Epigenetic repression of CHCHD2 enhances survival from single cell dissociation through attenuated Rho A kinase activity.

During in vitro culture, human pluripotent stem cells (hPSCs) often acquire survival advantages characterized by decreased susceptibility to mitochondrial cell death, known as "culture adaptation." This adaptation is associated with genetic and epigenetic abnormalities, including TP53 mutations, copy number variations, trisomy, and methylation changes. Understanding the molecular mechanisms underlying this acquired survival advantage is crucial for safe hPSC-based cell therapies. Through transcriptome and methylome analysis, we discovered that the epigenetic repression of CHCHD2, a mitochondrial protein, is a common occurrence during in vitro culture using enzymatic dissociation. We confirmed this finding through genetic perturbation and reconstitution experiments in normal human embryonic stem cells (hESCs). Loss of CHCHD2 expression conferred resistance to single cell dissociation-induced cell death, a common stress encountered during in vitro culture. Importantly, we found that the downregulation of CHCHD2 significantly attenuates the activity of Rho-associated protein kinase (ROCK), which is responsible for inducing single cell death in hESCs. This suggests that hESCs may survive routine enzyme-based cell dissociation by downregulating CHCHD2 and thereby attenuating ROCK activity. These findings provide insights into the mechanisms by which hPSCs acquire survival advantages and adapt to in vitro culture conditions.

Molecular characterization of onychomatricoma: Spatial profiling reveals the role of onychofibroblasts in its pathogenesis.

Onychomatricoma (OM) is a rare nail unit tumour with a characteristic presentation of finger-like projections arising from the nail matrix. Due to the lack of transcriptome information, the mechanisms underlying its development are largely unknown. To characterize molecular features involved in the disease pathogenesis, we used digital spatial profiling (DSP) in 2 cases of OM and normal control nail units. Based on the histological evaluation, we selectively profiled 69 regions of interest covering epithelial and stromal compartments of each tissue section. Dermoscopic and histopathologic findings were reviewed in 6 cases. Single-cell RNA sequencing of nail units and DSP were combined to define cell type contributions of OM. We identified 173 genes upregulated in stromal compartments of OM compared to onychodermis, specialized nail mesenchyme. Gene ontology analysis of the upregulated genes suggested the role of Wnt pathway activation in OM pathogenesis. We also found PLA2G2A, a known modulator of Wnt signalling, is strongly and specifically expressed in the OM stroma. The potential role of Wnt pathway was further supported by strong nuclear localization of ß-catenin in OM. Compared to the nail matrix epithelium, only a few genes were increased in OM epithelium. Deconvolution of nail unit cell types showed that onychofibroblasts are the dominant cell type in OM stroma. Altogether, integrated spatial and single-cell multi-omics concluded that OM is a tumour that derives a significant proportion of its origin from onychofibroblasts and is associated with upregulation of Wnt signals, which play a key role in the disease pathogenesis.

Histopathologic features distinguishing secondary syphilis from its mimickers.

BACKGROUND: Syphilis is often misdiagnosed clinically, and biopsies might be required. OBJECTIVE: To determine histopathologic features that distinguish secondary syphilis from pityriasis lichenoides (PL), pityriasis rosea (PR), and early mycosis fungoides (MF). METHODS: Histopathologic features of 100 cases of syphilis, 110 cases of PL, 72 cases of PR, and 101 cases of MF were compared. RESULTS: Elongated rete ridges and interstitial inflammation favor syphilis over PL (likelihood ratios 3.44 and 2.72, respectively), but no feature reliably distinguishes between them. Secondary syphilis and PR can be distinguished by neutrophils in the stratum corneum, plasma cells, interface dermatitis with lymphocytes and vacuoles, and lymphocytes with ample cytoplasm. Plasma cells and lymphocytes with ample cytoplasm are rare in early MF and can be used as distinguishing features. CONCLUSIONS: Histopathologic features characteristic of syphilis can be seen in PL, PR, and early MF. Distinguishing syphilis from PL can be difficult histologically, and a high index of suspicion is required. Although elongation of rete and interstitial inflammation favor syphilis, plasma cells (historically considered a significant feature of syphilis) are often encountered in PL. Vacuolar interface dermatitis with a lymphocyte in every vacuole is considered characteristic of PL, but this feature appears to be more common in syphilis.

