Differential efficacy of tyrosine kinase inhibitors according to the types of EGFR mutations and agents in non-small cell lung cancer: a real-world study.

BACKGROUND: Both first and second-generation EGFR-TKIs are recommended in advanced NSCLC with common EGFR mutations. However, there are few data on the difference in efficacy of EGFR-TKIs based on the type of EGFR mutation and agents. METHODS: This retrospective real-world study evaluated the outcomes and clinicopathologic characteristics, including the type of EGFR mutations, of 237 advanced NSCLC patients treated with first- or second-generation (afatinib) EGFR-TKIs as first-line therapy. RESULTS: The median progression-free survival (PFS) and overall survival (OS) of all patients were 11 months (M) and 25M, respectively. In the univariate analysis, patients with exon 19 deletion (del) (n=130) had significantly longer median OS compared to those with other mutations (L858R: 84, others: 23) (30 vs. 22 M, p=0.047), without a difference in PFS (p=0.138). Patients treated with afatinib (n=60) showed significantly longer median OS compared to those treated with first-generation TKIs (gefitinib: 159, erlotinib: 18) (30 vs. 23 M, p=0.037), without a difference in PFS (p=0.179). In patients with exon 19 del, there was no significant difference in median PFS (p=0.868) or OS (p=0.361) between patients treated with afatinib and those treated with first-generation TKIs, while significantly better PFS (p=0.042) and trend in OS (p=0.069) were observed in patients receiving afatinib in other mutations. Exon 19 del was independently associated with favorable OS (p=0.028), while age >70 years (p=0.017), ECOG performance status ≥2 (p=0.001), primary metastatic disease (p=0.007), and synchronous brain metastasis (p=0.026) were independent prognostic factors of poor OS. CONCLUSIONS: The EGFR exon 19 del was associated with favorable OS in advanced NSCLC patients receiving first-line EGFR-TKIs. Moreover, in patients with exon 19 del, first-generation TKIs seem to be a reasonable treatment option if osimertinib is unavailable.

Thromboembolic events in patients who received adjuvant chemotherapy for gastric cancer: a single-center retrospective study.

BACKGROUND: Thromboembolic events (TEEs) are significant adverse events that can cause serious morbidities and mortality in cancer patients receiving chemotherapy. Patients with gastric cancer (GC) treated with palliative chemotherapy have been reported to experience a TEE incidence of 5-27%. However, very few reports have addressed TEEs in adjuvant chemotherapy (AC) for GC. METHODS: This study retrospectively analyzed 611 GC patients (stage II: 309, III: 302) who started AC with capecitabine/oxaliplatin (167 patients) or S-1 (444 patients) after undergoing curative resection between January 2013 and June 2020 at a single center. The incidence of TEEs during AC or within 1 year after AC completion was investigated, while analyzing the factors that influenced the TEEs' occurrence. RESULTS: TEEs were confirmed in 20 patients (3.3%), and TEEs occurred in almost all patients in the S-1 group (19 patients). The most common TEE types were cerebral infarction and pulmonary thromboembolism (five patients each). Although old age (≥ 70 years, p < 0.0001), S-1 treatment (p = 0.021), and hypertension (p = 0.017) were identified as significant risk factors for TEEs in univariate analysis, only old age showed a statistically significant correlation with TEEs' occurrence in multivariate analysis (odds ratio: 3.07; 95% confidence interval 1.11-8.48; p = 0.031). CONCLUSIONS: TEEs occurred in fewer patients with GC who had been treated with AC than patients who had received palliative chemotherapy in previous reports. However, elderly GC patients who are undergoing AC require more careful surveillance for possible TEEs, considering relatively higher incidence of them.

The chromatin remodeler RSF1 coordinates epigenetic marks for transcriptional repression and DSB repair.

