Implication of Amyloid Precursor-like Protein 2 Expression in Cutaneous Squamous Cell Carcinoma Pathogenesis.

BACKGROUND/AIM: Regulatory functions of amyloid precursor-like protein 2 (APLP2) expression in intracellular trafficking of major histocompatibility complex class I (MHC-I) and biological behavior of tumor cells have been reported in various types of malignancies but not in cutaneous squamous cell carcinoma (CSCC). This study aimed to investigate the role of APLP2 expression in the pathogenesis of CSCC. PATIENTS AND METHODS: The expression of APLP2 and a key modulator of cancer immune escape, MHC-I, were determined in CSCC tissue samples obtained from 141 patients using immunohistochemistry. The regulatory effects of APLP2 expression on the biological behavior and surface expression of MHC-I in CSCC cells were investigated by trypan blue assay, Matrigel invasion assay, and in vivo xenograft analysis. RESULTS: APLP2 immunoreactivity was high in 73 (51.8%) tissue samples from patients with CSCC and was significantly related to subcutaneous fat invasion and poor prognosis in our cohort. Moreover, proliferation of and invasion by CSCC cells were significantly reduced after APLP2 knockdown in CSCC cells both in vitro and in vivo. A significant association was found between APLP2 and membrane MHC-I expression in patients with CSCC. In vivo xenograft analysis showed that APLP2 knockdown increased membrane MHC-I expression in CSCC cells. CONCLUSION: APLP2 not only acts as an oncogene in CSCC progression but also as a possible modulator of cancer immune escape by influencing MHC-I expression on the cell surface. APLP2 may serve as a novel molecular biomarker and therapeutic target for patients with CSCC.

Implication of TIPE2 Expression on the Malignant Transformation of Oral Leukoplakia.

BACKGROUND/AIM: Identification of biomarkers involved in the malignant transformation of oral leukoplakia (OL) is required for the early diagnosis and management of patients with OL. This study aimed to evaluate the functions of tumor necrosis factor-alpha-induced protein 8-like 2 (TIPE2) expression in the malignant transformation of OL. MATERIALS AND METHODS: The expression levels of TIPE2 and dormant cell markers phospho-ERK and phospho-p38 in a cohort containing 103 surgical specimens from patients with OL were evaluated using immunohistochemistry. The influence of TIPE2 expression on the biological behavior of the immortalized human oral keratinocyte (IHOK) line was investigated in vitro. RESULTS: Increased TIPE2 expression was detected in 40 (38.8%) patients with OL. In a multivariate analysis using clinicopathological variables and TIPE2 expression as cofactors, the presence of dysplasia (p=0.003) and TIPE2 abundance (p=0.019) were identified as independent risk factors for the malignant transformation of OL. Moreover, the in vitro analysis revealed that TIPE2 knockdown can promote the proliferating ability of IHOK; however, the number of apoptotic cells also increased after TIPE2 knockdown in IHOK. Furthermore, TIPE2 expression was significantly associated with phospho-p38 expression, a dormant cell marker, in our cohort (p=0.047). CONCLUSION: TIPE2 expression may contribute to the malignant transformation of OL, and its function may be related to cellular dormancy in OL pathogenesis.

Commercial dynamics in urban China during the COVID-19 recession: Vulnerability and short-term adaptation of commercial centers in Shanghai.

Studying the commercial dynamics during the COVID-19 recession could help deepen our understanding of how the pandemic damages the commercial economy and how to against the pandemic. This study aims to explore the vulnerability and adaptation of commercial centers using a weekly consumption data of UnionPay cards in Shanghai. A vulnerability index and multiscale geographically weighted regressions (MGWR) are employed. Our results suggest that retail, leisure, and entertainment sectors are less vulnerable to the pandemic at the early stage, when catering, life service, and wholesale sectors are more influenced. Catering, life service, and wholesale sectors were better adapted to the second wave of the pandemic, while the retail and entertainment sectors were even more vulnerable. Further analysis using MGWR models suggests that the commercial centers with higher consumption volume are better adapted to the shock. The diversity of commercial sectors mainly reduces low-level commercial centers' vulnerability to the pandemic. The commercial centers targeting high-end consumers with wider hinterland were less adapted to the pandemic. These research outcomes reveal the disparities in commercial centers' vulnerability against COVID-19 and highlight adaptation's role during the pandemic.

A nomogram combining clinical factors and biomarkers for predicting the recurrence of high-risk cutaneous squamous cell carcinoma.

