its fluorescent ligand TiNIR will open a new path for the molecular level of lung TIC diagnosis and treatment.

High-Pressure Melt Curve and Phase Diagram of Lithium.

We investigate the phase diagram of lithium at temperatures of 200 to 400 K, to pressures over 100 GPa using x-ray diffraction in diamond anvil cells, covering the region in which the melting curve is disputed. To overcome degradation of the diamond anvils by dense lithium we utilize a rapid compression scheme taking advantage of the high flux available at modern synchrotrons. Our results show the hR1 and cI16 phases to be stable to higher temperature than previously reported. The melting minima of lithium is found to be close to room temperature between 40 and 60 GPa, below which the solid is crystalline. Analysis of the stability fields of the cI16 and oC88 phases suggest the existence of a triple point between these and an undetermined solid phase at 60 GPa between 220 and 255 K.

Isomer-specific vibronic structure of the 9-, 1-, and 2-anthracenyl radicals via slow photoelectron velocity-map imaging.

Polycyclic aromatic hydrocarbons, in various charge and protonation states, are key compounds relevant to combustion chemistry and astrochemistry. Here, we probe the vibrational and electronic spectroscopy of gas-phase 9-, 1-, and 2-anthracenyl radicals (C14H9) by photodetachment of the corresponding cryogenically cooled anions via slow photoelectron velocity-map imaging (cryo-SEVI). The use of a newly designed velocity-map imaging lens in combination with ion cooling yields photoelectron spectra with <2 cm(-1) resolution. Isomer selection of the anions is achieved using gas-phase synthesis techniques, resulting in observation and interpretation of detailed vibronic structure of the ground and lowest excited states for the three anthracenyl radical isomers. The ground-state bands yield electron affinities and vibrational frequencies for several Franck-Condon active modes of the 9-, 1-, and 2-anthracenyl radicals; term energies of the first excited states of these species are also measured. Spectra are interpreted through comparison with ab initio quantum chemistry calculations, Franck-Condon simulations, and calculations of threshold photodetachment cross sections and anisotropies. Experimental measures of the subtle differences in energetics and relative stabilities of these radical isomers are of interest from the perspective of fundamental physical organic chemistry and aid in understanding their behavior and reactivity in interstellar and combustion environments. Additionally, spectroscopic characterization of these species in the laboratory is essential for their potential identification in astrochemical data.

Breast Sparganosis Presenting with a Painless Breast Lump: Report of Two Cases.

Sparganosis is a parasitic infestation caused by sparganum, a plerocercoid tapeworm larva of the genus Spirometra. Since the first case of human sparganosis reported in 1908, sparganosis has been a global disease, and is common in China, Japan, and Southeast Asian countries. Consumption of raw snakes, frogs, fish, or drinking contaminated beverages are sources of human infections. Human sparganosis usually manifests in subcutaneous fat in areas such as the abdomen, genitourinary tract, and limbs. Breast sparganosis cases are rare, representing less than 2% of total cases of human infections. Complete surgical extraction of the sparganum is the treatment of choice. Because of the rarity of the disease, clinical suspicion is vital to reach the diagnosis of breast sparganosis. Here we report 2 rare cases of breast sparganosis presenting with a painless breast lump, both treated with surgical excision and sparganum extraction.

Development of a Universal Fluorescent Probe for Gram-Positive Bacteria.

The rapid and sensitive classification of bacteria is the first step of bacterial community research and the treatment of infection. Herein, a fluorescent probe BacGO is presented, which shows the best universal selectivity for Gram-positive bacteria among known probes with a minimum staining procedure for sample detection and enrichment of the live bacteria. BacGO could also be used to assess of the Gram status in the bacterial community from wastewater sludge. Furthermore, BacGO could sensitively and selectively detect a Gram-positive bacterial infection, not only in vitro but also using an in vivo keratitis mouse model. BacGO provides an unprecedented research tool for the study of dynamic bacterial communities and for clinical application.

Tamoxifen therapy improves overall survival in luminal A subtype of ductal carcinoma in situ: a study based on nationwide Korean Breast Cancer Registry database.

PURPOSE: To determine the prognostic role of tamoxifen therapy for patients with ductal carcinoma in situ (DCIS) according to molecular subtypes. METHODS: Data of 14,944 patients with DCIS were analyzed. Molecular subtypes were classified into four categories based on expression of estrogen receptor (ER)/progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2). Kaplan-Meier estimator was used for overall survival analysis while Cox proportional hazards model was used for univariate and multivariate analyses. RESULTS: Luminal A subtype (ER/PR+, HER2-) showed higher (P = .009) survival rate than triple-negative (TN) subtype. Tamoxifen therapy group showed superior (P < .001) survival than no-tamoxifen therapy group. It had survival benefit only for luminal A subtype (P = .001). Tamoxifen therapy resulted in higher survival rate in subgroups with positive ER (P = .006), positive PR (P = .009), and negative HER2 (P < .001). In luminal A subtype, tamoxifen therapy showed lower hazard ratio (HR) compared to no-tamoxifen therapy (HR, 0.420; 95% CI 0.250-0.705; P = .001). Tamoxifen therapy was a significant independent factor by multivariate analysis (HR, 0.538; 95% CI 0.306-0.946; P = .031) as well as univariate analysis. CONCLUSION: Tamoxifen therapy group showed superior prognosis than the no-tamoxifen therapy group. Its prognostic influence was only effective for luminal A subtype. Patients with luminal A subtype showed higher survival rate than those with TN subtype. Active tamoxifen therapy is recommended for DCIS patients with luminal A subtype, and routine tests for ER, PR, and HER2 should be considered for DCIS.