DNA lesions impact on local transcription and the damage-induced transcriptional repression facilitates efficient DNA repair. However, how chromatin dynamics cooperates with these two events remained largely unknown. We here show that histone H2A acetylation at K118 is enriched in transcriptionally active regions. Under DNA damage, the RSF1 chromatin remodeling factor recruits HDAC1 to DSB sites. The RSF1-HDAC1 complex induces the deacetylation of H2A(X)-K118 and its deacetylation is indispensable for the ubiquitination of histone H2A at K119. Accordingly, the acetylation mimetic H2A-K118Q suppressed the H2A-K119ub level, perturbing the transcriptional repression at DNA lesions. Intriguingly, deacetylation of H2AX at K118 also licenses the propagation of γH2AX and recruitment of MDC1. Consequently, the H2AX-K118Q limits DNA repair. Together, the RSF1-HDAC1 complex controls the traffic of the DNA damage response and transcription simultaneously in transcriptionally active chromatins. The interplay between chromatin remodelers and histone modifiers highlights the importance of chromatin versatility in the maintenance of genome integrity.

Analysis of treatment outcomes according to the cycles of adjuvant chemotherapy in gastric cancer: a retrospective nationwide cohort study.

BACKGROUND: One-year S-1 or six-month capecitabine/oxaliplatin (CAPOX) has been the standard adjuvant chemotherapy for gastric cancer (GC). We investigated outcomes according to the cycles of adjuvant chemotherapy, using data from the Korean Health Insurance and Assessment Service. METHODS: A total of 20,552 patients, including 13,614 patients who received S-1 and 6,938 patients who received CAPOX extracted from 558,442 patients were retrospectively analyzed. The five-year overall survival rate was evaluated according to the duration of adjuvant chemotherapy. RESULTS: The five-year overall survival rate gradually increased according to the increase in adjuvant chemotherapy cycles in both the S-1 (≤ 5 cycles: 48.4%, hazard ratio [HR] 4.06, 95% confidence interval [CI] 3.74-4.40, P < 0.0001; 5 < cycles ≤ 6: 55.4%, HR 3.08, 95% CI 2.65-3.57, P < 0.0001; 6 < cycles ≤ 7: 64.1%, HR 2.11, 95% CI 1.84-2.41, P < 0.0001; 7 < cycles < 8: 71.1%, HR 1.60, 95% CI 1.39-1.84, P < 0.0001; ≥ 8 cycles: 77.9%) and the CAPOX groups (≤ 4 cycles: 43.5%, HR 3.20, 95% CI 2.84-3.61, P < 0.0001; 5 cycles: 45.3%, HR 2.63, 95% CI 2.11-3.27, P < 0.0001; 6 cycles: 47.1%, HR 2.09, 95% CI 1.76-2.49, P < 0.0001; 7 cycles: 55.3%, HR 1.63, 95% CI 1.35-1.96, P < 0.0001; ≥ 8 cycles: 67.2%). CONCLUSIONS: Reducing the treatment cycles of adjuvant chemotherapy in GC with S-1 or CAPOX showed inferior survival outcomes. Completing the standard duration of adjuvant chemotherapy with S-1 or CAPOX would be strongly recommended.

Trastuzumab-based palliative chemotherapy for HER2-positive gastric cancer: a single-center real-world data.

BACKGROUND: Since the results of the ToGA trial were published, trastuzumab-based chemotherapy has been used as the standard first-line treatment for HER2-positive recurrent or primary metastatic gastric cancer (RPMGC). However, the real-world data has been rarely reported. Therefore, we investigated the outcomes of trastuzumab-based chemotherapy in a single center. METHODS: This study analyzed the real-world data of 47 patients with HER2-positive RPMGC treated with trastuzumab-based chemotherapy in a single institution. RESULTS: With the median follow-up duration of 18.8 months in survivors, the median overall survival (OS) and progression-free survival were 12.8 and 6.9 months, respectively, and the overall response rate was 64%. Eastern Cooperative Oncology Group performance status 2 and massive amount of ascites were independent poor prognostic factors for OS, while surgical resection before or after chemotherapy was associated with favorable OS, in multivariate analysis. In addition, 5 patients who underwent conversion surgery after chemotherapy demonstrated an encouraging median OS of 30.8 months, all with R0 resection. CONCLUSIONS: Trastuzumab-based chemotherapy in patients with HER2-positive RPMGC in the real world demonstrated outcomes almost comparable to those of the ToGA trial. Moreover, conversion surgery can be actively considered in fit patients with a favorable response after trastuzumab-based chemotherapy.

Early removal of central venous catheter may not impact the in-hospital mortality in patients with acute leukemia.