BACKGROUND: Although determining the recurrence of cutaneous squamous cell carcinoma (cSCC) is important, currently suggested systems and single biomarkers have limited power for predicting recurrence. OBJECTIVE: In this study, combinations of clinical factors and biomarkers were adapted into a nomogram to construct a powerful risk prediction model. METHODS: The study included 145 cSCC patients treated with Mohs micrographic surgery. Clinical factors were reviewed, and immunohistochemistry was performed using tumor tissue samples. A nomogram was constructed by combining meaningful clinical factors and protein markers. RESULTS: Among the various factors, four clinical factors (tumor size, organ transplantation history, poor differentiation, and invasion into subcutaneous fat) and two biomarkers (Axin2 and p53) were selected and combined into a nomogram. The concordance index (C-index) of the nomogram for predicting recurrence was 0.809, which was higher than that for the American Joint Committee on Cancer (AJCC) 7th, AJCC 8th, Brigham and Women's Hospital, and Breuninger staging systems in the patient data set. CONCLUSION: A nomogram model that included both clinical factors and biomarkers was much more powerful than previous systems for predicting cSCC recurrence.

Implication of IL6-positive Cancer-associated Fibroblasts in Merkel Cell Carcinoma Pathogenesis: A Possible Modulator of Immune Microenvironment.

BACKGROUND/AIM: The role of cancer-associated fibroblasts (CAFs) in the pathogenesis of Merkel cell carcinoma (MCC) remains unknown. This study aimed to investigate the clinicopathological significance of CAF subpopulations and their association with tumor-infiltrating lymphocytes (TILs) in patients with MCC. MATERIALS AND METHODS: Clinicopathological features and the status of microenvironment fibrosis (MF) around tumor masses were evaluated in 20 MCC patient and tissue sections. Alpha-smooth muscle actin (α-SMA)-positive CAFs (α-SMA+CAFs), interleukin-6-positive CAFs (IL6+CAFs), CD4-positive TILs (CD4+TILs), and CD8-positive TILs (CD8+TILs) in MCC tissue samples were investigated using immunohistochemistry. RESULTS: In a total of 20 MCC patients, high-MF was detected in 12 (60%) patients which was significantly associated with worse progression-free survival (p=0.048), but not with overall survival. CD4+/CD8+ TILs were frequently detected in MCC tissues. High-intra-tumoral CD8+TIL was significantly associated with better overall and progression-free survival (p=0.04 and p=0.015) in our cohort. High-αSMA+ CAFs were detected in 11 (55.0%) patients and high-IL6+CAFs in 10 (50.0%) patients. A negative association was found between high-IL6+CAF and high-intra-tumoral CD8+TILs (p=0.005). Patients with high IL6+CAFs showed worse overall/progression-free survival than patients with low-IL6+CAFs (p=0.022 and p=0.035). CONCLUSION: IL6+CAFs may largely influence the tumor immune microenvironment of MCC by modulating distinct T-cell populations and functions. This study provides a possible therapeutic target to overcome resistance to immune therapies in MCC.

Identification of combined biomarkers for predicting the risk of osteoporosis using machine learning.

Osteoporosis is a severe chronic skeletal disorder that affects older individuals, especially postmenopausal women. However, molecular biomarkers for predicting the risk of osteoporosis are not well characterized. The aim of this study was to identify combined biomarkers for predicting the risk of osteoporosis using machine learning methods. We merged three publicly available gene expression datasets (GSE56815, GSE13850, and GSE2208) to obtain expression data for 6354 unique genes in postmenopausal women (45 with high bone mineral density and 45 with low bone mineral density). All machine learning methods were implemented in R, with the GEOquery and limma packages, for dataset download and differentially expressed gene identification, and a nomogram for predicting the risk of osteoporosis was constructed. We detected 378 significant differentially expressed genes using the limma package, representing 15 major biological pathways. The performance of the predictive models based on combined biomarkers (two or three genes) was superior to that of models based on a single gene. The best predictive gene set among two-gene sets included PLA2G2A and WRAP73. The best predictive gene set among three-gene sets included LPN1, PFDN6, and DOHH. Overall, we demonstrated the advantages of using combined versus single biomarkers for predicting the risk of osteoporosis. Further, the predictive nomogram constructed using combined biomarkers could be used by clinicians to identify high-risk individuals and in the design of efficient clinical trials to reduce the incidence of osteoporosis.

Weight-bearing activity impairs nuclear membrane and genome integrity via YAP activation in plantar melanoma.