Two Unusual Cases of Discoid Lupus Erythematosus Associated With Xanthomatized Macrophages.

We present 2 patients with chronic discoid lupus erythematosus (LE) associated with xanthomatized macrophages on light microscopic findings. Skin biopsies revealed hyperkeratotic and atrophic epidermis, vacuolar degeneration of the dermal-epidermal junction, thickened basement membrane, follicular plugging, and perivascular and perifollicular lymphohistiocytic infiltrate. Notably, large collections of lipid-laden histiocytes were observed within the subjacent dermis. The patients denied history of intralesional steroid treatment. The patients did not demonstrate any clinical or laboratory signs of hyperlipidemia, cholestasis, and diabetes mellitus and insipidus. Accumulation of lipid-laden foam cells in cutaneous LE is a rare phenomenon that has been reported in discoid LE and lupus panniculitis, each only once in the literature. It has also been described within lesions of various other dermatoses in patients without lipid, hepatic, or endocrine abnormalities. Its mechanism remains unclear, but it has been hypothesized that intracellular lipids released from degenerating cells contribute to lipidization of mononuclear scavengers. Xanthomatous infiltration in cutaneous LE is an unusual feature, and its presence may not necessarily signify an underlying metabolic disorder.

The concept of nail matrix onychodermis (onychomatricodermis) in the nail unit: Histology and elastin immunohistochemistry.

BACKGROUNDS: We previously demonstrated the presence of onychodermis below nail matrix and nail bed. Because nail matrix is a producer of nail plate, we hypothesized that onychodermis below nail matrix could be the nail counterpart of follicular dermal papilla. In this study, we sought to further characterize histologic, histochemical, and immunohistochemical features of nail matrix onychodermis. METHODS AND RESULTS: Hematoxylin and eosin slides of 10 polydactyly nail units and 10 nail matrix biopsies from children and adults were reviewed. In polydactyly nail units, the onychodermis beneath nail matrix was characterized by onychofibroblasts showing abundant cytoplasm, and this area was slightly separated from the undersurface of the nail matrix. Nail matrix biopsy specimens also showed similar histology in the nail matrix onychodermis. Alcian blue stain demonstrated mucin deposition in onychofibroblasts within the nail matrix onychodermis. Immunohistochemically, elastin was rarely expressed in the nail matrix onychodermis while it was strongly expressed in the dermis of other areas of polydactyly nail units. Elastin was not expressed in follicular dermal papilla of terminal hair follicles of the scalp. CONCLUSION: Our findings demonstrate the presence and localization of nail matrix onychodermis (onychomatricodermis). Our study also demonstrates similar elastin expression patterns in the onychomatricodermis and follicular dermal papilla.

Clinicopathologic features of 28 cases of nail matrix nevi (NMNs) in Asians: Comparison between children and adults.