Central venous catheters (CVCs) are generally required for chemotherapy in patients with acute leukemia, but catheter-related infection is one of the common causes of neutropenic fever. We investigated the in-hospital mortality according to early removal of CVCs and the factors influencing the mortality in patients with acute leukemia undergoing remission induction chemotherapy. This study retrospectively analyzed the hospital record data of 278 patients with acute leukemia treated with non-tunneled CVCs and remission induction chemotherapy in a single institution. Bloodstream infection was more common (p < 0.0001) and median peak C-reactive protein (CRP) levels after neutropenic fever were significantly higher (23.3 vs. 14.5 mg/dl, p = 0.003) in the group with early removal than in the group with maintenance of the CVC. Multivariate analysis of the patients revealed a significant decrease in the mortality with female gender (odds ratio (OR): 0.19, 95% confidence interval (CI): 0.06-0.54, p = 0.002) and a significant increase in the mortality according to the peak CRP (OR 1.12, 95% CI: 1.07-1.17, p < 0.0001). By contrast, early removal of the CVC had no significant effect on the mortality (OR = 1.16, 95% CI: 0.54-2.47, p = 0.706) in univariate analysis. Furthermore, subsequent bloodstream infection after clinical decision for maintenance or early removal of the CVC was confirmed more frequently in the group with early removal (early removal, 22.6%; maintenance, 7.6%, p < 0.0001). Early removal of the CVC had no benefit regarding the mortality and prophylaxis of bloodstream infection in patients with acute leukemia undergoing remission induction chemotherapy. Therefore, maintaining a CVC for as long as possible may be considered, if catheter-related bloodstream infection is not strongly suspected.

Combination versus single-agent as palliative chemotherapy for gastric cancer.

BACKGROUND: Although combination chemotherapy (CC) is generally recommended in recurrent or primary metastatic gastric cancer (RPMGC), the results of randomized trials are conflicting. METHODS: A retrospective review was conducted on 687 RPMGC patients who received palliative chemotherapy. We compared the overall survival (OS) between CC and single-agent chemotherapy (SC) among these patients, and we analyzed the clinicopathological characteristics affecting outcome including neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR). RESULTS: Although 521 patients (75.8%) underwent CC, SC was more frequently performed in elderly patients (57.6%) and ECOG performance status (PS) 2 or 3 (65.8%) patients (p < 0.0001, in each case). The median OS of patients who received CC was significantly longer than that of patients who received SC (11 vs. 8 months, p < 0.0001). No difference in OS between CC and SC was observed in elderly patients (p = 0.583), poor PS (p = 0.810), signet ring cell (p = 0.347), palliative surgical resection (p = 0.307), and high PLR (p = 0.120), with a significant interaction between age and type of regimen (p = 0.012). Moreover, there was no difference in OS between CC and SC after propensity score matching (p = 0.322). Multivariate analysis revealed that palliative resection and ≥ second-line chemotherapy were independently associated with favorable OS (p < 0.0001, in each case), whereas poor PS (p = 0.004), signet ring cell (p < 0.0001), peritoneal metastasis (p = 0.04), high NLR (p = 0.001), and high PLR (p = 0.033) were independent prognostic factors of poor OS. CONCLUSIONS: Although CC is the standard of care in RPMGC, SC can be considered a reasonable option in certain subgroups, such as elderly patients.

Abrogation of B-RafV600E induced senescence by FoxM1 expression.

B-RafV600E oncogene mutation occurs in various cancers and is associated with tumor initiation. However, genetic modification of B-RafV600E in cells induces MAPK activation and results in oncogene-induced senescence. Overcoming the oncogene-induced senescence by B-RafV600E requires activation of another oncogene pathway, such as AKT signaling. In the present study, we explored the factors involved in overcoming the senescence program in cells activated by B-RafV600E and AKT signaling. B-RafV600E activation caused a feedback inhibition of AKT phosphorylation and resulted in downregulation of FoxM1, one of the AKT downstream components. AKT activation by PTEN downregulation induced FoxM1 expression, and co-expression of B-RafV600E and FoxM1 overcame the cellular senescence. These observations suggested that FoxM1 is critical downstream gene of AKT and functions to overcome B-RafV600E-induced senescence.

Pachypodol, a Methoxyflavonoid Isolated from Pogostemon cablin Bentham Exerts Antioxidant and Cytoprotective Effects in HepG2 Cells: Possible Role of ERK-Dependent Nrf2 Activation.