Acral melanoma commonly occurs in areas that are not exposed to much sunlight, such as the sole of the foot. Little is known about risk factors and mutational processes of plantar acral melanoma. Nuclear envelope rupture during interphase contributes to genome instability in cancer. Here, we show that the nuclear and micronuclear membranes of melanoma cells are frequently ruptured by macroscopic mechanical stress on the plantar surface due to weight-bearing activities. The marginal region of plantar melanoma nodules exhibits increased nuclear morphological abnormalities and collagen accumulations, and is more susceptible to mechanical stress than the tumor center. An increase in DNA damage coincides with nuclear membrane rupture in the tumor margin. Nuclear envelope integrity is compromised by the mechanosensitive transcriptional cofactor YAP activated in the tumor margin. Our results suggest a mutagenesis mechanism in melanoma and explain why plantar acral melanoma is frequent at higher mechanical stress points.

Prediction of Chemosensitivity in Multiple Primary Cancer Patients Using Machine Learning.

BACKGROUND/AIM: Many cancer patients face multiple primary cancers. It is challenging to find an anticancer therapy that covers both cancer types in such patients. In personalized medicine, drug response is predicted using genomic information, which makes it possible to choose the most effective therapy for these cancer patients. The aim of this study was to identify chemosensitive gene sets and compare the predictive accuracy of response of cancer cell lines to drug treatment, based on both the genomic features of cell lines and cancer types. MATERIALS AND METHODS: In this study, we identified a gene set that is sensitive to a specific therapeutic drug, and compared the performance of several predictive models using the identified genes and cancer types through machine learning (ML). To this end, publicly available gene expression datasets and drug sensitivity datasets of gastric and pancreatic cancers were used. Five ML algorithms, including linear discriminant analysis, classification and regression tree, k-nearest neighbors, support vector machine and random forest, were implemented. RESULTS: The predictive accuracy of the cancer type models were 0.729 to 0.763 on the training dataset and 0.731 to 0.765 on the testing dataset. The predictive accuracy of the genomic prediction models was 0.818 to 1.0 on the training dataset and 0.759 to 0.896 on the testing dataset. CONCLUSION: Performance of the specific gene models was much better than those of the cancer type models using the ML methods. Therofore, the most effective therapeutic drug can be chosen based on the expression of specific genes in patients with multiple primary cancers, regardless of cancer types.

Hypoxia and HIF-1α Regulate Collagen Production in Keloids.

Keloids are reactive or spontaneous fibroproliferative dermal tumors characterized by the exaggerated and uncontrolled accumulation of extracellular collagen. Current approaches to mitigate keloidogenesis are largely procedural in nature. However, a better understanding of its biological drivers may lead to novel targeted treatments for keloids. Through whole-genome expression analysis, we found that an HIF-1α transcriptional footprint is preferentially upregulated (activation score = 2.024; P = 1.05E-19) in keloid fibroblasts compared with normal dermal fibroblasts. We verified that HIF-1α protein is more strongly expressed in keloid specimens compared with normal skin (P = 0.035) and that hypoxia (1% O2) leads to increased collagen, especially in the extracellular compartment. Collagen levels were reduced uniformly by selective HIF-1α inhibitor CAY10585. Our results indicate that collagen secretion may be intimately linked to a hypoxic microenvironment within keloid tumors and that HIF-1α blockade could be a novel avenue of treatment for these tumors.

AXIN2 and SNAIL expression predict the risk of recurrence in cutaneous squamous cell carcinoma after Mohs micrographic surgery.

Recurrence is a common complication observed during cutaneous squamous cell carcinoma (cSCC) treatment; however, biomarkers for predicting recurrence in cSCC remain unknown. The present study aimed to investigate the predictive value of axis inhibition protein 2 (AXIN2) and SNAIL expression in cSCC recurrence. AXIN2 and SNAIL expression was evaluated using immunohistochemistry in 111 cSCC tissue samples obtained from 18 patients who presented recurrence (recurrence interval, 1-91 months) and 93 patients who did not experience recurrence following Mohs micrographic surgery (MMS) during the follow-up period (156 months). Nomogram construction was performed using patients' clinicopathological characteristics and AXIN2 and SNAIL protein expression. The results demonstrated that high AXIN2 (histoscore >100) and SNAIL (histoscore >100) expression was detected in 35 and 44 cSCC tissues, respectively. Furthermore, the expression levels of AXIN2 and SNAIL were significantly associated in patients with cSCC (P=0.001). AXIN2 and SNAIL expression levels were significantly associated with tumor size (P=0.021 and P=0.044, respectively) and recurrence of cSCC (P=0.017 and P=0.042, respectively). In addition, the results of the Kaplan-Meier curve analysis revealed that recurrence-free survival was significantly associated with tumor size (P=0.025), differentiation status (P<0.001), AXIN2 expression (P=0.001) and SNAIL expression (P=0.001). Furthermore, the results of the multivariate analysis demonstrated that age (P=0.043), AXIN2 expression (P=0.001) and SNAIL expression (P=0.045) were independent risk factors for cSCC recurrence in the present cohort. A nomogram for predicting the 1-, 2-, 3-, and 5-year recurrence-free survival was developed for patients with cSCC by including independent risk factors with a concordance index of 0.75. The results suggested that high AXIN2 and SNAIL expression may be considered as potential risk factors for cSCC recurrence. This nomogram may therefore be useful to assess the probability of recurrence in patients with cSCC following MMS.