BACKGROUND: Clinical distinction between nail matrix nevus (NMN) and subungual melanoma (SUM) can be challenging. More precise delineation of the clinicodermoscopic characteristics specific for NMNs is needed. OBJECTIVE: We sought to analyze the clinicopathologic features of childhood and adult NMNs and to propose clinicodermoscopic features that can aid in differentiating NMNs from SUM. METHODS: We retrospectively reviewed clinical, dermoscopic, and histologic findings of patients (20 children and 8 adults) in whom NMN was diagnosed between 2012 and 2015. RESULTS: Except for 2 cases of total melanonychia, the affected nails demonstrated longitudinal melanonychia sharply demarcated from the adjacent nail plate. Melanonychia was wider among children than among adults (P = .002). Nail dystrophy was more frequent in wider lesions (P = .028). Hutchinson's sign was observed in pediatric cases at the hyponychium and/or proximal nailfold cuticles. All hyponychial pigmentations demonstrated a longitudinal brush pigmentation pattern under dermoscopy. LIMITATIONS: This was a retrospective study of Asians in a single center. CONCLUSION: Our study is the largest case series to date of biopsy-confirmed NMNs. It highlighted important clinicodermoscopic differences between pediatric and adult NMNs. We propose that in pediatric cases of longitudinal melanonychia presenting as a sharply demarcated pigment band of even width, the presence of Hutchinson's sign with longitudinal brush pigmentation may favor a diagnosis of NMN over SUM.

CD13 is a marker for onychofibroblasts within nail matrix onychodermis: Comparison of its expression patterns in the nail unit and in the hair follicle.

BACKGROUND: We previously demonstrated the presence of onychodermis, a specialized mesenchymal cell population beneath the nail matrix and proximal nail bed demonstrating CD10 expression. We hypothesize that the onychodermis could be the nail analog of the follicular dermal papilla, which is known to express CD13. We compare CD13 expression patterns between specialized mesenchymes of nail and hair, and compare these findings with CD10 expression patterns. METHODS: CD10 and CD13 immunohistochemistry was performed on polydactyly and adult cadaveric nail units, and on hair follicles in scalp nevus sebaceus excision specimens. RESULTS: CD10 and CD13 were expressed in the mesenchyme below the nail matrix and nail bed. Stronger CD13 expression was observed in the mesenchyme containing onychofibroblasts below the nail matrix compared with that below the nail bed. CD10 was expressed in the dermal sheath of terminal hair follicles, but it was expressed in the dermal sheath and follicular dermal papilla of primitive hair follicles within nevus sebaceus lesions. CD13 was expressed in the dermal sheath and dermal papilla of terminal and primitive hair follicles. CONCLUSION: CD13 may be a marker for onychofibroblasts within nail matrix onychodermis. We demonstrate CD13 expression in the specialized mesenchymes of both nail and hair.

Diagnostic Criteria in Intraepithelial Pagetoid Neoplasms: A Histopathologic Study and Evaluation of Select Features in Paget Disease, Bowen Disease, and Melanoma In Situ.

BACKGROUND: Paget disease, Bowen disease, and malignant melanoma in situ are intraepidermal neoplasms, characterized by the presence of pagetoid scatter of atypical cells in the epidermis. This study reviewed the frequency of select histologic criteria to validate their usefulness in the histologic distinction between these entities. METHODS: One hundred forty-four specimens with the diagnosis of Bowen disease, 144 specimens with Paget disease (mammary and extramammary), and 144 specimens with malignant melanoma in situ were examined microscopically to define frequencies of select histologic criteria present in each disease. RESULTS: Comparison between mammary Paget and extramammary Paget disease showed no significant differences in the features studied. Crushing of basal keratinocytes, presence of atypical cells in the corneum, and presence of large cells with amphophilic cytoplasm were significantly noted in Paget disease. Transition between the atypical clear cells and surrounding keratinocytes was absent in all cases of melanoma in situ and in 87 (60.4%) cases of Paget disease, but it was significantly associated with Bowen disease (98.6%). Dyskeratotic cells were significantly associated with Bowen disease cases. CONCLUSION: Our study demonstrated a practical histologic approach to differentiate between intraepidermal pagetoid neoplasms. Careful histologic study of the proposed criteria may reduce reliance on immunohistochemical stains.

Specificity of granular IgM deposition in folliculosebaceous units and sweat gland apparatus in direct immunofluorescence (DIF) of lupus erythematosus.