Oxidative stress has been implicated in the pathogenesis of many diseases including chronic liver diseases. Nrf2 is a master transcriptional factor regulating the induction of cellular antioxidant defense systems. Here, the Nrf2-activating effect of the crude methanol extract of dried leaves of Pogostemon cablin Bentham was demonstrated by measuring the antioxidant response element (ARE)-driven luciferase activity and pachypodol, 4',5-dihydroxy-3,3',7-trimethoxyflavone, was isolated by bioactivity-guided fractionation and further separation using chromatographic techniques. To our knowledge, this is the first study to evaluate the antioxidant and cytoprotective effects of pachypodol in HepG2 cells as well as the underlying molecular mechanisms. Indeed, pachypodol protected HepG2 cells from cell death caused by tert-butylhydroperoxide-induced oxidative stress and also attenuated ROS production. The ability of pachypodol to activate Nrf2/ARE pathway was further confirmed by observing Nrf2 expression in nuclear fraction, mRNA levels of Nrf2 target antioxidants, and cellular glutathione content in HepG2 cells. Extracellular signal-regulated kinase (ERK) is one of the important kinases involved in Nrf2 activation. Pachypodol increased ERK phosphorylation and ERK inhibition by PD98059 totally abrogated the increase in ARE luciferase activity, nuclear Nrf2 accumulation and mRNA levels of antioxidant enzymes by pachypodol. In conclusion, pachypodol isolated from P. cablin can protect hepatocytes from oxidative injury, possibly mediated by enhancing endogenous antioxidant defense system through ERK-dependent Nrf2 activation.

Therapeutic application of GPR119 ligands in metabolic disorders.

GPR119 belongs to the G protein-coupled receptor family and exhibits dual modes of action upon ligand-dependent activation: pancreatic secretion of insulin in a glucose-dependent manner and intestinal secretion of incretins. Hence, GPR119 has emerged as a promising target for treating type 2 diabetes mellitus without causing hypoglycaemia. However, despite continuous efforts by many major pharmaceutical companies, no synthetic GPR119 ligand has been approved as a new class of anti-diabetic agents thus far, nor has any passed beyond phase II clinical studies. Herein, we summarize recent advances in research concerning the physiological/pharmacological effects of GPR119 and its synthetic ligands on the regulation of energy metabolism, and we speculate on future applications of GPR119 ligands for the treatment of metabolic diseases, focusing on non-alcoholic fatty liver disease.

TRPV3 Channel in Keratinocytes in Scars with Post-Burn Pruritus.

Post-burn pruritus is a common and distressing sequela of burn scars. Empirical antipruritic treatments usually fail to have a satisfactory outcome because of their limited selectivity and possible side effects. Therefore, novel drug targets need to be identified. Here, we aimed to investigate the possible role of protease-activated receptor 2 (PAR2) and transient receptor potential vanniloid 3 (TRPV3), along with the relation of TRPV3 to thymic stromal lymphopoietin (TSLP). Specimens from normal (unscarred) or burn-scarred (with or without pruritus) tissue were obtained from burn patients for this study. In each sample, the keratinocytes were isolated and cultured, and the intracellular Ca2+ level at the time of stimulation of each factor was quantified and the interaction was screened. PAR2 function was reduced by antagonism of TRPV3. Inhibiting protein kinase A (PKA) and protein kinase C (PKC) reduced TRPV3 function. TSLP mRNA and protein, and TSLPR protein expressions, increased in scars with post-burn pruritus, compared to scars without it or to normal tissues. In addition, TRPV1 or TRPV3 activation induced increased TSLP expression. Conclusively, TRPV3 may contribute to pruritus in burn scars through TSLP, and can be considered a potential therapeutic target for post-burn pruritus.

Hepatocyte-protective effect of nectandrin B, a nutmeg lignan, against oxidative stress: Role of Nrf2 activation through ERK phosphorylation and AMPK-dependent inhibition of GSK-3ß.