Risk factors for recurrence in cutaneous squamous cell carcinoma after Mohs micrographic surgery: A retrospective review of 237 Asian patients.

Even after complete removal with Mohs micrographic surgery (MMS), cutaneous squamous cell carcinoma (cSCC) may recur; however, information about risk factors for recurrence in Asian patients is limited. This retrospective study reviewed cSCC patients treated with MMS at a single tertiary referral center from 2000 to 2017. Two hundred and thirty-seven patients were included and 36 showed recurrence (20 with local recurrence, 16 with distant metastasis). History of organ transplantation, diabetes, other malignancies and poorly differentiated histology correlated with cSCC recurrence. History of organ transplantation and cryotherapy at the cSCC site were related to higher local recurrence rates, and poor differentiation related to higher distant metastasis in Asian cSCC patients treated with MMS.

Overexpression and Implications of Melanoma-associated Antigen A12 in Pathogenesis of Human Cutaneous Squamous Cell Carcinoma.

BACKGROUND/AIM: Melanoma-associated antigen A12 (MAGEA12) has recently been reported as a repressor of tumor-suppressor genes. This study aimed to investigate the implications of MAGEA12 expression in the pathogenesis of cutaneous squamous cell carcinoma (cSCC). MATERIALS AND METHODS: MAGEA12 and p21 expression were investigated in 15 samples of normal skin and 111 of cSCC tissues by immunohistochemistry. The biological functions of MAGEA12 in cSCC were also investigated both in vitro and in vivo. RESULTS: Expression of both MAGEA12 and p21 was significantly increased in cSCC. MAGEA12 expression showed a positive correlation, while p21 expression showed negative correlation with the recurrence-free survival of patients with cSCC. In addition, MAGEA12 knockdown significantly attenuated proliferative, migratory, invasive, and tumorigenic activities of cSCC cells and was negatively correlated with p21 expression both in vitro and in vivo. CONCLUSION: MAGEA12-mediated down-regulation of p21 may be involved in cSCC pathogenesis and MAGEA12 may serve as a molecular biomarker in cSCC.

Low-fluenced erbium:yttrium-aluminium-garnet laser treatment in combination with broadband light pretreatment for various pigmentation disorders in Asian patients.

BACKGROUND: Low-fluenced 2940-nm erbium (Er):yttrium-aluminium-garnet (YAG) resurfacing elicits ablative photothermal tissue reactions confined to the uppermost parts of the epidermis. OBJECTIVE: To demonstrate the efficacy and safety of low-fluenced ablative Er:YAG laser treatment in combination with broadband light (BBL) pretreatment for various pigmentation disorders. METHODS: In total, 35 Korean patients with various pigmentation disorders were pretreated with BBL, and then, low-fluenced Er:YAG laser resurfacing was performed with a beam size of 4 mm and a fluence of 1.0-1.5 J/cm2 . RESULTS: An average of 1.1 ± 0.4 sessions of combined BBL and low-fluenced Er:YAG resurfacing treatment was delivered to the patients. Most post-Er:YAG scaling fell off spontaneously over 3-5 days, and most of the post-BBL crusting disappeared spontaneously over 5-7 days. At 2 months after final treatment, the mean global aesthetic improvement scale score for the clinical improvement of pigmentation lesions was estimated as 2.5 ± 0.8, and that for the improvement of overall skin tone, texture, and wrinkles was 2.8 ± 1.0. CONCLUSION: Our data demonstrated that post-BBL, low-fluenced Er:YAG laser resurfacing can be used to effectively treat various pigmentation disorders in Asian patients. Further improvements in overall skin tone, texture, and wrinkles were also achieved without major side effects.