BACKGROUND: Diagnosis of lupus erythematosus (LE) in direct immunofluorescence testing is based on the finding of positive immunofluorescence at the dermoepidermal junction (DEJ). OBJECTIVES: We sought to evaluate the sensitivity of IgM deposition at the DEJ and adnexal structures in the diagnosis of lupus erythematosus. METHODS: We conducted a retrospective study of 100 previously diagnosed cases of lupus erythematosus and 158 cases of other immune-mediated dermatosis. Deposition of IgG, IgM, IgA, and C3 at the DEJ, follicular units, and sweat glands were recorded. Presence or absence of adnexal structures was documented. The immunoreactant deposition was documented as linear, coarse granular, or stippled. RESULTS: The most frequently deposited immunoreactant in lupus erythematosus cases was IgM along the DEJ and stromal-epithelial junction of hair follicles and sweat glands. IgM deposition along the stromal-epithelial junction of hair follicles and sweat glands was strongly associated with a diagnosis of lupus erythematosus compared with other immune-mediated diseases collectively (P value < .001). The pattern of IgM in lupus and dermatomyositis is granular, in contrast to the linear deposition in the other disorders evaluated. LIMITATIONS: This was a retrospective study of archived material. CONCLUSION: Granular IgM deposition at the stromal-epithelial junction of cutaneous adnexal structures suggests a diagnosis of lupus erythematosus or dermatomyositis.

Histologic features of secondary syphilis: A multicenter retrospective review.

BACKGROUND: Secondary syphilis has a wide spectrum of clinical and histologic manifestations. OBJECTIVE: We sought to determine the frequency of histopathological features characterizing secondary syphilis, and which are most common in specimens displaying few diagnostic findings. METHODS: In a multicenter, retrospective analysis of biopsy-proven secondary syphilis, cases were subcategorized by the number of histologic characteristics present. RESULTS: The 106 cases mostly had 5 to 7 of the features studied. Many features were scarcer in cases with 5 or fewer features, including endothelial swelling (87.7% overall vs 72.4% ≤5 features), plasma cells (69.8% vs 48.3%), and elongated rete ridges (75.5% vs 27.6%). Specimens with 5 or fewer features were more likely to be truncal (61.1% vs 34.4% overall), demonstrate rete ridge effacement (44.8% vs 19.8%), and have pityriasis rosea (33.3% vs 17.2%) or drug eruption (33.3% vs 10.9%) in the clinical differential. An interstitial inflammatory pattern was the most common characteristic of specimens with 5 or fewer features (75.9%). LIMITATIONS: This was a retrospective review. CONCLUSION: The independent value of many histologic features of syphilis may be overestimated. Combinations of endothelial swelling, interstitial inflammation, irregular acanthosis, and elongated rete ridges should raise the possibility of syphilis, along with the presence of vacuolar interface dermatitis with a lymphocyte in nearly every vacuole and lymphocytes with visible cytoplasm.

Herpes zoster granulomatous dermatitis: histopathologic findings in a case series.

Several types of cutaneous reactions have been reported to arise at the site of herpes zoster (HZ) infection weeks to years after the acute disease. Among these, granulomatous reactions are the most frequently reported. In this study, we describe the spectrum of histopathologic findings of HZ granulomatous reactions observed in 26 patients with cutaneous lesions confined to the area of previous HZ eruption and compare them with biopsy specimens taken from 25 patients with acute HZ. All patients with persistent reactions from whom history was available presented within 12 weeks of the onset of the acute eruption. The most frequent findings were interstitial granulomatous dermatitis with lymphocytes, histiocytes and multinucleated giant cells displaying elastophagocytosis and a perineural, perivascular and perieccrine mononuclear inflammatory infiltrate rich in lymphocytes and plasma cells. Less common features included intra-arrector and peri-arrector pili granulomas, follicular dilatation and hyperkeratosis, and vasculitis. Specimens from patients with acute HZ were found to have small numbers of perineural plasma cells and most had subtle granulomatous inflammation, in patterns similar to the group with late granulomatous reactions. Our findings suggest that granulomatous reactions to varicella zoster virus represent a persistent evolving inflammatory reaction after acute infection.