Oxidative stress can contribute to the development and progression of liver diseases, such as drug-induced or alcoholic liver injury, nonalcoholic fatty liver disease, and nonalcoholic steatohepatitis. Nectandrin B is a bioactive lignan isolated from nutmeg extract. To date, little information is available about its pharmacological activities in the liver. This study investigated the hepatocyte-protective effect of nectandrin B against tert-butylhydroperoxide-induced oxidative injury and the underlying molecular mechanism. The cell viability assay revealed that nectandrin B prevents apoptosis stimulated by tert-butylhydroperoxide in both HepG2 cells and primary mouse hepatocytes. Nectandrin B also attenuated ROS production and restored the depleted glutathione level. Real-time PCR and immunoblot analyses showed that the expression of glutamate-cysteine ligase, an enzyme responsible for the glutathione biosynthesis, was induced by nectandrin B, indicating its indirect antioxidative effect. The NF-E2-related factor-2 (Nrf2) regulates gene expression of an array of antioxidant enzymes in hepatocytes. Nectandrin B stimulated Nrf2 activation as evidenced by its enhanced nuclear accumulation and increased antioxidant response element (ARE)-luciferase activity. Intriguingly, the hepatocyte-protective effect of nectandrin B against oxidative damage was completely abrogated by Nrf2 knockdown using Nrf2 specific siRNA. Nectandrin B promoted ERK activation, but inactivated GSK-3ß through the AMPK-mediated inhibitory phosphorylation. The enforced overexpression of dominant-negative mutant of MEK1 or AMPKα, or wild-type GSK-3ß inhibited the increase in the NQO1-ARE-luciferase activity stimulated by nectandrin B, suggesting that both ERK and AMPK-GSK-3ß signalings are involved in the activation of Nrf2/ARE pathway by nectandrin B. Consistent with this, cytoprotection and restoration of glutathione level by nectandrin B was also blocked by the overexpression of dominant-negative MEK1 or wild-type GSK-3ß. Finally, our data demonstrate that nectandrin B has the ability to protect hepatocytes against oxidative injury through the activation of Nrf2/ARE pathway mediated by ERK phosphorylation and AMPK-dependent inactivation of GSK-3ß.

Oral Maintenance Chemotherapy with 6-Mercaptopurine and Methotrexate in Patients with Acute Myeloid Leukemia Ineligible for Transplantation.

For decades, maintenance chemotherapy has failed to improve the cure rate or prolong the survival of patients with acute myeloid leukemia (AML), other than those with acute promyelocytic leukemia. Immediately after the first complete remission following consolidation therapy was obtained, oral maintenance chemotherapy (daily 6-mercaptopurine and weekly methotrexate) was given and continued for two years in transplant-ineligible AML patients. Leukemia-free survival (LFS) and overall survival (OS) were studied and compared between these patients and the historical control group who did not receive maintenance therapy. Consecutive 52 transplant-ineligible AML patients were analyzed. Among these patients, 27 received oral maintenance chemotherapy. No significant difference was found in the patients' characteristics between the maintenance and the control groups. The median OS was 43 (95% CI, 19-67) and 19 (95% CI, 8-30) months in the maintenance and the control groups, respectively (P = 0.202). In the multivariate analysis, the presence of maintenance therapy was an independent prognostic factor for better OS (P = 0.021) and LFS (P = 0.024). Clinical benefit from maintenance chemotherapy was remarkable in older patients (≥ 60 yr) (P = 0.035), those with intermediate or unfavorable cytogenetics (P = 0.006), those with initial low blast count in peripheral blood (P = 0.044), and those receiving less than two cycles of consolidation therapy (P = 0.017). Maintenance oral chemotherapy as a post-remission therapy can prolong the survival of patients with AML who are not eligible for transplantation, particularly older patients, those with intermediate or unfavorable cytogenetics, those with initial low blast count, and those receiving less than two cycles of consolidation therapy.

Patterns of neutropenia and risk factors for febrile neutropenia of diffuse large B-cell lymphoma patients treated with rituximab-CHOP.