The Pathogenic Effect of Cortactin Tyrosine Phosphorylation in Cutaneous Squamous Cell Carcinoma.

BACKGROUND/AIM: Cortactin (CTTN) has been considered a promising molecular prognostic factor in various types of cancers. In this study, we aimed to investigate the role of CTTN in the pathogenesis of cutaneous squamous cell carcinoma (CSCC). MATERIALS AND METHODS: CTTN and phospho-CTTN (p-CTTN) expression was determined in 10 healthy controls and 38 CSCC tissue samples by immunohistochemistry. The influence of CTTN on the biological behavior of CSCC cells was also investigated. RESULTS: p-CTTN expression was significantly increased in CSCC than control samples. In contrast, no significant difference in CTTN expression was found between control and CSCC tissues. Moreover, a significant association was found between recurrence-free survival with p-CTTN expression, but not with CTTN expression. Furthermore, the proliferative, migratory, and invasive abilities of CSCC cells were significantly decreased by CTTN-siRNA transfection. CONCLUSION: CTTN phosphorylation is strongly associated with CSCC pathogenesis and may serve as a molecular biomarker of CSCC.

Split-face comparison study of transcutaneous pneumatic injection therapy with isotonic and hypertonic glucose solutions.

BACKGROUND: Transcutaneous pneumatic injection (TPI) is a minimally invasive, needle-free modality that can be used to forcefully deliver solution into soft tissues of the face and scalp. OBJECTIVE: To evaluate the effects of TPI of 5% isotonic and 20% hypertonic glucose solutions in in vivo human skin for face lifting. METHODS AND MATERIALS: A prospective, split-face, evaluator-blinded comparison study was performed on 10 Korean participants who were treated with three sessions of TPI using 5% isotonic and 20% hypertonic glucose solutions. RESULTS: The following assessment parameters were improved after TPI therapy using 5% isotonic glucose solution in descending order of mean global aesthetic improvement scale (GAIS) score: perioral expression wrinkles, zygomatic wrinkles or mid-cheek furrows, eyebrow ptosis, jowl sagging, marionette line, horizontal forehead lines, nasolabial folds, and blepharochalasis. Meanwhile, TPI therapy using 20% hypertonic glucose solution improved the following assessment parameters: zygomatic wrinkles or mid-cheek furrows, perioral expression wrinkles, eyebrow ptosis, blepharochalasis, marionette line, jowl sagging, nasolabial folds, and horizontal forehead lines. Linear mixed models revealed a significant interaction between treatment groups and time. CONCLUSION: Our data demonstrated that TPI treatment with 20% hypertonic glucose solution elicited earlier and more pronounced therapeutic responses, compared to 5% isotonic glucose solution.

Therapeutic efficacy and safety of a 1927-nm fractionated thulium laser on pattern hair loss: an evaluator-blinded, split-scalp study.

Laser- or light-assisted therapies have been used to improve the perifollicular environment by upregulating the expression of growth factors and signaling molecules for hair restoration. The aim of our study was to preclinically and clinically evaluate the therapeutic efficacy and safety of a 1927-nm fractionated thulium laser on pattern hair loss (PHL). An in vivo hairless mouse study and an in vivo human skin environmental scanning electron microscopy (ESEM) study were performed with different power and energy settings. Thereafter, an evaluator-blinded, split-scalp study was conducted to evaluate hair thickness and density in 10 PHL patients treated with 12 sessions of fractionated thulium laser treatment with or without post-laser treatment application of a growth factor-containing (GF) solution. In in vivo hairless mouse skin, inverted cone-shaped zones of thulium laser-induced tissue coagulation (LITC) were noted immediately after treatment in the epidermis and upper to mid-dermis without remarkable ablative tissue injury. The ESEM study revealed round to oval-shaped zones of non-ablative LITC on the surface of the stratum corneum of a human subject immediately after laser irradiation. In PHL patients, 12 sessions of thulium laser monotherapy at 1-week intervals resulted in significantly increased hair density and thickness. Post-laser treatment application of GF solution offered additional therapeutic efficacy by improving hair density and thickness on the split scalp. The use of a fractionated thulium laser with or without post-laser therapy application of GF solution to treat PHL elicited remarkable improvements in hair thickness and hair counts.

Snail and Axin2 expression predict the malignant transformation of oral leukoplakia.