Systematic omics analysis identifies CCR6 as a therapeutic target to overcome cancer resistance to EGFR inhibitors.

Epidermal growth factor receptor inhibitors (EGFRi) have exhibited promising clinical outcomes in the treatment of various cancers. However, their widespread application has been limited by low patient eligibility and the emergence of resistance. Leveraging a multi-omics approach (>1000 cancer cell lines), we explored molecular signatures linked to EGFRi responsiveness and found that expression signatures involved in the estrogen response could recapitulate cancer cell dependency on EGFR, a phenomenon not solely attributable to EGFR-activating mutations. By correlating genome-wide function screening data with EGFRi responses, we identified chemokine receptor 6 (CCR6) as a potential druggable target to mitigate EGFRi resistance. In isogenic cell models, pharmacological inhibition of CCR6 effectively reversed acquired EGFRi resistance, disrupting mitochondrial oxidative phosphorylation, a cellular process commonly associated with therapy resistance. Our data-driven strategy unveils drug-response biomarkers and therapeutic targets for resistance, thus potentially expanding EGFRi applicability and efficacy.

Development and Feasibility Evaluation of Smart Cancer Care 2.0 Based on Patient-Reported Outcomes for Post-Discharge Management of Patients with Cancer.

Purpose: A "Smart Cancer Care" platform that integrates patient-reported outcomes (PROs) with management has been established in Korea. This study focused on improving health behaviors and connecting patients to welfare services by introducing and assessing the feasibility of "Smart Cancer Care 2.0," an enhanced version designed for monitoring complications post-cancer treatment. Materials and Methods: Smart Cancer Care 2.0 was developed by conducting a literature review and consulting with expert panels to identify symptoms or variables requiring monitoring and management guidelines based on the treatment type. Qualitative and quantitative surveys were conducted to assess the feasibility of the app and web system based on the experiences of patients with cancer and healthcare workers. Results: A total of 81 symptoms or variables (chemotherapy-, surgery-, radiotherapy-, rehabilitation-, and health management-related) were selected for management in Smart Cancer Care 2.0. PROs for these symptoms were basically categorized into three severity grades: (1) preventive management, (2) self-treatment, and (3) consultation with a healthcare worker or visit to a healthcare institution. The overall mean scores in the feasibility evaluation by patients and healthcare workers were 3.83 and 3.90 points, respectively, indicating high usefulness. Conclusion: Smart Cancer Care 2.0 leverages the existing ICT-based platform, Smart Cancer Care, and further includes health behaviors and welfare services. Smart Cancer Care 2.0 may play a crucial role in establishing a comprehensive post-discharge management system for patients with cancer as it provides suitable interventions based on patients' responses and allows the regularly collected PROs to be easily viewed for streamlined care.

The utility of C4d immunohistochemistry on formalin-fixed paraffin-embedded tissue in the distinction of polymorphic eruption of pregnancy from pemphigoid gestationis.