Febrile neutropenia (FN) is the major toxicity of rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) regimen in the treatment of diffuse large B-cell lymphoma (DLBCL). The prediction of neutropenia and FN is mandatory to continue the planned R-CHOP therapy resulting in successful anti-cancer treatment. The clinical features and patterns of neutropenia and FN from 181 DLBCL patients treated with R-CHOP were analyzed retrospectively. Sixty percent (60.2%) of patients experienced at least one episode of grade 4 neutropenia. Among them, 42.2% of episodes progressed to FN. Forty-eight percent (48.8%) of patients with FN was experienced their first FN during the first cycle of R-CHOP. All those patients never experienced FN again during the rest cycles of R-CHOP. Female, higher stage, international prognostic index (IPI), age ≥65 yr, comorbidities, bone marrow involvement, and baseline serum albumin ≤3.5 mg/dL were significant risk factors for FN by univariate analysis. Among these variables, comorbidities (P=0.009), bone marrow involvement (P=0.006), and female gender (P=0.024) were independent risk factors for FN based on multivariate analysis. On observing the patterns of neutropenia and FN, primary prophylaxis of granulocyte colony-stimulating factor (G-CSF) and antibiotics should be considered particularly in female patients, patients with comorbidities, or when there is bone marrow involvement of disease.

The influence of time of day on static and dynamic postural control in normal adults.

[Purpose] We attempted to determine whether static and dynamic postural control ability fluctuated depending on the influence of the time of day (9 am, 1 pm, and 5 pm), and at which time point postural balance performance was best in healthy individuals. [Subjects and Methods] Twenty-four healthy subjects participated in this study. The static and dynamic postural balance test was conducted during three sessions (i.e., at 9 am, 1 pm, and 5 pm) with a counterbalanced order for prevention of learning effects. As outcome measurements, AP distance, ML distance, and velocity moment were adopted in the static balance test, and the performance time and total distance were measured in the dynamic balance test. [Results] For the static postural balance test, COP distance was shorter and COP velocity was slower at 9 am compared with those at 1 and 5 pm. In particular, the COP distance at 9 am was statistically different from that at 13 pm. During the dynamic postural balance test, performance time and total distance were influenced by the time of day, as the best performance was observed in the morning. [Conclusion] This study found that static and dynamic postural balance abilities were greatest in the morning and worst at 1 pm. Understanding of the mechanism of the time-of-day effect on postural balance will be helpful for assessment and treatment of postural balance by physical therapists and in making desirable clinical decisions.

CDK4/6 inhibitors induce breast cancer senescence with enhanced anti-tumor immunogenic properties compared with DNA-damaging agents.

Since therapy-induced senescence (TIS) can either support or inhibit cancer progression, identifying which types of chemotherapeutic agents can produce the strongest anti-tumor TIS is an important issue. Here, cyclin-dependent kinase4/6 inhibitors (CDK4/6i)-induced senescence was compared to the TIS induced by conventional DNA-damaging agents. Despite both types of agents eliciting a similar degree of senescence, we observed increased expression of the senescence-associated secretory phenotype (SASP) and ligands related to pro-tumor immunity (IL6, CXCL8, TGFß, CD274, and CEACAM1) and angiogenesis (VEGFA) mainly in TIS induced by DNA-damaging agents rather than by CDK4/6i. Additionally, although all agents increased the expression of anti-tumor immunomodulatory proteins related to antigen presentation (MHC-I, B2M) and T cell chemokines (CXCL9, 10, 11), CDK4/6i-induced senescent cells still maintained this expression at a similar or even higher intensity than cells treated with DNA-damaging agents, despite the absence of nuclear factor-kappa-B (NF-κB) and p53 activation. These data suggest that in contrast with DNA-damaging agents, which augment the pro-tumorigenic microenvironment via pro-inflammatory SASP, CDK4/6i can generate TIS only with antitumor immunomodulatory proteins.

Cellular senescence is associated with the spatial evolution toward a higher metastatic phenotype in colorectal cancer.

In this study, we explore the dynamic process of colorectal cancer progression, emphasizing the evolution toward a more metastatic phenotype. The term "evolution" as used in this study specifically denotes the phenotypic transition toward a higher metastatic potency from well-formed glandular structures to collective invasion, ultimately resulting in the development of cancer cell buddings at the invasive front. Our findings highlight the spatial correlation of this evolution with tumor cell senescence, revealing distinct types of senescent tumor cells (types I and II) that play different roles in the overall cancer progression. Type I senescent tumor cells (p16INK4A+/CXCL12+/LAMC2-/MMP7-) are identified in the collective invasion region, whereas type II senescent tumor cells (p16INK4A+/CXCL12+/LAMC2+/MMP7+), representing the final evolved form, are prominently located in the partial-EMT region. Importantly, type II senescent tumor cells associate with local invasion and lymph node metastasis in colorectal cancer, potentially affecting patient prognosis.