OBJECTIVES: Oral leukoplakia (OL) has a well-documented potential risk of malignant transformation into oral squamous cell carcinoma (OSCC), although biomarker(s) predicting malignant potential are limited in capability. The aim of this cross-sectional and retrospective cohort study was to investigate the predictive role of canonical Wnt genes Axin2 and Snail (SNAI1) expression in the malignant transformation of OL lesions. MATERIALS AND METHODS: The expression of epithelial-mesenchymal transition (EMT) genes Snail and Axin2, which are regulated by the canonical Wnt pathway, were determined using immunohistochemical staining in an OL cohort consisting of 154 samples of patients with long-term follow-up and then evaluated as risk factors for malignant transformation of OL. RESULTS: Increased Axin2 and Snail abundance were found in 107 (69.5%) and 58 (37.7%) of OL patients, respectively. In a multivariate analysis using gender, age, lesion site, Axin2, and Snail as cofactors, both Axin2 and Snail were independent risk factors for malignant transformation with a hazard ratio of 7.47 (95% confidence interval, 2.23-25.02; P=0.001) and 4.41 (95% confidence interval, 1.78-10.93; P=0.001), respectively. A nomogram for predicting 5-, 10-, and 15-year cancer-free survival probability was developed in patients with OL by including gender, age, lesion site, Axin2, and Snail expression with ac-index of 0.760. CONCLUSION: The increased abundance of Snail and Axin2 is highly correlated to malignant transformation of OL, making them novel biomarker(s) predicting oral cancer development.

Nomogram for risk prediction of malignant transformation in oral leukoplakia patients using combined biomarkers.

OBJECTIVE: Squamous cell carcinomas (SCC) are the most common malignancies in the oral mucosa; these carcinomas have been preceded by potentially malignant oral disorders (PMODs), mostly oral leukoplakia (OL). No specific biomarker has been widely accepted for predicting the risk of malignant transformation of PMODs. The aim of this study was to develop an accurate prediction model for the malignant transformation of OL using clinical variables and candidate biomarkers. MATERIALS AND METHODS: To achieve this goal, 10 candidate biomarkers that had previously been reported as useful molecules were investigated: P53, Ki-67, P16, ß-catenin, c-jun, c-met, insulin like growth factor II mRNA-binding protein (IMP-3), cyclooxygenase (COX-2), podoplanin (PDPN) and carbonic anhydrase 9 (CA9). For this study, malignant transformed (n=22, median interval of malignant conversion: 3.3years) and untransformed (n=138) OL specimens with median follow-up period of 11.3years (range: 4.6-23.2years) were immunohistochemically stained. RESULTS: Using univariate Cox regression analysis, all biomarkers were proven to be significant for predicting malignant transformation in OL. To reach the highest prediction accuracy, the repeated simulation was performed, revealing that the combination of P53 and CA9 with the clinical factors including age and degree of dysplasia achieved the highest prediction accuracy. We constructed a nomogram with the identified prognostic factors for predicting the 5-, 10-, and 15-year progression free survival of OL. CONCLUSIONS: The proposed nomogram may be useful for the accurate and individual prediction of the transformation to SCC in OL patients and may help clinicians offer appropriate treatments and follow up.

Pressure- and dose-controlled transcutaneous pneumatic injection of hypertonic glucose solution for the treatment of atrophic skin disorders.

BACKGROUND: Needleless transcutaneous pneumatic injections (TPIs) are a minimally invasive way to deliver the solution into the skin for therapeutic purposes. The suggested action mechanisms of TPI therapy include mechanical stimulation, immediate tissue shrinkage and late wound healing. METHODS: Thirteen Korean patients were treated with TPI for atrophic skin disorders, including acne scars, striae albae, post-furuncle, or carbuncle scars, and horizontal wrinkles with lipoatrophy. At each TPI treatment session, a single pass was made along with the atrophic skin lesions without overlapping. Thereafter, two dermatologists objectively evaluated the clinical improvement in the lesions in the photographs via the global aesthetic improvement scale (GAIS). RESULTS: One month after the final treatment, the overall mean GAIS score was 2.3 ± 0.8. Six of the 13 (46.2%) patients exhibited clinical improvement of grade 3, five (38.5%) patients grade 2 and two (15.4%) patients grade 1. The overall mean subjective satisfaction score with the TPI treatment was 2.3 ± 0.9. Six of the 13 (46.2%) patients achieved subjective satisfaction of grade 3, six (46.2%) patients grade 2 and one (7.7%) patient grade 0. CONCLUSIONS: The present study demonstrated that the TPI treatment is effective and safe for treating atrophic skin disorders of varying causes in Korean patients.