Polymorphic eruption of pregnancy (PEP), formerly known as pruritic urticarial papules and plaques of pregnancy, is a dermatosis of pregnancy that must be distinguished from pemphigoid gestationis (PG). Although this differential diagnosis may be possible on routine histology, an additional biopsy for direct immunofluorescence (DIF) is often needed. Recent studies have demonstrated the utility of anti-C4d or anti-C3d antibodies in the diagnosis of bullous pemphigoid (BP) in formalin-fixed paraffin-embedded tissue (FFPE). We investigated the utility of routine immunohistochemistry (IHC) for anti-C4d in FFPE tissue in the specific differential diagnosis of PEP versus PG in known, DIF-proven cases. We performed C4d IHC on PEP (n = 11), PG (n = 8), DIF-proven BP (n = 12), and other common dermatoses (n = 12) that are typically DIF negative. None of the PEP cases (0/11) or the other common dermatoses (0/12) demonstrated C4d positivity at the basement membrane zone. In comparison, 100% of PG cases (8/8) and 83.3% of BP cases (10/12) showed linear C4d immunoreactant deposition along the basement membrane zone. The results demonstrate the potential utility of C4d IHC in FFPE tissue for distinguishing PEP from PG, thus potentially obviating the need of a repeat biopsy for DIF, particularly in C4d-negative cases where there is a low suspicion of PG on both clinical and histological grounds. Also, patients with positive C4d-positive immunoreactivity may also potentially proceed directly to less invasive serological confirmatory testing, such as BP180 NC16a enzyme-linked immunoabsorbent assay.

TPX2 prompts mitotic survival via the induction of BCL2L1 through YAP1 protein stabilization in human embryonic stem cells.

Genetic alterations have been reported for decades in most human embryonic stem cells (hESCs). Survival advantage, a typical trait acquired during long-term in vitro culture, results from the induction of BCL2L1 upon frequent copy number variation (CNV) at locus 20q11.21 and is one of the strongest candidates associated with genetic alterations that occur via escape from mitotic stress. However, the underlying mechanisms for BCL2L1 induction remain unknown. Furthermore, abnormal mitosis and the survival advantage that frequently occur in late passage are associated with the expression of BCL2L1, which is in locus 20q11.21. In this study, we demonstrated that the expression of TPX2, a gene located in 20q11.21, led to BCL2L1 induction and consequent survival traits under mitotic stress in isogenic pairs of hESCs and human induced pluripotent stem cells (iPSCs) with normal and 20q11.21 CNVs. High Aurora A kinase activity by TPX2 stabilized the YAP1 protein to induce YAP1-dependent BCL2L1 expression. A chemical inhibitor of Aurora A kinase and knockdown of YAP/TAZ significantly abrogated the high tolerance to mitotic stress through BCL2L1 suppression. These results suggest that the collective expression of TPX2 and BCL2L1 from CNV at loci 20q11.21 and a consequent increase in YAP1 signaling promote genome instability during long-term in vitro hESC culture.

In Silico Discovery of 5'-Modified 7-Deoxy-7-ethynyl-4'-thioadenosine as a HASPIN Inhibitor and Its Synergistic Anticancer Effect with the PLK1 Inhibitor.

Despite genetic perturbations resulting in embryo lethality for most mitotic kinases, loss of the histone H3 mitotic kinase HASPIN reveals no adverse effect in mice models, establishing HASPIN as a promising target for anticancer therapy. However, developing a HASPIN inhibitor from conventional pharmacophores poses a technical challenge as this atypical kinase shares slight similarities with eukaryotic protein kinases. Chemically modifying a cytotoxic 4'-thioadenosine analogue through high genotoxicity yielded several novel nongenotoxic kinase inhibitors. In silico apporoaches utilizing transcriptomic and chemical similarities with known compounds and KINOMEscan profiles unveiled the HASPIN inhibitor LJ4827. LJ4827's specificity and potency as a HASPIN inhibitor were verified through in vitro kinase assay and X-ray crystallography. HASPIN inhibition by LJ4827 reduced histone H3 phosphorylation and impeded Aurora B recruitment in cancer cell centromeres but not in noncancer cells. Through transcriptome analysis of lung cancer patients, PLK1 was determined as a druggable synergistic partner to complement HASPIN inhibition. Chemical or genetic PLK1 perturbation with LJ4827 effectuated pronounced lung cancer cytotoxicity in vitro and in vivo. Therefore, LJ4827 is a novel anticancer therapeutic for selectively impeding cancer mitosis through potent HASPIN inhibition, and simultaneous HASPIN and PLK1 interference is a promising therapeutic strategy for lung cancer.