Signals regulating necrosis of cardiomyoblast by BTG2(/TIS21/PC3) via activation of GSK3ß and opening of mitochondrial permeability transition pore in response to H2O2.

To investigate signal transduction pathway of cell death regulated by a tumor suppressor after oxidative stress, cardiomyoblasts were virally transfected with BTG2(/TIS21/PC3) (BTG2) and subsequently treated with H2O2. Heart muscle rarely expresses BTG2 unless oxidative stress occurs, however, ischemia induced BTG2 expression and necrosis, not apoptosis, of cardiomyoblasts. BTG2-expressioning cardiomyblasts showed impaired recoveries of survival kinases, Akt and Erk, thus sustaining GSK-3ß activity in 30 min of H2O2 exposure, in contrast to their rapid recoveries in LacZ control. The phenomenon was accompanied by the failure of ATP regeneration and the sustained activation of AMPK in the BTG2 expresser. Furthermore, H2O2 treatment markedly induced BTG2 translocation from nuclei to mitochondria along with cell death by cyclophilin D activation and mPTP opening. Exogenous and endogenous effect of BTG2 was confirmed by chemical inhibitors and BTG2-KO-MEF, respectively. Here, we suggest tumor suppressor, BTG2, as one of the regulators of necrosis in myocardium via inhibiting Akt/Erk, but activating GSK3ß and cyclophilin D, which resulted in mPTP opening in response to H2O2.

Gankyrin is frequently overexpressed in breast cancer and is associated with ErbB2 expression.

Gankyrin is a subunit of the 26S proteasome, and has been known to degrade p53 and retinoblastoma protein and promote the tumorigenicity and metastasis in some malignancies. However, the role of gankyrin in breast cancer has not been explored. In this study, we investigated the expression of gankyrin in breast cancer and evaluated its effect on breast cancer. Representative cancer tissues including normal breasts from 60 patients with breast cancer were stained immunohistochemically for gankyrin, estrogen receptor, progesterone receptor, and ErbB2. We evaluated the relationship between gankyrin expression and clinicopathologic parameters or prognostic markers. We also attempted to clarify the mechanism of gankyrin involved in breast carcinogenesis by using MCF7 breast cancer cells. Gankyrin was weakly expressed in normal breast epithelial cells, however, tumor regions of 37/60 (61.7%) cases showed an overexpression of gankyrin. Gankyrin overexpression was associated with extensive intraductal carcinoma (p=0.014) and ErbB2 positivity (p=0.031) in invasive ductal carcinoma. In MCF7 breast cancer cells, downregulation of gankyrin was associated with a reduction of cell proliferation and tumorigenicity. In conclusion, gankyrin was identified in normal breasts and overexpressed in invasive breast cancers. The overexpression of gankyrin was associated with extensive intraductal carcinoma and ErbB2 expression in breast cancer.

p15INK4B is an alternative marker of senescent tumor cells in colorectal cancer.

Senescent tumor cells are nonproliferating tumor cells which are closely related to cancer progression by secreting senescence-related molecules, called senescence-associated secreting phenotypes. Therefore, the presence of senescent tumor cells is considered a prognostic factor in various cancer types. Although senescence-associated ß-galactosidase staining is considered the best marker for detection of senescent tumor cells, it can only be performed in fresh-frozen tissues. p16INK4A, a cyclin-dependent inhibitor, has been used as an alternative marker to detect senescent tumor cells in formalin-fixed paraffin-embedded tissues. However, other reliable markers to detect senescent tumor cells is still lacking. In the present study, using public single-cell RNA-sequencing data, we found that p15INK4B, a cyclin-dependent kinase inhibitor, is a novel marker for detection of senescent tumor cells. Moreover, p15INK4B expression was positively correlated with that of p16INK4A in colorectal cancer tissues. In in vitro studies, mRNA expression of p15INK4B was increased together with that of p16INK4A in H2O2- and therapy-induced cancer senescence models. However, the mRNA level of p15INK4B did not increase in the oncogene-induced senescence model in primary colonic epithelial cells. In conclusion, p15INK4B is a potential alternative marker for detection of senescent tumor cells together with conventional markers in advanced stages of colorectal cancer.