Identification of Tumor Initiating Cells with a Small-Molecule Fluorescent Probe by Using Vimentin as a Biomarker.

Tumor initiating cells (TICs) have been implicated in clinical relapse and metastasis of a variety of epithelial cancers, including lung cancer. While efforts toward the development of specific probes for TIC detection and targeting are ongoing, a universal TIC probe has yet to be developed. We report the first TIC-specific fluorescent chemical probe, TiY, with identification of the molecular target as vimentin, a marker for epithelial-to-mesenchymal transition (EMT). TiY selectively stains TICs over differentiated tumor cells or normal cells, and facilitates the visualization and enrichment of functionally active TICs from patient tumors. At high concentration, TiY also shows anti-TIC activity with low toxicity to non-TICs. With the unexplored target vimentin, TiY shows potential as a first universal probe for TIC detection in different cancers.

Two-Photon Dye Cocktail for Dual-Color 3D Imaging of Pancreatic Beta and Alpha Cells in Live Islets.

Insulin-secreting beta cells together with glucagon-producing alpha cells play an essential role in maintaining the optimal blood glucose level in the body, so the development of selective probes for imaging of these cell types in live islets is highly desired. Herein we report the development of a 2-glucosamine-based two-photon fluorescent probe, TP-ß, that is suitable for imaging of beta cells in live pancreatic islets from mice. Flow cytometry studies confirmed that TP-ß is suitable for isolation of primary beta cells. Moreover, two-photon imaging of TP-ß-stained pancreatic islets showed brightly stained beta cells in live islets. Insulin enzyme-linked immunosorbent assays revealed that TP-ß has no effect on glucose-stimulated insulin secretion from the stained islet. Finally, to develop a more convenient islet imaging application, we combined our recently published alpha-cell-selective probe TP-α with TP-ß to make a "TP islet cocktail". This unique dye cocktail enabled single excitation (820 nm) and simultaneous dual-color imaging of alpha cells (green) and beta cells (red) in live pancreatic islets. This robust TP islet cocktail may serve as a valuable tool for basic diabetic studies.

The influences of peritumoral lymphatic invasion and vascular invasion on the survival and recurrence according to the molecular subtypes of breast cancer.

PURPOSE: We aimed to compare the influences of lymphatic invasion (LI) and vascular invasion (VI) on survival and recurrence according to the molecular subtypes of breast cancer. METHODS: We retrospectively analyzed data on 820 breast cancer patients and assessed overall survival (OS) and disease-free survival (DFS) according to LI and VI using the Kaplan-Meier estimator and the Cox proportional hazards model. RESULTS: Both positive LI and positive VI showed inferior OS and DFS compared with negative LI and negative VI (all p < 0.001). Both positive LI and positive VI showed higher local, regional, and distant recurrence rates (p = 0.002 for regional recurrence of VI, p < 0.001 for all the others). Although LI was a significant independent predictor of OS (hazard ratio [HR] 1.927; 95% confidence interval [CI] 1.046-3.553) and DFS (HR 1.815; 95% CI 1.063-3.096), VI was not in the multivariate analyses. Regarding OS, both positive LI and positive VI showed worse survival rates in the luminal A (p = 0.016 and p = 0.024, respectively) and triple negative subtypes (both p < 0.001). Regarding DFS, LI was a significant prognosticator in the luminal A and triple negative (both p < 0.001) subtypes. VI was a significant prognosticator across all molecular subtypes, although the prognostic impact was most prominent in the luminal A subtype (p < 0.001). CONCLUSIONS: Both LI and VI were significant, unfavorable prognostic factors of OS and DFS, especially in the luminal A and triple negative breast cancer subtypes. Although LI was a significant independent predictor of OS and DFS, VI was not after the multivariate analyses.

Low-lying vibronic level structure of the ground state of the methoxy radical: Slow electron velocity-map imaging (SEVI) spectra and Köppel-Domcke-Cederbaum (KDC) vibronic Hamiltonian calculations.

A joint experimental and theoretical study is reported on the low-lying vibronic level structure of the ground state of the methoxy radical using slow photoelectron velocity-map imaging spectroscopy of cryogenically cooled, mass-selected anions (cryo-SEVI) and Köppel-Domcke-Cederbaum (KDC) vibronic Hamiltonian calculations. The KDC vibronic model Hamiltonian in the present study was parametrized using high-level quantum chemistry, allowing the assignment of the cryo-SEVI spectra for vibronic levels of CH3O up to 2000 cm-1 and of CD3O up to 1500 cm-1 above the vibrational origin, using calculated vibronic wave functions. The adiabatic electron affinities of CH3O and CD3O are determined from the cryo-SEVI spectra to be 1.5689 ± 0.0007 eV and 1.5548 ± 0.0007 eV, respectively, demonstrating improved precision compared to previous work. Experimental peak splittings of <10 cm-1 are resolved between the e1/2 and e3/2 components of the 61 and 51 vibronic levels. A pair of spin-vibronic levels at 1638 and 1677 cm-1 were predicted in the calculation as the e1/2 and e3/2 components of 62 levels and experimentally resolved for the first time. The strong variation of the spin-orbit splittings with a vibrational quantum number is in excellent agreement between theory and experiment. The observation of signals from nominally forbidden a1 vibronic levels in the cryo-SEVI spectra also provides direct evidence of vibronic coupling between ground and electronically excited states of methoxy.